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  • richardmitnick 10:05 pm on June 30, 2022 Permalink | Reply
    Tags: "H1821+243:: Chandra Shows Giant Black Hole Spins Slower Than Its Peers", , Ground based Optical Astronomy, , ,   

    From NASA Chandra: “H1821+243:: Chandra Shows Giant Black Hole Spins Slower Than Its Peers” 

    NASA Chandra Banner

    From NASA Chandra

    June 30, 2022

    Megan Watzke
    Chandra X-ray Center, Cambridge, Massachusetts
    617-496-7998
    mwatzke@cfa.harvard.edu

    1
    Composite
    Credit: X-ray: NASA/CXC/Univ. of Cambridge/J. Sisk-Reynés et al.; Radio: NSF/NRAO/VLA; Optical: PanSTARRS

    2
    X-ray

    3
    Optical

    4
    Radio

    Astronomers have gauged how fast a supermassive black hole is spinning inside a quasar 3.4 billion light years away.

    Using Chandra data, they found it is rotating at about half the speed of light.

    This remarkable speed is still much slower than many less massive black holes, providing clues to how this black hole grew.

    Scientists think that nearly every galaxy, including the Milky Way, has a giant black hole at its center.
    _________________________________________________________________________

    H1821+643 is a quasar powered by a supermassive black hole, located about 3.4 billion light years from Earth. Astronomers used /about/ to determine the spin of the black hole in H1821+643, making it the most massive one to have an accurate measurement of this fundamental property, as described in our press release. Astronomers estimate the actively growing black hole in H1821+643 contains between about three and 30 billion solar masses, making it one of the most massive known. By contrast the supermassive black hole in the center of the Milky Way galaxy weighs about four million suns.

    This composite image of H1821+643 contains X-rays from Chandra (blue) that have been combined with radio data from NSF’s Karl G. Jansky Very Large Array (red) and an optical image from the PanSTARRS telescope on Hawaii (white and yellow). The researchers used nearly a week’s worth of Chandra observing time, taken over two decades ago, to obtain this latest result. The supermassive black hole is located in the bright dot in the center of the radio and X-ray emission.

    Because a spinning black hole drags space around with it and allows matter to orbit closer to it than is possible for a non-spinning one, the X-ray data can show how fast the black hole is spinning. The spectrum — that is, the amount of energy as a function wavelength — of H1821+643 indicates that the black hole is rotating at a modest rate compared to other, less massive ones that spin close to the speed of light. This is the most accurate spin measurement for such a massive black hole.

    Why is the black hole in H1821+432 spinning only about half as fast as the lower mass cousins? The answer may lie in how these supermassive black holes grow and evolve. This relatively slow spin supports the idea that the most massive black holes like H1821+643 undergo most of their growth by merging with other black holes, or by gas being pulled inwards in random directions when their large disks are disrupted.

    Supermassive black holes growing in these ways are likely to often undergo large changes of spin, including being slowed down or wrenched in the opposite direction. The prediction is therefore that the most massive black holes should be observed to have a wider range of spin rates than their less massive relatives.

    On the other hand, scientists expect less massive black holes to accumulate most of their mass from a disk of gas spinning around them. Because such disks are expected to be stable, the incoming matter always approaches from a direction that will make the black holes spin faster until they reach the maximum speed possible, which is the speed of light.

    A paper describing these results appears in the MNRAS. The authors are Julia Sisk-Reynes, Christopher Reynolds, James Matthews, and Robyn Smith, all from the Institute of Astronomy at the University of Cambridge in the UK.

    See the full article here .


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    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.
    In 1976 the Chandra X-ray Observatory (called AXAF at the time) was proposed to National Aeronautics and Space Administration by Riccardo Giacconi and Harvey Tananbaum. Preliminary work began the following year at NASA’s Marshall Space Flight Center and the Harvard Smithsonian Center for Astrophysics. In the meantime, in 1978, NASA launched the first imaging X-ray telescope, Einstein (HEAO-2), into orbit. Work continued on the AXAF project throughout the 1980s and 1990s. In 1992, to reduce costs, the spacecraft was redesigned. Four of the twelve planned mirrors were eliminated, as were two of the six scientific instruments. AXAF’s planned orbit was changed to an elliptical one, reaching one third of the way to the Moon’s at its farthest point. This eliminated the possibility of improvement or repair by the space shuttle but put the observatory above the Earth’s radiation belts for most of its orbit. AXAF was assembled and tested by TRW (now Northrop Grumman Aerospace Systems) in Redondo Beach, California.

    AXAF was renamed Chandra as part of a contest held by NASA in 1998, which drew more than 6,000 submissions worldwide. The contest winners, Jatila van der Veen and Tyrel Johnson (then a high school teacher and high school student, respectively), suggested the name in honor of Nobel Prize–winning Indian-American astrophysicist Subrahmanyan Chandrasekhar. He is known for his work in determining the maximum mass of white dwarf stars, leading to greater understanding of high energy astronomical phenomena such as neutron stars and black holes. Fittingly, the name Chandra means “moon” in Sanskrit.

    Originally scheduled to be launched in December 1998, the spacecraft was delayed several months, eventually being launched on July 23, 1999, at 04:31 UTC by Space Shuttle Columbia during STS-93. Chandra was deployed from Columbia at 11:47 UTC. The Inertial Upper Stage’s first stage motor ignited at 12:48 UTC, and after burning for 125 seconds and separating, the second stage ignited at 12:51 UTC and burned for 117 seconds. At 22,753 kilograms (50,162 lb), it was the heaviest payload ever launched by the shuttle, a consequence of the two-stage Inertial Upper Stage booster rocket system needed to transport the spacecraft to its high orbit.

    Chandra has been returning data since the month after it launched. It is operated by the SAO at the Chandra X-ray Center in Cambridge, Massachusetts, with assistance from Massachusetts Institute of Technology and Northrop Grumman Space Technology. The ACIS CCDs suffered particle damage during early radiation belt passages. To prevent further damage, the instrument is now removed from the telescope’s focal plane during passages.

    Although Chandra was initially given an expected lifetime of 5 years, on September 4, 2001, NASA extended its lifetime to 10 years “based on the observatory’s outstanding results.” Physically Chandra could last much longer. A 2004 study performed at the Chandra X-ray Center indicated that the observatory could last at least 15 years.

    In July 2008, the International X-ray Observatory, a joint project between European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU), NASA and Japan Aerospace Exploration Agency (JAXA) (国立研究開発法人宇宙航空研究開発機構], was proposed as the next major X-ray observatory but was later cancelled. ESA later resurrected a downsized version of the project as the Advanced Telescope for High Energy Astrophysics (ATHENA), with a proposed launch in 2028.

    European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Athena spacecraft depiction

    On October 10, 2018, Chandra entered safe mode operations, due to a gyroscope glitch. NASA reported that all science instruments were safe. Within days, the 3-second error in data from one gyro was understood, and plans were made to return Chandra to full service. The gyroscope that experienced the glitch was placed in reserve and is otherwise healthy.

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [NASA/ESA Hubble, NASA Chandra, NASA Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 10:04 am on June 30, 2022 Permalink | Reply
    Tags: "Gemini North Spies Ultra-Faint Fossil Galaxy Discovered on Outskirts of Andromeda", Ground based Optical Astronomy, NSF’s NOIRLab facilities reveal a relict of the earliest galaxies., The galaxy called Pegasus V, ,   

    From The NSF NOIRLab NOAO Gemini Observatory and The University of Surrey (UK): “Gemini North Spies Ultra-Faint Fossil Galaxy Discovered on Outskirts of Andromeda” 



    Gemini Observatory

    From The NSF NOIRLab NOAO Gemini Observatory

    and

    The University of Surrey (UK)

    30 June 2022

    Michelle Collins
    University of Surrey
    Email: m.collins@surrey.ac.uk

    Amanda Kocz
    Communications Manager
    NSF’s NOIRLab
    Tel: +1 520 318 8591
    Email: amanda.kocz@noirlab.edu

    NSF’s NOIRLab facilities reveal a relict of the earliest galaxies.

    1
    A unique ultra-faint dwarf galaxy has been discovered in the outer fringes of the Andromeda Galaxy thanks to the sharp eyes of an amateur astronomer examining archival data from the US Department of Energy-fabricated Dark Energy Camera [below] on the Víctor M. Blanco 4-meter Telescope [below] at Cerro Tololo Inter-American Observatory (CTIO)[below] and processed by the Community Science and Data Center (CSDC). Follow-up by professional astronomers using the International Gemini Observatory [Gemini North below] revealed that the dwarf galaxy — Pegasus V — contains very few heavier elements and is likely to be a fossil of the first galaxies. All three facilities involved are Programs of NSF’s NOIRLab. Credit: International Gemini Observatory/NOIRLab/NSF/AURA. Acknowledgment: Image processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), M. Zamani (NSF’s NOIRLab) & D. de Martin (NSF’s NOIRLab).

    Cosmoview Episode 46: Gemini North Spies Ultra-Faint Fossil Galaxy Discovered on Outskirts of Andromeda

    Images and Videos: International Gemini Observatory/KPNO/NOIRLab/NSF/AURA/K. Pu’uohau-Pummill/Adam Block
    Image Processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), M. Zamani (NSF’s NOIRLab) & D. de Martin (NSF’s NOIRLab) Music:Stellardrone – In Time.

    An unusual ultra-faint dwarf galaxy has been discovered on the edge of the Andromeda Galaxy using several facilities of NSF’s NOIRLab. The galaxy called Pegasus V, was first detected as part of a systematic search for Andromeda dwarfs coordinated by David Martinez-Delgado from the Instituto de Astrofísica de Andalucía, Spain, when amateur astronomer Giuseppe Donatiello found an interesting ‘smudge’ in data in a DESI Legacy Imaging Surveys image [1]. The image was taken with the US Department of Energy-fabricated Dark Energy Camera on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO). The data were processed through the Community Pipeline which is operated by NOIRLab’s Community Science and Data Center (CSDC).

    Follow-up deeper observations by astronomers using the larger, 8.1-meter Gemini North telescope with the GMOS instrument, revealed faint stars in Pegasus V, confirming that it is an ultra-faint dwarf galaxy on the outskirts of the Andromeda Galaxy. Gemini North in Hawai‘i is one half of the International Gemini Observatory.

    The observations with Gemini revealed that the galaxy appears to be extremely deficient in heavier elements compared to similar dwarf galaxies, meaning that it is very old and likely to be a fossil of the first galaxies in the Universe.

    “We have found an extremely faint galaxy whose stars formed very early in the history of the Universe,” commented Michelle Collins, an astronomer at the University of Surrey, UK and lead author of the paper announcing this discovery. “This discovery marks the first time a galaxy this faint has been found around the Andromeda Galaxy using an astronomical survey that wasn’t specifically designed for the task.”

    The faintest galaxies are considered to be fossils of the very first galaxies that formed, and these galactic relics contain clues about the formation of the earliest stars. While astronomers expect the Universe to be teeming with faint galaxies like Pegasus V [2], they have not yet discovered nearly as many as their theories predict. If there are truly fewer faint galaxies than predicted this would imply a serious problem with astronomers’ understanding of cosmology and dark matter.

    Discovering examples of these faint galaxies is therefore an important endeavor, but also a difficult one. Part of the challenge is that these faint galaxies are extremely tricky to spot, appearing as just a few sparse stars hidden in vast images of the sky.

    “The trouble with these extremely faint galaxies is that they have very few of the bright stars which we typically use to identify them and measure their distances,” explained Emily Charles, a PhD student at the University of Surrey who was also involved in the study. “Gemini’s 8.1-meter mirror allowed us to find faint, old stars which enabled us both to measure the distance to Pegasus V and to determine that its stellar population is extremely old.”

    The strong concentration of old stars that the team found in Pegasus V suggests that the object is likely a fossil of the first galaxies. When compared with the other faint galaxies around Andromeda, Pegasus V seems uniquely old and metal-poor, indicating that its star formation ceased very early indeed.

    “We hope that further study of Pegasus V’s chemical properties will provide clues into the earliest periods of star formation in the Universe,” concluded Collins. “This little fossil galaxy from the early Universe may help us understand how galaxies form, and whether our understanding of dark matter is correct.”

    “The public-access Gemini North telescope provides an array of capabilities for community astronomers,” said Martin Still, Gemini Program Officer at the National Science Foundation. “In this case, Gemini supported this international team to confirm the presence of the dwarf galaxy, associate it physically with the Andromeda Galaxy, and determine the metal-deficient nature of its evolved stellar population.”

    Upcoming astronomical facilities are set to shed more light on faint galaxies. Pegasus V was witness to a time in the history of the Universe known as reionization, and other objects dating back to this time will soon be observed with NASA’s James Webb Space Telescope.

    Astronomers also hope to discover other such faint galaxies in the future using Vera C. Rubin Observatory, a Program of NSF’s NOIRLab.

    Rubin Observatory will conduct an unprecedented, decade-long survey of the optical sky called the Legacy Survey of Space and Time (LSST).

    Notes:

    [1] The DESI Legacy Imaging Surveys were conducted to identify targets for the Dark Energy Spectroscopic Instrument (DESI) operations.


    These surveys comprise a unique blend of three projects that have observed a third of the night sky: the Dark Energy Camera Legacy Survey (DECaLS), observed by the DOE-built Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile; the Mayall z-band Legacy Survey (MzLS), by the Mosaic3 camera on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (KPNO); and the Beijing-Arizona Sky Survey (BASS) by the 90Prime camera on the Bok 2.3-meter Telescope, which is owned and operated by the University of Arizona and located at KPNO. CTIO and KPNO are Programs of NSF’s NOIRLab.

    [2] Pegasus V is so named because it is the fifth dwarf galaxy discovered located in the constellation Pegasus. The on-sky separation between Pegasus V and the Andromeda Galaxy is about 18.5 degrees.

    More information

    This research was presented in a paper to appear in MNRAS Letters.

    The team is composed of Michelle L. M. Collins (Physics Department, University of Surrey, UK), Emily J. E. Charles (Physics Department, University of Surrey, UK), David Martínez-Delgado (Instituto de Astrofísica de Andalucía, Spain), Matteo Monelli (Instituto de Astrofísica de Canarias (IAC) and Universidad de La Laguna, Spain), Noushin Karim (Physics Department, University of Surrey, UK), Giuseppe Donatiello (UAI – Unione Astrofili Italiani, Italy), Erik J. Tollerud (Space Telescope Science Institute, USA), Walter Boschin (Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, and Fundación G. Galilei – INAF (Telescopio Nazionale Galileo), Spain).

    See the full article here .


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    Please help promote STEM in your local schools.

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    About The University of Surrey (UK)

    The University of Surrey is a public research university in Guildford, Surrey, England. The university received its royal charter in 1966, along with a number of other institutions following recommendations in the Robbins Report. The institution was previously known as Battersea College of Technology and was located in Battersea Park, London. Its roots however, go back to Battersea Polytechnic Institute, founded in 1891 to provide further and higher education in London, including its poorer inhabitants. The university’s research output and global partnerships have led to it being regarded as one of the UK’s leading research universities.

    The university is a member of the Association of MBAs and is one of four universities in the University Global Partnership Network. It is also part of the SETsquared partnership (UK) along with The University of Bath (UK), The University of Bristol (UK), the University of Southampton (UK) and The University of Exeter (UK). The university’s main campus is on Stag Hill, close to the centre of Guildford and adjacent to Guildford Cathedral. Surrey Sports Park is situated at the nearby Manor Park, the university’s secondary campus. Among British universities, the University of Surrey had the 14th highest average UCAS Tariff for new entrants in 2015.

    A major centre for satellite and mobile communications research, the university is in partnership with King’s College London (UK) and the Dresden University of Technology [Technische Universität Dresden] (DE) to develop 5G technology worldwide. It also holds a number of formal links with institutions worldwide, including the Surrey International Institute (UK), launched in partnership with the Dongbei University of Finance and Economics [东北财经大学](DUFE) (CN). The university owns the Surrey Research Park, providing facilities for over 110 companies engaged in research. Surrey has been awarded three Queen’s Anniversary Prizes for its research, with the 2014 Research Excellence Framework ranking 78% of the university’s research outputs as “world leading” or “internationally excellent”. It was named as The Sunday Times University of the Year in 2016.

    Current and emeritus academics at the university include ten Fellows of the Royal Society, twenty-one Fellows of the Royal Academy of Engineering, one Fellow of the British Academy and six Fellows of the Academy of Social Sciences. Surrey has educated many notable alumni, including Olympic gold medallists, several senior politicians, as well as a number of notable persons in various fields including the arts, sports and academia. Graduates typically abbreviate the University of Surrey to Sur when using post-nominal letters after their degree.

    Research

    The university conducts extensive research on small satellites, with its Surrey Space Centre and spin-off commercial company, Surrey Satellite Technology Ltd. In the 2001 Research Assessment Exercise, the University of Surrey received a 5* rating in the categories of “Sociology”, “Other Studies and Professions Allied to Medicine”, and “Electrical and Electronic Engineering” and a 5* rating in the categories of “Psychology”, “Physics”, “Applied Mathematics”, “Statistics and Operational Research”, “European Studies” and “Russian, Slavonic and East European Languages”.

    The 5G Innovation Centre (5GIC) at the University of Surrey opened in September 2015, for the purpose of research for the development of the first worldwide 5G network. It has gained over £40m support from international telecommunications companies including Aeroflex, MYCOM OSI, BBC, BT Group, EE (telecommunications company), Fujitsu Laboratories of Europe, Huawei, Ofcom, Rohde & Schwarz, Samsung, Telefonica and Vodafone – and a further £11.6m from the Higher Education Funding Council for England (HEFCE).

    In addition, the Surrey Research Park is a 28 ha (69-acre) low density development which is owned and developed by the university, providing large landscaped areas with water features and facilities for over 110 companies engaged in a broad spectrum of research, development and design activities. The university generates the third highest endowment income out of all UK universities “reflecting its commercially-orientated heritage.”

    NSF NOIRLab NOAO Cerro Tololo Inter-American Observatory(CL) approximately 80 km to the East of La Serena, Chile, at an altitude of 2200 meters.


    Gemini’s mission is to advance our knowledge of the Universe by providing the international Gemini Community with forefront access to the entire sky.

    The NSF NOIRLab Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai’i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.

    The Gemini Observatory provides the astronomical communities in six partner countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country’s contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Australian Research Council (ARC), the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva, and the Brazilian Ministério da Ciência, Tecnologia e Inovação. The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.

    National Science Foundation’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory ), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, National Research Council Canada (CA), Agancia Nacional de IInvestigacion y Desarrollo (CL), Ministry of Science, Technology and Innovation [Ministério da Ciência, Tecnologia e Inovações] (BR), <a href="http://“>Ministry of Science, Technology and Innovation | Argentina.gob.Ministerio de Ciencia, Tecnología e Innovación | Argentina.gob.(AR), and Korea Astronomy and Space Science Institute[알림사항](KR), Kitt Peak National Observatory (KPNO) , NSF NOAO Cerro Tololo Inter-American Observatory (CL), the NOAO Community Science and Data Center (CSDC), and Vera C. Rubin Observatory in cooperation with DOE’s SLAC National Accelerator Laboratory ).



    It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with National Science Foundation and is headquartered in Tucson, Arizona.
    The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawaiʻi, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

     
  • richardmitnick 3:39 pm on June 23, 2022 Permalink | Reply
    Tags: "A star’s demise is connected to a neutrino outburst", , Ground based Neutrino Observation, Ground based Optical Astronomy, , , On 1 October 2019 the IceCube Neutrino Observatory in Antarctica detected a 0.2 PeV neutrino., , , , Recently the Zwicky Transient Facility observed another TDE that was coincident with a high-energy neutrino detected by IceCube., Seven hours later the Zwicky Transient Facility observed optical an emission in the direction of the incoming neutrino., , The optical emission was caused by a bright transient phenomenon known as a tidal disruption event (TDE)., The prospect of high-energy neutrinos being formed by tidal forces ripping apart a star near a supermassive black hole has garnered new support.   

    From “Physics Today” : “A star’s demise is connected to a neutrino outburst” 

    Physics Today bloc

    From “Physics Today”

    23 Jun 2022
    Alex Lopatka

    The prospect of high-energy neutrinos being formed by tidal forces ripping apart a star near a supermassive black hole has garnered new support.

    (S. Reusch et al., Phys. Rev. Lett. 128, 221101, 2022.)

    1
    Technicians install a camera at the Zwicky Transient Facility. Credit: Caltech/Palomar.

    On 1 October 2019 the IceCube Neutrino Observatory in Antarctica detected a 0.2 PeV neutrino.

    Seven hours later the Zwicky Transient Facility in California followed up with a wide-field survey of the sky at optical and IR wavelengths. The facility observed optical emission in the direction of the incoming neutrino.

    Researchers concluded [Nature Astronomy] that the two observations could be connected after studying the exceptional energy flux of the emission, its location within the reported uncertainty region of the high-energy neutrino, and some modeling results. The optical emission was caused by a bright transient phenomenon known as a tidal disruption event (TDE), and that particular one had first been observed one year before the neutrino. Such events occur when stars get close enough to supermassive black holes to experience spaghettification—the stretching and compression of an object into a long, thin shape due to the black hole’s extreme tidal forces. (See the article by Suvi Gezari, Physics Today, May 2014, page 37.)

    A theory paper [Nature Astronomy] proposed that neutrinos with energies above 100 TeV, like the 2019 sighting, could be produced in relativistic jets of plasma, which are composed of stellar debris that’s flung outward after such an event. TDEs and many other sources for high-energy neutrinos have been debated in the literature. But with only one reported TDE–neutrino association researchers haven’t been able to conclusively establish TDEs as high-energy neutrino sources.

    3
    Credit: S. Reusch et al., Phys. Rev. Lett. 128, 221101 (2022)

    Recently the Zwicky Transient Facility observed another TDE that was coincident with a high-energy neutrino detected by IceCube. Simeon Reusch, Marek Kowalski, and their colleagues estimated that the probability of a second such pairing happening by chance is 0.034%, lending more credence to TDEs as a source for high-energy neutrinos.

    The second TDE caused a long-duration optical flare which reached its peak luminosity in August 2019. The neutrino was detected by IceCube in May 2020, by which point the flare’s flux had decreased by about 30% from its peak. Such flares often last several months, though this one was still detectable as of June 2022.

    To better understand how the unusually long-lasting TDE may have produced high-energy neutrinos, the research team simulated three mechanisms. The figure shows the predicted neutrino flux as a function of energy, and the vertical dotted line indicates the energy of the neutrino observed by IceCube. Any of the three mechanisms could reasonably explain the neutrino. Besides relativistic jets, a TDE could also generate an accretion disk, and emission from its corona or a subrelativistic wind of ejected material may generate neutrinos too.

    Other uncertainties remain. The radio-emission measurements of the flare, for example, mean that it could have originated from an active galactic nucleus instead of a TDE. In addition, IceCube’s statistical analysis cannot rule out that the neutrino may have formed from atmospheric processes on Earth.

    Although it’ll take more observations to lower those uncertainties, the latest detection of a TDE–neutrino pairing reinforces the significance of TDEs as neutrino sources. And if the association is true, TDEs would have to be surprisingly efficient particle accelerators, a possibility that could only be further studied with more comprehensive multimessenger data.

    See the full article here .

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    Please help promote STEM in your local schools.

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    “Our mission

    The mission of ”Physics Today” is to be a unifying influence for the diverse areas of physics and the physics-related sciences.

    It does that in three ways:

    • by providing authoritative, engaging coverage of physical science research and its applications without regard to disciplinary boundaries;
    • by providing authoritative, engaging coverage of the often complex interactions of the physical sciences with each other and with other spheres of human endeavor; and
    • by providing a forum for the exchange of ideas within the scientific community.”

     
  • richardmitnick 9:53 am on June 22, 2022 Permalink | Reply
    Tags: "NASA’s Webb to Uncover Riches of the Early Universe", Ground based Optical Astronomy, , ,   

    From The NASA/ESA/CSA James Webb Space Telescope: “NASA’s Webb to Uncover Riches of the Early Universe” 

    NASA Webb Header

    National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) James Webb Infrared Space Telescope annotated, finally launched December 25, 2021, ten years late.

    From The NASA/ESA/CSA James Webb Space Telescope

    June 22, 2022

    Claire Blome
    Space Telescope Science Institute, Baltimore, Maryland

    Christine Pulliam
    Space Telescope Science Institute, Baltimore, Maryland

    Outlines of Webb’s Ultra Deep Field Observations

    1
    This image shows where the James Webb Space Telescope will observe the sky within the Hubble Ultra Deep Field, which consists of two fields. The Next Generation Deep Extragalactic Exploratory Public (NGDEEP) Survey, led by Steven L. Finkelstein, will point Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) on the primary Hubble Ultra Deep Field (shown in orange), and Webb’s Near-Infrared Camera (NIRCam) on the parallel field (shown in red). The program led by Michael Maseda will observe the primary field (shown in blue) using Webb’s Near-Infrared Spectrograph (NIRSpec). Credits: SCIENCE: NASA, ESA, Anton M. Koekemoer (STScI) ILLUSTRATION: Alyssa Pagan (STScI).

    Summary

    Two research teams will use the telescope’s powerful instruments to capture and characterize some of the earliest galaxies in the universe.

    The universe was a very different place for several hundred million years after the big bang. It wasn’t yet transparent like it is today – neutral gas made it semi-opaque. This is a period when the first galaxies in the universe were beginning to form. Telescopes have spotted many distant galaxies – but none earlier than 400 million years after the big bang. What were galaxies that existed even earlier like? Two research teams using the James Webb Space Telescope will wield its state-of-the-art instruments to reveal an untold number of details about this early period in the universe for the first time – and revise what we know about some of the earliest chapters of galaxy evolution.
    __________________________________________________________

    Hubble Ultra Deep Field
    3
    This Hubble Space Telescope image, known as the Hubble Ultra Deep Field, reveals about 10,000 galaxies and combines ultraviolet, visible, and near-infrared light. Two programs that will use the James Webb Space Telescope will add more detail to this image, capturing thousands of additional galaxies in a fuller range of infrared light. Webb will return both imagery and data known as spectra, providing more details about some of the earliest galaxies to exist in the universe for the first time.

    This image was captured before the launch of the James Webb Space Telescope. No Webb data are shown in this image.
    Credits: SCIENCE: NASA, ESA, Steven V.W. Beckwith (STScI), HUDF Team (STScI).

    For decades, telescopes have helped us capture light from galaxies that formed as far back as 400 million years after the big bang – incredibly early in the context of the universe’s 13.8-billion-year history. But what were galaxies like that existed even earlier, when the universe was semi-transparent at the beginning of a period known as the Era of Reionization? NASA’s next flagship observatory, the James Webb Space Telescope, is poised to add new riches to our wealth of knowledge not only by capturing images from galaxies that existed as early as the first few hundred million years after the big bang, but also by giving us detailed data known as spectra. With Webb’s observations, researchers will be able to tell us about the makeup and composition of individual galaxies in the early universe for the first time.

    The Next Generation Deep Extragalactic Exploratory Public (NGDEEP) Survey, co-led by Steven L. Finkelstein, an associate professor at the University of Texas at Austin, will target the same two regions that make up the Hubble Ultra Deep Field – locations in the constellation Fornax where Hubble spent more than 11 days taking deep exposures. To produce its observations, the Hubble Space Telescope targeted nearby areas of the sky simultaneously with two instruments – slightly offset from one another – known as a primary and a parallel field. “We have the same advantage with Webb,” Finkelstein explained. “We’re using two science instruments at once, and they will observe continuously.” They will point Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) on the primary Hubble Ultra Deep Field, and Webb’s Near-Infrared Camera (NIRCam)[below] on the parallel field, getting twice the bang for their “buck” of telescope time.

    For the imaging with NIRCam, they’ll observe for over 125 hours. With each passing minute, they’ll obtain more and more information from deeper and deeper in the universe. What do they seek? Some of the earliest galaxies that formed. “We have really good indications from Hubble that there are galaxies in place at a time 400 million years after the big bang,” Finkelstein said. “The ones we see with Hubble are pretty big and very bright. It’s highly likely there are smaller, fainter galaxies that formed even earlier that are waiting to be found.”

    This program will use only about one-third of the time Hubble has spent to date on similar investigations. Why? In part, this is because Webb’s instruments were designed to capture infrared light. As light travels through space toward us, it stretches into longer, redder wavelengths due to the expansion of the universe. “Webb will help us push all the boundaries,” said Jennifer Lotz, a coinvestigator on the proposal and director of the Gemini Observatory, part of the National Science Foundation’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory). “And we’re going to release the data immediately to benefit all researchers.”

    These researchers will also focus on identifying the metal content in each galaxy, especially in smaller and dimmer galaxies that haven’t yet been thoroughly examined – specifically with the spectra Webb’s NIRISS [below] instrument delivers. “One of the fundamental ways that we trace evolution across cosmic time is by the amount of metals that are in a galaxy,” explained Danielle Berg, an assistant professor at the University of Texas at Austin and a co-investigator on the proposal. When the universe began, there was only hydrogen and helium. New elements were formed by successive generations of stars. By cataloging the contents of each galaxy, the researchers will be able to plot out precisely when various elements existed and update models that project how galaxies evolved in the early universe.

    Peeling Back New Layers

    Another program, led by Michael Maseda, an assistant professor at the University of Wisconsin-Madison, will examine the primary Hubble Ultra Deep Field using the microshutter array within Webb’s Near-Infrared Spectrograph (NIRSpec)[below]. This instrument returns spectra for specific objects depending on which miniature shutters researchers open. “These galaxies existed during the first billion years in the history of the universe, which we have very little information about to date,” Maseda explained. “Webb will provide the first large sample that will give us the chance to understand them in detail.”

    We know these galaxies exist because of extensive observations this team has made – along with an international research team – with the ground-based Very Large Telescope’s Multi Unit Spectroscopic Explorer (MUSE) instrument.

    Although MUSE is the “scout,” identifying smaller, fainter galaxies in this deep field, Webb will be the first telescope to fully characterize their chemical compositions.

    These extremely distant galaxies have important implications for our understanding of how galaxies formed in the early universe. “Webb will open a new space for discovery,” explained Anna Feltre, a research fellow at the National Institute for Astrophysics in Italy and a co-investigator. “Its data will help us learn precisely what happens as a galaxy forms, including which metals they contain, how quickly they grow, and if they already have black holes.”

    This research will be conducted as part of Webb’s General Observer (GO) programs, which are competitively selected using a dual-anonymous review, the same system that is used to allocate time on the Hubble Space Telescope.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The NASA/ESA/CSA James Webb Space Telescope is a large infrared telescope with a 6.5-meter primary mirror. Webb was finally launched December 25, 2021, ten years late. The James Webb Space Telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    The James Webb Space Telescope is the world’s largest, most powerful, and most complex space science telescope ever built. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it.

    Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between National Aeronautics and Space Administration, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center managed the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute will operate Webb after launch.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There are four science instruments on Webb: The Near InfraRed Camera (NIRCam), The Near InfraRed Spectrograph (NIRspec), The Mid-InfraRed Instrument (MIRI), and The Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments are designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.
    National Aeronautics Space Agency Webb NIRCam.

    The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Webb NIRspec.

    The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Webb MIRI schematic.

    Webb Fine Guidance Sensor-Near InfraRed Imager and Slitless Spectrograph FGS/NIRISS.

    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch was December 25, 2021 on an Ariane 5 rocket. The launch was from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb is located at the second Lagrange point, about a million miles from the Earth.

    ESA50 Logo large

    Canadian Space Agency

     
  • richardmitnick 4:00 pm on June 16, 2022 Permalink | Reply
    Tags: "New Images Using Data From Retired Telescopes Reveal Hidden Features", , , , Ground based Optical Astronomy, ,   

    From Hubblesite: “New Images Using Data From Retired Telescopes Reveal Hidden Features” 

    National Aeronautics and Space Administration/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne] [Europäische Weltraumorganisation](EU) Hubble Space Telescope.

    From Hubblesite

    June 16, 2022

    Infrared-Radio Image of the Large Magellanic Cloud
    1
    About This Image
    The Large Magellanic Cloud (LMC) is a satellite of the Milky Way, containing about 30 billion stars. Seen here in a far-infrared and radio view, the LMC’s cool and warm dust are shown in green and blue, respectively, with hydrogen gas in red. The image is composed of data from the European Space Agency (ESA) Herschel mission, supplemented with data from ESA’s retired Planck observatory and two retired NASA missions: the Infrared Astronomy Survey and Cosmic Background Explorer, as well as the Parkes, ATCA, and Mopra radio telescopes.


    Credits: IMAGE: Christopher Clark (STScI), S. Kim (Sejong University), T. Wong (UIUC)/ESA, NASA, NASA-JPL, Caltech.

    Infrared-Radio Image of the Small Magellanic Cloud
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    About This Image
    The Small Magellanic Cloud is a satellite of the Milky Way, containing about 3 billion stars. This far-infrared and radio view of it shows the cool (green) and warm (blue) dust, as well as the hydrogen gas (red). The image is composed of data from the European Space Agency (ESA) Herschel mission, supplemented with data from ESA’s retired Planck observatory and two retired NASA missions: the Infrared Astronomy Survey and Cosmic Background Explorer, as well as the Parkes, ATCA, and NANTEN radio telescopes.


    Credits: IMAGE: Christopher Clark (STScI), S. Stanimirovic (UW-Madison), N. Mizuno (Nagoya University)/ ESA, NASA, NASA-JPL, Caltech.

    Infrared-Radio Image of the Andromeda Galaxy (Messier 31)
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    About This Image
    The Andromeda galaxy, or Messier 31, is shown here in far-infrared and radio wavelengths of light. Some of the hydrogen gas (red) that traces the edge of Andromeda’s disc was pulled in from intergalactic space, and some was torn away from galaxies that merged with Andromeda far in the past. The image is composed of data from the European Space Agency (ESA) Herschel mission, supplemented with data from ESA’s retired Planck observatory and two retired NASA missions: the Infrared Astronomy Survey and Cosmic Background Explorer, as well as the Green Bank Telescope, WRST, and IRAM radio telescopes.

    Credits: IMAGE: Christopher Clark (STScI), R. Braun (SKA Observatory), C. Nieten (MPI Radioastronomie), Matt Smith (Cardiff University)/ ESA, NASA, NASA-JPL, Caltech.

    Infrared-Radio Image of the Triangulum Galaxy (Messier 33)
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    About This Image
    The Triangulum galaxy, or Messier 33, is shown here in far-infrared and radio wavelengths of light. Some of the hydrogen gas (red) that traces the edge of the Triangulum’s disc was pulled in from intergalactic space, and some was torn away from galaxies that merged with Triangulum far in the past. The image is composed of data from the European Space Agency (ESA) Herschel mission, supplemented with data from ESA’s retired Planck observatory and two retired NASA missions: the Infrared Astronomy Survey and Cosmic Background Explorer, as well as the Very Large Array, Green Bank Telescope, and IRAM radio telescope.


    Credits: IMAGE: Christopher Clark (STScI), E. Koch (University of Alberta), C. Druard (University of Bordeaux)/ ESA, NASA, NASA-JPL, Caltech,

    Summary

    The stunning perspectives show four of our galactic neighbors in a different light.

    New images using data from European Space Agency (ESA) and NASA missions showcase the gas and dust that fill the space between stars in four of the galaxies closest to our own Milky Way. More than striking, the snapshots are also a scientific trove, lending insight into how dramatically the density of dust clouds can vary within a galaxy.
    _____________________________________________________
    New images using data from European Space Agency (ESA) and NASA missions showcase the gas and dust that fill the space between stars in four of the galaxies closest to our own Milky Way. More than striking, the snapshots are also a scientific trove, lending insight into how dramatically the density of dust clouds can vary within a galaxy.

    With a consistency similar to smoke, dust is created by dying stars and is one of the materials that forms new stars. The dust clouds observed by space telescopes are constantly shaped and molded by exploding stars, stellar winds, and the effects of gravity. Almost half of all the starlight in the universe is absorbed by dust. Many of the heavy chemical elements essential to forming planets like Earth are locked up in dust grains in interstellar space. Understanding dust is an essential part of understanding our universe.

    The observations were made possible through the work of ESA’s Herschel Space Observatory, which operated from 2009 to 2013. Herschel’s super-cold instruments were able to detect the thermal glow of dust, which is emitted as far-infrared light, a range of wavelengths longer than what human eyes can detect.

    Herschel’s images of interstellar dust provide high-resolution views of fine details in these clouds, revealing intricate substructures. But the way the space telescope was designed meant that it often couldn’t detect light from clouds that are more spread out and diffuse, especially in the outer regions of galaxies, where the gas and dust become sparse and thus fainter. For some nearby galaxies, that meant Herschel missed up to 30% of all the light given off by dust. With such a significant gap, astronomers struggled to use the Herschel data to understand how dust and gas behaved in these environments. To fill out the Herschel dust maps, the new images combine data from three other missions: ESA’s retired Planck observatory, along with two retired NASA missions, the Infrared Astronomical Satellite (IRAS) and Cosmic Background Explorer (COBE).

    The images show the Andromeda galaxy, also known as M31; the Triangulum galaxy, or M33; and the Large and Small Magellanic Clouds – dwarf galaxies orbiting the Milky Way that do not have the spiral structure of the Andromeda and Triangulum galaxies. All four are within 3 million light-years of Earth.

    In the images, red indicates hydrogen gas, the most common element in the universe. The image of the Large Magellanic Cloud shows a red tail coming off the bottom left of the galaxy that was likely created when it collided with the Small Magellanic Cloud about 100 million years ago. Bubbles of empty space indicate regions where stars have recently formed, because intense winds from the newborn stars blow away the surrounding dust and gas. The green light around the edges of those bubbles indicates the presence of cold dust that has piled up as a result of those winds. Warmer dust, shown in blue, indicates where stars are forming or other processes have heated the dust.

    Many heavy elements in nature – like carbon, oxygen, and iron – can get stuck to dust grains, and the presence of different elements changes the way dust absorbs starlight. This in turn affects the view astronomers get of events like star formation. In the densest dust clouds, almost all the heavy elements can get locked up in dust grains, which increases the dust-to-gas ratio. But in less dense regions, the destructive radiation from newborn stars or shockwaves from exploding stars will smash the dust grains and return some of those locked-up heavy elements back into the gas, changing the ratio once again. Scientists who study interstellar space and star formation want to better understand this ongoing cycle. The Herschel images show that the dust-to-gas ratio can vary within a single galaxy by up to a factor of 20, far more than previously estimated.

    “These improved Herschel images show us that the dust ‘ecosystems’ in these galaxies are very dynamic,” said Christopher Clark, an astronomer at the Space Science Telescope Institute in Baltimore, Maryland, who led the work to create the new images.

    These results were featured in a press conference at the summer meeting of the American Astronomical Society.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    The NASA/ESA Hubble Space Telescope is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA’s Great Observatories, along with the NASA Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the NASA Spitzer Infrared Space Telescope.

    National Aeronautics Space Agency Compton Gamma Ray Observatory
    National Aeronautics and Space Administration Chandra X-ray telescope.
    National Aeronautics and Space AdministrationSpitzer Infrared Apace Telescope no longer in service. Launched in 2003 and retired on 30 January 2020.

    Edwin Hubble at Caltech Palomar Samuel Oschin 48 inch Telescope Credit: Emilio Segre Visual Archives/AIP/SPL.

    Edwin Hubble looking through the 100-inch Hooker telescope at Mount Wilson in Southern California, 1929 discovers the Universe is Expanding. Credit: Margaret Bourke-White/Time & Life Pictures/Getty Images.

    Hubble features a 2.4-meter (7.9 ft) mirror, and its four main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble’s orbit outside the distortion of Earth’s atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detailed visible light images, allowing a deep view into space. Many Hubble observations have led to breakthroughs in astrophysics, such as determining the rate of expansion of the universe.

    The Hubble telescope was built by the United States space agency National Aeronautics Space Agency with contributions from the The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU). The Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, while the NASA Goddard Space Flight Center controls the spacecraft. Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster. It was finally launched by Space Shuttle Discovery in 1990, but its main mirror had been ground incorrectly, resulting in spherical aberration that compromised the telescope’s capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.

    Hubble is the only telescope designed to be maintained in space by astronauts. Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments. The fifth mission was initially canceled on safety grounds following the Columbia disaster (2003), but NASA administrator Michael D. Griffin approved the fifth servicing mission which was completed in 2009. The telescope was still operating as of April 24, 2020, its 30th anniversary, and could last until 2030–2040. One successor to the Hubble telescope is the National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne](EU)/Canadian Space Agency(CA) Webb Infrared Space Telescope.

    National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) Webb Infrared Space Telescope James Webb Space Telescope annotated . Launched December 25, 2021, ten years late.

    Proposals and precursors

    In 1923, Hermann Oberth—considered a father of modern rocketry, along with Robert H. Goddard and Konstantin Tsiolkovsky—published Die Rakete zu den Planetenräumen (“The Rocket into Planetary Space“), which mentioned how a telescope could be propelled into Earth orbit by a rocket.

    The history of the Hubble Space Telescope can be traced back as far as 1946, to astronomer Lyman Spitzer’s paper entitled Astronomical advantages of an extraterrestrial observatory. In it, he discussed the two main advantages that a space-based observatory would have over ground-based telescopes. First, the angular resolution (the smallest separation at which objects can be clearly distinguished) would be limited only by diffraction, rather than by the turbulence in the atmosphere, which causes stars to twinkle, known to astronomers as seeing. At that time ground-based telescopes were limited to resolutions of 0.5–1.0 arcseconds, compared to a theoretical diffraction-limited resolution of about 0.05 arcsec for an optical telescope with a mirror 2.5 m (8.2 ft) in diameter. Second, a space-based telescope could observe infrared and ultraviolet light, which are strongly absorbed by the atmosphere.

    Spitzer devoted much of his career to pushing for the development of a space telescope. In 1962, a report by the U.S. National Academy of Sciences recommended development of a space telescope as part of the space program, and in 1965 Spitzer was appointed as head of a committee given the task of defining scientific objectives for a large space telescope.

    Space-based astronomy had begun on a very small-scale following World War II, as scientists made use of developments that had taken place in rocket technology. The first ultraviolet spectrum of the Sun was obtained in 1946, and the National Aeronautics and Space Administration launched the Orbiting Solar Observatory (OSO) to obtain UV, X-ray, and gamma-ray spectra in 1962.
    National Aeronautics Space Agency Orbiting Solar Observatory

    An orbiting solar telescope was launched in 1962 by the United Kingdom as part of the Ariel space program, and in 1966 NASA launched the first Orbiting Astronomical Observatory (OAO) mission. OAO-1’s battery failed after three days, terminating the mission. It was followed by OAO-2, which carried out ultraviolet observations of stars and galaxies from its launch in 1968 until 1972, well beyond its original planned lifetime of one year.

    The OSO and OAO missions demonstrated the important role space-based observations could play in astronomy. In 1968, NASA developed firm plans for a space-based reflecting telescope with a mirror 3 m (9.8 ft) in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST), with a launch slated for 1979. These plans emphasized the need for crewed maintenance missions to the telescope to ensure such a costly program had a lengthy working life, and the concurrent development of plans for the reusable Space Shuttle indicated that the technology to allow this was soon to become available.

    Quest for funding

    The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for the telescope project.
    In response a nationwide lobbying effort was coordinated among astronomers. Many astronomers met congressmen and senators in person, and large-scale letter-writing campaigns were organized. The National Academy of Sciences published a report emphasizing the need for a space telescope, and eventually the Senate agreed to half the budget that had originally been approved by Congress.

    The funding issues led to something of a reduction in the scale of the project, with the proposed mirror diameter reduced from 3 m to 2.4 m, both to cut costs and to allow a more compact and effective configuration for the telescope hardware. A proposed precursor 1.5 m (4.9 ft) space telescope to test the systems to be used on the main satellite was dropped, and budgetary concerns also prompted collaboration with the European Space Agency. ESA agreed to provide funding and supply one of the first-generation instruments for the telescope, as well as the solar cells that would power it, and staff to work on the telescope in the United States, in return for European astronomers being guaranteed at least 15% of the observing time on the telescope. Congress eventually approved funding of US$36 million for 1978, and the design of the LST began in earnest, aiming for a launch date of 1983. In 1983 the telescope was named after Edwin Hubble, who confirmed one of the greatest scientific discoveries of the 20th century, made by Georges Lemaitre, that the universe is expanding.

    Construction and engineering

    Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions. NASA Marshall Space Flight Center was given responsibility for the design, development, and construction of the telescope, while Goddard Space Flight Center was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company Perkin-Elmer to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed.

    Optical Telescope Assembly

    Optically, the HST is a Cassegrain reflector of Ritchey–Chrétien design, as are most large professional telescopes. This design, with two hyperbolic mirrors, is known for good imaging performance over a wide field of view, with the disadvantage that the mirrors have shapes that are hard to fabricate and test. The mirror and optical systems of the telescope determine the final performance, and they were designed to exacting specifications. Optical telescopes typically have mirrors polished to an accuracy of about a tenth of the wavelength of visible light, but the Space Telescope was to be used for observations from the visible through the ultraviolet (shorter wavelengths) and was specified to be diffraction limited to take full advantage of the space environment. Therefore, its mirror needed to be polished to an accuracy of 10 nanometers, or about 1/65 of the wavelength of red light. On the long wavelength end, the OTA was not designed with optimum IR performance in mind—for example, the mirrors are kept at stable (and warm, about 15 °C) temperatures by heaters. This limits Hubble’s performance as an infrared telescope.

    Perkin-Elmer intended to use custom-built and extremely sophisticated computer-controlled polishing machines to grind the mirror to the required shape. However, in case their cutting-edge technology ran into difficulties, NASA demanded that PE sub-contract to Kodak to construct a back-up mirror using traditional mirror-polishing techniques. (The team of Kodak and Itek also bid on the original mirror polishing work. Their bid called for the two companies to double-check each other’s work, which would have almost certainly caught the polishing error that later caused such problems.) The Kodak mirror is now on permanent display at the National Air and Space Museum. An Itek mirror built as part of the effort is now used in the 2.4 m telescope at the Magdalena Ridge Observatory.

    Construction of the Perkin-Elmer mirror began in 1979, starting with a blank manufactured by Corning from their ultra-low expansion glass. To keep the mirror’s weight to a minimum it consisted of top and bottom plates, each one inch (25 mm) thick, sandwiching a honeycomb lattice. Perkin-Elmer simulated microgravity by supporting the mirror from the back with 130 rods that exerted varying amounts of force. This ensured the mirror’s final shape would be correct and to specification when finally deployed. Mirror polishing continued until May 1981. NASA reports at the time questioned Perkin-Elmer’s managerial structure, and the polishing began to slip behind schedule and over budget. To save money, NASA halted work on the back-up mirror and put the launch date of the telescope back to October 1984. The mirror was completed by the end of 1981; it was washed using 2,400 US gallons (9,100 L) of hot, deionized water and then received a reflective coating of 65 nm-thick aluminum and a protective coating of 25 nm-thick magnesium fluoride.

    Doubts continued to be expressed about Perkin-Elmer’s competence on a project of this importance, as their budget and timescale for producing the rest of the OTA continued to inflate. In response to a schedule described as “unsettled and changing daily”, NASA postponed the launch date of the telescope until April 1985. Perkin-Elmer’s schedules continued to slip at a rate of about one month per quarter, and at times delays reached one day for each day of work. NASA was forced to postpone the launch date until March and then September 1986. By this time, the total project budget had risen to US$1.175 billion.

    Spacecraft systems

    The spacecraft in which the telescope and instruments were to be housed was another major engineering challenge. It would have to withstand frequent passages from direct sunlight into the darkness of Earth’s shadow, which would cause major changes in temperature, while being stable enough to allow extremely accurate pointing of the telescope. A shroud of multi-layer insulation keeps the temperature within the telescope stable and surrounds a light aluminum shell in which the telescope and instruments sit. Within the shell, a graphite-epoxy frame keeps the working parts of the telescope firmly aligned. Because graphite composites are hygroscopic, there was a risk that water vapor absorbed by the truss while in Lockheed’s clean room would later be expressed in the vacuum of space; resulting in the telescope’s instruments being covered by ice. To reduce that risk, a nitrogen gas purge was performed before launching the telescope into space.

    While construction of the spacecraft in which the telescope and instruments would be housed proceeded somewhat more smoothly than the construction of the OTA, Lockheed still experienced some budget and schedule slippage, and by the summer of 1985, construction of the spacecraft was 30% over budget and three months behind schedule. An MSFC report said Lockheed tended to rely on NASA directions rather than take their own initiative in the construction.

    Computer systems and data processing

    The two initial, primary computers on the HST were the 1.25 MHz DF-224 system, built by Rockwell Autonetics, which contained three redundant CPUs, and two redundant NSSC-1 (NASA Standard Spacecraft Computer, Model 1) systems, developed by Westinghouse and GSFC using diode–transistor logic (DTL). A co-processor for the DF-224 was added during Servicing Mission 1 in 1993, which consisted of two redundant strings of an Intel-based 80386 processor with an 80387-math co-processor. The DF-224 and its 386 co-processor were replaced by a 25 MHz Intel-based 80486 processor system during Servicing Mission 3A in 1999. The new computer is 20 times faster, with six times more memory, than the DF-224 it replaced. It increases throughput by moving some computing tasks from the ground to the spacecraft and saves money by allowing the use of modern programming languages.

    Additionally, some of the science instruments and components had their own embedded microprocessor-based control systems. The MATs (Multiple Access Transponder) components, MAT-1 and MAT-2, utilize Hughes Aircraft CDP1802CD microprocessors. The Wide Field and Planetary Camera (WFPC) also utilized an RCA 1802 microprocessor (or possibly the older 1801 version). The WFPC-1 was replaced by the WFPC-2 [below] during Servicing Mission 1 in 1993, which was then replaced by the Wide Field Camera 3 (WFC3) [below] during Servicing Mission 4 in 2009.

    Initial instruments

    When launched, the HST carried five scientific instruments: the Wide Field and Planetary Camera (WF/PC), Goddard High Resolution Spectrograph (GHRS), High Speed Photometer (HSP), Faint Object Camera (FOC) and the Faint Object Spectrograph (FOS). WF/PC was a high-resolution imaging device primarily intended for optical observations. It was built by NASA JPL-Caltech, and incorporated a set of 48 filters isolating spectral lines of particular astrophysical interest. The instrument contained eight charge-coupled device (CCD) chips divided between two cameras, each using four CCDs. Each CCD has a resolution of 0.64 megapixels. The wide field camera (WFC) covered a large angular field at the expense of resolution, while the planetary camera (PC) took images at a longer effective focal length than the WF chips, giving it a greater magnification.

    The GHRS was a spectrograph designed to operate in the ultraviolet. It was built by the Goddard Space Flight Center and could achieve a spectral resolution of 90,000. Also optimized for ultraviolet observations were the FOC and FOS, which were capable of the highest spatial resolution of any instruments on Hubble. Rather than CCDs these three instruments used photon-counting digicons as their detectors. The FOC was constructed by ESA, while the University of California, San Diego, and Martin Marietta Corporation built the FOS.

    The final instrument was the HSP, designed and built at the University of Wisconsin–Madison. It was optimized for visible and ultraviolet light observations of variable stars and other astronomical objects varying in brightness. It could take up to 100,000 measurements per second with a photometric accuracy of about 2% or better.

    HST’s guidance system can also be used as a scientific instrument. Its three Fine Guidance Sensors (FGS) are primarily used to keep the telescope accurately pointed during an observation, but can also be used to carry out extremely accurate astrometry; measurements accurate to within 0.0003 arcseconds have been achieved.

    Ground support

    The Space Telescope Science Institute is responsible for the scientific operation of the telescope and the delivery of data products to astronomers. STScI is operated by the Association of Universities for Research in Astronomy and is physically located in Baltimore, Maryland on the Homewood campus of Johns Hopkins University, one of the 39 U.S. universities and seven international affiliates that make up the AURA consortium. STScI was established in 1981 after something of a power struggle between NASA and the scientific community at large. NASA had wanted to keep this function in-house, but scientists wanted it to be based in an academic establishment. The Space Telescope European Coordinating Facility, established at Garching bei München near Munich in 1984, provided similar support for European astronomers until 2011, when these activities were moved to the European Space Astronomy Centre.

    One rather complex task that falls to STScI is scheduling observations for the telescope. Hubble is in a low-Earth orbit to enable servicing missions, but this means most astronomical targets are occulted by the Earth for slightly less than half of each orbit. Observations cannot take place when the telescope passes through the South Atlantic Anomaly due to elevated radiation levels, and there are also sizable exclusion zones around the Sun (precluding observations of Mercury), Moon and Earth. The solar avoidance angle is about 50°, to keep sunlight from illuminating any part of the OTA. Earth and Moon avoidance keeps bright light out of the FGSs, and keeps scattered light from entering the instruments. If the FGSs are turned off, the Moon and Earth can be observed. Earth observations were used very early in the program to generate flat-fields for the WFPC1 instrument. There is a so-called continuous viewing zone (CVZ), at roughly 90° to the plane of Hubble’s orbit, in which targets are not occulted for long periods.

    Challenger disaster, delays, and eventual launch

    By January 1986, the planned launch date of October looked feasible, but the Challenger explosion brought the U.S. space program to a halt, grounding the Shuttle fleet and forcing the launch of Hubble to be postponed for several years. The telescope had to be kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. This costly situation (about US$6 million per month) pushed the overall costs of the project even higher. This delay did allow time for engineers to perform extensive tests, swap out a possibly failure-prone battery, and make other improvements. Furthermore, the ground software needed to control Hubble was not ready in 1986, and was barely ready by the 1990 launch.

    Eventually, following the resumption of shuttle flights in 1988, the launch of the telescope was scheduled for 1990. On April 24, 1990, Space Shuttle Discovery successfully launched it during the STS-31 mission.

    From its original total cost estimate of about US$400 million, the telescope cost about US$4.7 billion by the time of its launch. Hubble’s cumulative costs were estimated to be about US$10 billion in 2010, twenty years after launch.

    List of Hubble instruments

    Hubble accommodates five science instruments at a given time, plus the Fine Guidance Sensors, which are mainly used for aiming the telescope but are occasionally used for scientific astrometry measurements. Early instruments were replaced with more advanced ones during the Shuttle servicing missions. COSTAR was a corrective optics device rather than a science instrument, but occupied one of the five instrument bays.
    Since the final servicing mission in 2009, the four active instruments have been ACS, COS, STIS and WFC3. NICMOS is kept in hibernation, but may be revived if WFC3 were to fail in the future.

    Advanced Camera for Surveys (ACS; 2002–present)
    Cosmic Origins Spectrograph (COS; 2009–present)
    Corrective Optics Space Telescope Axial Replacement (COSTAR; 1993–2009)
    Faint Object Camera (FOC; 1990–2002)
    Faint Object Spectrograph (FOS; 1990–1997)
    Fine Guidance Sensor (FGS; 1990–present)
    Goddard High Resolution Spectrograph (GHRS/HRS; 1990–1997)
    High Speed Photometer (HSP; 1990–1993)
    Near Infrared Camera and Multi-Object Spectrometer (NICMOS; 1997–present, hibernating since 2008)
    Space Telescope Imaging Spectrograph (STIS; 1997–present (non-operative 2004–2009))
    Wide Field and Planetary Camera (WFPC; 1990–1993)
    Wide Field and Planetary Camera 2 (WFPC2; 1993–2009)
    Wide Field Camera 3 (WFC3; 2009–present)

    Of the former instruments, three (COSTAR, FOS and WFPC2) are displayed in the Smithsonian National Air and Space Museum. The FOC is in the Dornier Museum, Germany. The HSP is in the Space Place at the University of Wisconsin–Madison. The first WFPC was dismantled, and some components were then re-used in WFC3.

    Flawed mirror

    Within weeks of the launch of the telescope, the returned images indicated a serious problem with the optical system. Although the first images appeared to be sharper than those of ground-based telescopes, Hubble failed to achieve a final sharp focus and the best image quality obtained was drastically lower than expected. Images of point sources spread out over a radius of more than one arcsecond, instead of having a point spread function (PSF) concentrated within a circle 0.1 arcseconds (485 nrad) in diameter, as had been specified in the design criteria.

    Analysis of the flawed images revealed that the primary mirror had been polished to the wrong shape. Although it was believed to be one of the most precisely figured optical mirrors ever made, smooth to about 10 nanometers, the outer perimeter was too flat by about 2200 nanometers (about 1⁄450 mm or 1⁄11000 inch). This difference was catastrophic, introducing severe spherical aberration, a flaw in which light reflecting off the edge of a mirror focuses on a different point from the light reflecting off its center.

    The effect of the mirror flaw on scientific observations depended on the particular observation—the core of the aberrated PSF was sharp enough to permit high-resolution observations of bright objects, and spectroscopy of point sources was affected only through a sensitivity loss. However, the loss of light to the large, out-of-focus halo severely reduced the usefulness of the telescope for faint objects or high-contrast imaging. This meant nearly all the cosmological programs were essentially impossible, since they required observation of exceptionally faint objects. This led politicians to question NASA’s competence, scientists to rue the cost which could have gone to more productive endeavors, and comedians to make jokes about NASA and the telescope − in the 1991 comedy The Naked Gun 2½: The Smell of Fear, in a scene where historical disasters are displayed, Hubble is pictured with RMS Titanic and LZ 129 Hindenburg. Nonetheless, during the first three years of the Hubble mission, before the optical corrections, the telescope still carried out a large number of productive observations of less demanding targets. The error was well characterized and stable, enabling astronomers to partially compensate for the defective mirror by using sophisticated image processing techniques such as deconvolution.

    Origin of the problem

    A commission headed by Lew Allen, director of the Jet Propulsion Laboratory, was established to determine how the error could have arisen. The Allen Commission found that a reflective null corrector, a testing device used to achieve a properly shaped non-spherical mirror, had been incorrectly assembled—one lens was out of position by 1.3 mm (0.051 in). During the initial grinding and polishing of the mirror, Perkin-Elmer analyzed its surface with two conventional refractive null correctors. However, for the final manufacturing step (figuring), they switched to the custom-built reflective null corrector, designed explicitly to meet very strict tolerances. The incorrect assembly of this device resulted in the mirror being ground very precisely but to the wrong shape. A few final tests, using the conventional null correctors, correctly reported spherical aberration. But these results were dismissed, thus missing the opportunity to catch the error, because the reflective null corrector was considered more accurate.

    The commission blamed the failings primarily on Perkin-Elmer. Relations between NASA and the optics company had been severely strained during the telescope construction, due to frequent schedule slippage and cost overruns. NASA found that Perkin-Elmer did not review or supervise the mirror construction adequately, did not assign its best optical scientists to the project (as it had for the prototype), and in particular did not involve the optical designers in the construction and verification of the mirror. While the commission heavily criticized Perkin-Elmer for these managerial failings, NASA was also criticized for not picking up on the quality control shortcomings, such as relying totally on test results from a single instrument.

    Design of a solution

    Many feared that Hubble would be abandoned. The design of the telescope had always incorporated servicing missions, and astronomers immediately began to seek potential solutions to the problem that could be applied at the first servicing mission, scheduled for 1993. While Kodak had ground a back-up mirror for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope back to Earth for a refit. Instead, the fact that the mirror had been ground so precisely to the wrong shape led to the design of new optical components with exactly the same error but in the opposite sense, to be added to the telescope at the servicing mission, effectively acting as “spectacles” to correct the spherical aberration.

    The first step was a precise characterization of the error in the main mirror. Working backwards from images of point sources, astronomers determined that the conic constant of the mirror as built was −1.01390±0.0002, instead of the intended −1.00230. The same number was also derived by analyzing the null corrector used by Perkin-Elmer to figure the mirror, as well as by analyzing interferograms obtained during ground testing of the mirror.

    Because of the way the HST’s instruments were designed, two different sets of correctors were required. The design of the Wide Field and Planetary Camera 2, already planned to replace the existing WF/PC, included relay mirrors to direct light onto the four separate charge-coupled device (CCD) chips making up its two cameras. An inverse error built into their surfaces could completely cancel the aberration of the primary. However, the other instruments lacked any intermediate surfaces that could be figured in this way, and so required an external correction device.

    The Corrective Optics Space Telescope Axial Replacement (COSTAR) system was designed to correct the spherical aberration for light focused at the FOC, FOS, and GHRS. It consists of two mirrors in the light path with one ground to correct the aberration. To fit the COSTAR system onto the telescope, one of the other instruments had to be removed, and astronomers selected the High Speed Photometer to be sacrificed. By 2002, all the original instruments requiring COSTAR had been replaced by instruments with their own corrective optics. COSTAR was removed and returned to Earth in 2009 where it is exhibited at the National Air and Space Museum. The area previously used by COSTAR is now occupied by the Cosmic Origins Spectrograph.

    NASA COSTAR

    NASA COSTAR installation

    Servicing missions and new instruments

    Servicing Mission 1

    The first Hubble serving mission was scheduled for 1993 before the mirror problem was discovered. It assumed greater importance, as the astronauts would need to do extensive work to install corrective optics; failure would have resulted in either abandoning Hubble or accepting its permanent disability. Other components failed before the mission, causing the repair cost to rise to $500 million (not including the cost of the shuttle flight). A successful repair would help demonstrate the viability of building Space Station Alpha, however.

    STS-49 in 1992 demonstrated the difficulty of space work. While its rescue of Intelsat 603 received praise, the astronauts had taken possibly reckless risks in doing so. Neither the rescue nor the unrelated assembly of prototype space station components occurred as the astronauts had trained, causing NASA to reassess planning and training, including for the Hubble repair. The agency assigned to the mission Story Musgrave—who had worked on satellite repair procedures since 1976—and six other experienced astronauts, including two from STS-49. The first mission director since Project Apollo would coordinate a crew with 16 previous shuttle flights. The astronauts were trained to use about a hundred specialized tools.

    Heat had been the problem on prior spacewalks, which occurred in sunlight. Hubble needed to be repaired out of sunlight. Musgrave discovered during vacuum training, seven months before the mission, that spacesuit gloves did not sufficiently protect against the cold of space. After STS-57 confirmed the issue in orbit, NASA quickly changed equipment, procedures, and flight plan. Seven total mission simulations occurred before launch, the most thorough preparation in shuttle history. No complete Hubble mockup existed, so the astronauts studied many separate models (including one at the Smithsonian) and mentally combined their varying and contradictory details. Service Mission 1 flew aboard Endeavour in December 1993, and involved installation of several instruments and other equipment over ten days.

    Most importantly, the High-Speed Photometer was replaced with the COSTAR corrective optics package, and WFPC was replaced with the Wide Field and Planetary Camera 2 (WFPC2) with an internal optical correction system. The solar arrays and their drive electronics were also replaced, as well as four gyroscopes in the telescope pointing system, two electrical control units and other electrical components, and two magnetometers. The onboard computers were upgraded with added coprocessors, and Hubble’s orbit was boosted.

    On January 13, 1994, NASA declared the mission a complete success and showed the first sharper images. The mission was one of the most complex performed up until that date, involving five long extra-vehicular activity periods. Its success was a boon for NASA, as well as for the astronomers who now had a more capable space telescope.

    Servicing Mission 2

    Servicing Mission 2, flown by Discovery in February 1997, replaced the GHRS and the FOS with the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), replaced an Engineering and Science Tape Recorder with a new Solid State Recorder, and repaired thermal insulation. NICMOS contained a heat sink of solid nitrogen to reduce the thermal noise from the instrument, but shortly after it was installed, an unexpected thermal expansion resulted in part of the heat sink coming into contact with an optical baffle. This led to an increased warming rate for the instrument and reduced its original expected lifetime of 4.5 years to about two years.

    Servicing Mission 3A

    Servicing Mission 3A, flown by Discovery, took place in December 1999, and was a split-off from Servicing Mission 3 after three of the six onboard gyroscopes had failed. The fourth failed a few weeks before the mission, rendering the telescope incapable of performing scientific observations. The mission replaced all six gyroscopes, replaced a Fine Guidance Sensor and the computer, installed a Voltage/temperature Improvement Kit (VIK) to prevent battery overcharging, and replaced thermal insulation blankets.

    Servicing Mission 3B

    Servicing Mission 3B flown by Columbia in March 2002 saw the installation of a new instrument, with the FOC (which, except for the Fine Guidance Sensors when used for astrometry, was the last of the original instruments) being replaced by the Advanced Camera for Surveys (ACS). This meant COSTAR was no longer required, since all new instruments had built-in correction for the main mirror aberration. The mission also revived NICMOS by installing a closed-cycle cooler and replaced the solar arrays for the second time, providing 30 percent more power.

    Servicing Mission 4

    Plans called for Hubble to be serviced in February 2005, but the Columbia disaster in 2003, in which the orbiter disintegrated on re-entry into the atmosphere, had wide-ranging effects on the Hubble program. NASA Administrator Sean O’Keefe decided all future shuttle missions had to be able to reach the safe haven of the International Space Station should in-flight problems develop. As no shuttles were capable of reaching both HST and the space station during the same mission, future crewed service missions were canceled. This decision was criticized by numerous astronomers who felt Hubble was valuable enough to merit the human risk. HST’s planned successor, the James Webb Telescope (JWST), as of 2004 was not expected to launch until at least 2011. A gap in space-observing capabilities between a decommissioning of Hubble and the commissioning of a successor was of major concern to many astronomers, given the significant scientific impact of HST. The consideration that JWST will not be located in low Earth orbit, and therefore cannot be easily upgraded or repaired in the event of an early failure, only made concerns more acute. On the other hand, many astronomers felt strongly that servicing Hubble should not take place if the expense were to come from the JWST budget.

    In January 2004, O’Keefe said he would review his decision to cancel the final servicing mission to HST, due to public outcry and requests from Congress for NASA to look for a way to save it. The National Academy of Sciences convened an official panel, which recommended in July 2004 that the HST should be preserved despite the apparent risks. Their report urged “NASA should take no actions that would preclude a space shuttle servicing mission to the Hubble Space Telescope”. In August 2004, O’Keefe asked Goddard Space Flight Center to prepare a detailed proposal for a robotic service mission. These plans were later canceled, the robotic mission being described as “not feasible”. In late 2004, several Congressional members, led by Senator Barbara Mikulski, held public hearings and carried on a fight with much public support (including thousands of letters from school children across the U.S.) to get the Bush Administration and NASA to reconsider the decision to drop plans for a Hubble rescue mission.

    The nomination in April 2005 of a new NASA Administrator, Michael D. Griffin, changed the situation, as Griffin stated he would consider a crewed servicing mission. Soon after his appointment Griffin authorized Goddard to proceed with preparations for a crewed Hubble maintenance flight, saying he would make the final decision after the next two shuttle missions. In October 2006 Griffin gave the final go-ahead, and the 11-day mission by Atlantis was scheduled for October 2008. Hubble’s main data-handling unit failed in September 2008, halting all reporting of scientific data until its back-up was brought online on October 25, 2008. Since a failure of the backup unit would leave the HST helpless, the service mission was postponed to incorporate a replacement for the primary unit.

    Servicing Mission 4 (SM4), flown by Atlantis in May 2009, was the last scheduled shuttle mission for HST. SM4 installed the replacement data-handling unit, repaired the ACS and STIS systems, installed improved nickel hydrogen batteries, and replaced other components including all six gyroscopes. SM4 also installed two new observation instruments—Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS)—and the Soft Capture and Rendezvous System, which will enable the future rendezvous, capture, and safe disposal of Hubble by either a crewed or robotic mission. Except for the ACS’s High Resolution Channel, which could not be repaired and was disabled, the work accomplished during SM4 rendered the telescope fully functional.

    Major projects

    Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey [CANDELS]

    The survey “aims to explore galactic evolution in the early Universe, and the very first seeds of cosmic structure at less than one billion years after the Big Bang.” The CANDELS project site describes the survey’s goals as the following:

    The Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey is designed to document the first third of galactic evolution from z = 8 to 1.5 via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS. It will also find the first Type Ia SNe beyond z > 1.5 and establish their accuracy as standard candles for cosmology. Five premier multi-wavelength sky regions are selected; each has multi-wavelength data from Spitzer and other facilities, and has extensive spectroscopy of the brighter galaxies. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to 109 solar masses out to z ~ 8.

    Frontier Fields program

    The program, officially named Hubble Deep Fields Initiative 2012, is aimed to advance the knowledge of early galaxy formation by studying high-redshift galaxies in blank fields with the help of gravitational lensing to see the “faintest galaxies in the distant universe”. The Frontier Fields web page describes the goals of the program being:

    To reveal hitherto inaccessible populations of z = 5–10 galaxies that are ten to fifty times fainter intrinsically than any presently known
    To solidify our understanding of the stellar masses and star formation histories of sub-L* galaxies at the earliest times
    To provide the first statistically meaningful morphological characterization of star forming galaxies at z > 5
    To find z > 8 galaxies stretched out enough by cluster lensing to discern internal structure and/or magnified enough by cluster lensing for spectroscopic follow-up.

    Cosmic Evolution Survey (COSMOS)

    The Cosmic Evolution Survey (COSMOS) is an astronomical survey designed to probe the formation and evolution of galaxies as a function of both cosmic time (redshift) and the local galaxy environment. The survey covers a two square degree equatorial field with spectroscopy and X-ray to radio imaging by most of the major space-based telescopes and a number of large ground based telescopes, making it a key focus region of extragalactic astrophysics. COSMOS was launched in 2006 as the largest project pursued by the Hubble Space Telescope at the time, and still is the largest continuous area of sky covered for the purposes of mapping deep space in blank fields, 2.5 times the area of the moon on the sky and 17 times larger than the largest of the CANDELS regions. The COSMOS scientific collaboration that was forged from the initial COSMOS survey is the largest and longest-running extragalactic collaboration, known for its collegiality and openness. The study of galaxies in their environment can be done only with large areas of the sky, larger than a half square degree. More than two million galaxies are detected, spanning 90% of the age of the Universe. The COSMOS collaboration is led by Caitlin Casey, Jeyhan Kartaltepe, and Vernesa Smolcic and involves more than 200 scientists in a dozen countries.

    Important discoveries

    Hubble has helped resolve some long-standing problems in astronomy, while also raising new questions. Some results have required new theories to explain them.

    Age of the universe

    Among its primary mission targets was to measure distances to Cepheid variable stars more accurately than ever before, and thus constrain the value of the Hubble constant, the measure of the rate at which the universe is expanding, which is also related to its age. Before the launch of HST, estimates of the Hubble constant typically had errors of up to 50%, but Hubble measurements of Cepheid variables in the Virgo Cluster and other distant galaxy clusters provided a measured value with an accuracy of ±10%, which is consistent with other more accurate measurements made since Hubble’s launch using other techniques. The estimated age is now about 13.7 billion years, but before the Hubble Telescope, scientists predicted an age ranging from 10 to 20 billion years.

    Expansion of the universe

    While Hubble helped to refine estimates of the age of the universe, it also cast doubt on theories about its future. Astronomers from the High-z Supernova Search Team and the Supernova Cosmology Project used ground-based telescopes and HST to observe distant supernovae and uncovered evidence that, far from decelerating under the influence of gravity, the expansion of the universe may in fact be accelerating. Three members of these two groups have subsequently been awarded Nobel Prizes for their discovery.

    Saul Perlmutter [The Supernova Cosmology Project] shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess [The High-z Supernova Search Team] for providing evidence that the expansion of the universe is accelerating.

    The cause of this acceleration remains poorly understood; the most common cause attributed is Dark Energy.

    Black holes

    The high-resolution spectra and images provided by the HST have been especially well-suited to establishing the prevalence of black holes in the center of nearby galaxies. While it had been hypothesized in the early 1960s that black holes would be found at the centers of some galaxies, and astronomers in the 1980s identified a number of good black hole candidates, work conducted with Hubble shows that black holes are probably common to the centers of all galaxies. The Hubble programs further established that the masses of the nuclear black holes and properties of the galaxies are closely related. The legacy of the Hubble programs on black holes in galaxies is thus to demonstrate a deep connection between galaxies and their central black holes.

    Extending visible wavelength images

    A unique window on the Universe enabled by Hubble are the Hubble Deep Field, Hubble Ultra-Deep Field, and Hubble Extreme Deep Field images, which used Hubble’s unmatched sensitivity at visible wavelengths to create images of small patches of sky that are the deepest ever obtained at optical wavelengths. The images reveal galaxies billions of light years away, and have generated a wealth of scientific papers, providing a new window on the early Universe. The Wide Field Camera 3 improved the view of these fields in the infrared and ultraviolet, supporting the discovery of some of the most distant objects yet discovered, such as MACS0647-JD.

    The non-standard object SCP 06F6 was discovered by the Hubble Space Telescope in February 2006.

    On March 3, 2016, researchers using Hubble data announced the discovery of the farthest known galaxy to date: GN-z11. The Hubble observations occurred on February 11, 2015, and April 3, 2015, as part of the CANDELS/GOODS-North surveys.

    Solar System discoveries

    HST has also been used to study objects in the outer reaches of the Solar System, including the dwarf planets Pluto and Eris.

    The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 was fortuitously timed for astronomers, coming just a few months after Servicing Mission 1 had restored Hubble’s optical performance. Hubble images of the planet were sharper than any taken since the passage of Voyager 2 in 1979, and were crucial in studying the dynamics of the collision of a comet with Jupiter, an event believed to occur once every few centuries.

    During June and July 2012, U.S. astronomers using Hubble discovered Styx, a tiny fifth moon orbiting Pluto.

    In March 2015, researchers announced that measurements of aurorae around Ganymede, one of Jupiter’s moons, revealed that it has a subsurface ocean. Using Hubble to study the motion of its aurorae, the researchers determined that a large saltwater ocean was helping to suppress the interaction between Jupiter’s magnetic field and that of Ganymede. The ocean is estimated to be 100 km (60 mi) deep, trapped beneath a 150 km (90 mi) ice crust.

    From June to August 2015, Hubble was used to search for a Kuiper belt object (KBO) target for the New Horizons Kuiper Belt Extended Mission (KEM) when similar searches with ground telescopes failed to find a suitable target.

    National Aeronautics Space Agency/New Horizons spacecraft.

    This resulted in the discovery of at least five new KBOs, including the eventual KEM target, 486958 Arrokoth, that New Horizons performed a close fly-by of on January 1, 2019.

    In August 2020, taking advantage of a total lunar eclipse, astronomers using NASA’s Hubble Space Telescope have detected Earth’s own brand of sunscreen – ozone – in our atmosphere. This method simulates how astronomers and astrobiology researchers will search for evidence of life beyond Earth by observing potential “biosignatures” on exoplanets (planets around other stars).
    Hubble and ALMA image of MACS J1149.5+2223.

    Supernova reappearance

    On December 11, 2015, Hubble captured an image of the first-ever predicted reappearance of a supernova, dubbed “Refsdal”, which was calculated using different mass models of a galaxy cluster whose gravity is warping the supernova’s light. The supernova was previously seen in November 2014 behind galaxy cluster MACS J1149.5+2223 as part of Hubble’s Frontier Fields program. Astronomers spotted four separate images of the supernova in an arrangement known as an “Einstein Cross”.

    The light from the cluster has taken about five billion years to reach Earth, though the supernova exploded some 10 billion years ago. Based on early lens models, a fifth image was predicted to reappear by the end of 2015. The detection of Refsdal’s reappearance in December 2015 served as a unique opportunity for astronomers to test their models of how mass, especially dark matter, is distributed within this galaxy cluster.

    Impact on astronomy

    Many objective measures show the positive impact of Hubble data on astronomy. Over 15,000 papers based on Hubble data have been published in peer-reviewed journals, and countless more have appeared in conference proceedings. Looking at papers several years after their publication, about one-third of all astronomy papers have no citations, while only two percent of papers based on Hubble data have no citations. On average, a paper based on Hubble data receives about twice as many citations as papers based on non-Hubble data. Of the 200 papers published each year that receive the most citations, about 10% are based on Hubble data.

    Although the HST has clearly helped astronomical research, its financial cost has been large. A study on the relative astronomical benefits of different sizes of telescopes found that while papers based on HST data generate 15 times as many citations as a 4 m (13 ft) ground-based telescope such as the William Herschel Telescope, the HST costs about 100 times as much to build and maintain.

    Isaac Newton Group 4.2 meter William Herschel Telescope at Roque de los Muchachos Observatory | Instituto de Astrofísica de Canarias • IAC(ES) on La Palma in the Canary Islands(ES), 2,396 m (7,861 ft)

    Deciding between building ground- versus space-based telescopes is complex. Even before Hubble was launched, specialized ground-based techniques such as aperture masking interferometry had obtained higher-resolution optical and infrared images than Hubble would achieve, though restricted to targets about 108 times brighter than the faintest targets observed by Hubble. Since then, advances in “adaptive optics” have extended the high-resolution imaging capabilities of ground-based telescopes to the infrared imaging of faint objects.

    Glistening against the awesome backdrop of the night sky above ESO’s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT, a major asset of the Adaptive Optics system.

    UCO KeckLaser Guide Star Adaptive Optics on two 10 meter Keck Observatory telescopes, Maunakea Hawaii, altitude 4,207 m (13,802 ft).

    The usefulness of adaptive optics versus HST observations depends strongly on the particular details of the research questions being asked. In the visible bands, adaptive optics can correct only a relatively small field of view, whereas HST can conduct high-resolution optical imaging over a wide field. Only a small fraction of astronomical objects are accessible to high-resolution ground-based imaging; in contrast Hubble can perform high-resolution observations of any part of the night sky, and on objects that are extremely faint.

    Impact on aerospace engineering

    In addition to its scientific results, Hubble has also made significant contributions to aerospace engineering, in particular the performance of systems in low Earth orbit. These insights result from Hubble’s long lifetime on orbit, extensive instrumentation, and return of assemblies to the Earth where they can be studied in detail. In particular, Hubble has contributed to studies of the behavior of graphite composite structures in vacuum, optical contamination from residual gas and human servicing, radiation damage to electronics and sensors, and the long-term behavior of multi-layer insulation. One lesson learned was that gyroscopes assembled using pressurized oxygen to deliver suspension fluid were prone to failure due to electric wire corrosion. Gyroscopes are now assembled using pressurized nitrogen. Another is that optical surfaces in LEO can have surprisingly long lifetimes; Hubble was only expected to last 15 years before the mirror became unusable, but after 14 years there was no measurable degradation. Finally, Hubble servicing missions, particularly those that serviced components not designed for in-space maintenance, have contributed towards the development of new tools and techniques for on-orbit repair.

    Archives

    All Hubble data is eventually made available via the Mikulski Archive for Space Telescopes at STScI, CADC and ESA/ESAC. Data is usually proprietary—available only to the principal investigator (PI) and astronomers designated by the PI—for twelve months after being taken. The PI can apply to the director of the STScI to extend or reduce the proprietary period in some circumstances.

    Observations made on Director’s Discretionary Time are exempt from the proprietary period, and are released to the public immediately. Calibration data such as flat fields and dark frames are also publicly available straight away. All data in the archive is in the FITS format, which is suitable for astronomical analysis but not for public use. The Hubble Heritage Project processes and releases to the public a small selection of the most striking images in JPEG and TIFF formats.

    Outreach activities

    It has always been important for the Space Telescope to capture the public’s imagination, given the considerable contribution of taxpayers to its construction and operational costs. After the difficult early years when the faulty mirror severely dented Hubble’s reputation with the public, the first servicing mission allowed its rehabilitation as the corrected optics produced numerous remarkable images.

    Several initiatives have helped to keep the public informed about Hubble activities. In the United States, outreach efforts are coordinated by the Space Telescope Science Institute (STScI) Office for Public Outreach, which was established in 2000 to ensure that U.S. taxpayers saw the benefits of their investment in the space telescope program. To that end, STScI operates the HubbleSite.org website. The Hubble Heritage Project, operating out of the STScI, provides the public with high-quality images of the most interesting and striking objects observed. The Heritage team is composed of amateur and professional astronomers, as well as people with backgrounds outside astronomy, and emphasizes the aesthetic nature of Hubble images. The Heritage Project is granted a small amount of time to observe objects which, for scientific reasons, may not have images taken at enough wavelengths to construct a full-color image.

    Since 1999, the leading Hubble outreach group in Europe has been the Hubble European Space Agency Information Centre (HEIC). This office was established at the Space Telescope European Coordinating Facility in Munich, Germany. HEIC’s mission is to fulfill HST outreach and education tasks for the European Space Agency. The work is centered on the production of news and photo releases that highlight interesting Hubble results and images. These are often European in origin, and so increase awareness of both ESA’s Hubble share (15%) and the contribution of European scientists to the observatory. ESA produces educational material, including a videocast series called Hubblecast designed to share world-class scientific news with the public.

    The Hubble Space Telescope has won two Space Achievement Awards from the Space Foundation, for its outreach activities, in 2001 and 2010.

    A replica of the Hubble Space Telescope is on the courthouse lawn in Marshfield, Missouri, the hometown of namesake Edwin P. Hubble.

    Major Instrumentation

    Hubble WFPC2 no longer in service.

    Wide Field Camera 3 [WFC3]

    National Aeronautics Space Agency/The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Hubble Wide Field Camera 3

    Advanced Camera for Surveys [ACS]

    National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU) NASA/ESA Hubble Space Telescope Advanced Camera for Surveys

    Cosmic Origins Spectrograph [COS]

    National Aeronautics Space Agency Cosmic Origins Spectrograph.

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy for NASA, conducts Hubble science operations.

    ESA50 Logo large

    The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [NASA/ESA Hubble, NASA Chandra, NASA Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 11:21 am on June 16, 2022 Permalink | Reply
    Tags: "The quiet life of Messier 94", Astronomers use a galaxy’s stellar halo as a “fossil record” to study these bulges., Ground based Optical Astronomy, Scientists are doing extragalactic archaeology in the stellar halo around Messier 94., Stars within classical bulges move a bit randomly-resembling elliptical galaxies-and seem to be older than their galaxy., Stars within pseudobulges move by rotation-like spiral galaxies-and don’t differ in age from their galaxy., Stellar halos can-for example-tell astronomers whether a galaxy has merged with another galaxy in its past., The scientists found no evidence of a massive merger in the Messier 94's history., The scientists looked at a type of star called a red-giant branch star-or an RGB star., The scientists used the Subaru data to catalog stars in Messier 94’s stellar halo according to their brightness., The stellar halo extends far beyond what a galaxy appears to be at first glance., , Tightly packed stars of a similar age within the center of a galaxy have a collective name: a bulge.   

    From The University of Michigan: “The quiet life of Messier 94” 

    U Michigan bloc

    From The University of Michigan

    June 14, 2022

    Contact:
    Morgan Sherburne

    1
    Messier 94 is a spiral galaxy located 16 million light-years away in the constellation Canes Venatici. University of Michigan doctoral student Katya Gozman investigated the galaxy’s halo to examine the galaxy’s merger history. Image credits: NASA ESA Hubble.

    Just like a murder of crows, a shrewdness of apes and a murmuration of starlings, tightly packed stars of a similar age within the center of a galaxy have a collective name: a bulge.

    Most galaxies have bulges at their centers. Depending on their properties—specifically, the kinematics of their stars—the bulges have different names. Stars within classical bulges move a bit randomly-resembling elliptical galaxies-and seem to be older than their galaxy, while stars within pseudobulges move by rotation-like spiral galaxies-and don’t differ in age from their galaxy.

    Astronomers use a galaxy’s stellar halo as a “fossil record” to study these bulges.

    Stellar halos can-for example-tell astronomers whether a galaxy has merged with another galaxy in its past.

    A University of Michigan doctoral student has examined the pseudobulge of the nearby disk galaxy Messier 94 and has found that despite the galaxy having the largest pseudobulge in the local universe, likely no massive galaxies crashed into Messier 94 in the past.

    “Astronomers believe that when a galaxy merges with another galaxy, the merger will deposit material into the stellar halo of the galaxy it merged with,” said lead author Katya Gozman. “By investigating and learning about the stars and stellar populations in the stellar halo, we can study and find out information about the past mergers a galaxy had. You could say we’re doing extragalactic archaeology in the stellar halo around Messier 94.”

    But Gozman and her co-authors found no evidence of a massive merger in the galaxy’s history. Instead, a smaller merger likely happened, with a galaxy the size of the Small Magellanic Cloud—a dwarf galaxy approximately three times smaller than the Milky Way—crashing into Messier 94.

    Gozman used observational data generated by the Subaru Hyper Suprime-Cam, located in Hawaii, to look at Messier 94’s stellar halo, the diffuse halo of stars that surrounds a galaxy.

    The stellar halo extends far beyond what a galaxy appears to be at first glance, and astronomers can examine this halo to look for remnants of past mergers. One way of learning about these remnants is to calculate the mass of a galaxy’s halo.

    2
    University of Michigan doctoral student Katya Gozman used images from the Subaru Suprime-Cam, a massive digital camera mounted to the Subaru Telescope in Hawaii, to study the merger history of galaxy M94. Image credit: Subaru Telescope, National Astronomical Observatory of Japan.

    For this study, Gozman used the Subaru data to catalog stars in Messier 94’s stellar halo according to their brightness. She plotted stars in what’s called a color magnitude diagram, which organizes stars according to their brightness as seen through certain filters used in astronomy to determine how much light a star is emitting.

    Specifically she looked at a type of star called a red-giant branch star-or an RGB star. These stars are luminous—a benefit for imaging them, Gozman says—and how red or blue the star is strongly correlates with what kinds of heavier, metallic elements they contain.

    Gozman then divided the RGBs in the galaxy into two regions: RGBs whose light appeared more blue, and RGBs whose light appeared more red. The blue RGBs were metal poor while the red RGBs were more metal rich. She also plotted the stars’ distribution in the galaxy, determining that the red RGBs are concentrated in a ring around the center of the galaxy while the blue RGBs are dispersed around the outer parts of its halo.

    Focusing on the blue RGBs, Gozman divided the galaxy into circular annuli, or concentric rings overlying the disk like a bullseye. By calculating the surface brightness of the stars in each ring, she was able to determine the mass of the stellar halo—which was not at all massive. The halo’s mass lets us infer the mass of the galaxy that merged into it.

    “We use the mass of the halo to infer the mass of the galaxy that last crashed into the galaxy we’re examining,” Gozman said. “One might think that if a really large galaxy crashed into M94 a long time ago, that might have significantly altered the morphology, the components, of the galaxy and maybe that could have given rise to this really large pseudobulge in the center.”

    But there was no large merger, Gozman found. The largest galaxy that crashed into Messier 94 in the past was not massive at all. Instead, she says the pseudobulge likely formed just through the typical evolution of the galaxy.

    However, very few studies have mapped the size of galaxy halos in this way. Gozman’s work to resolve the stars in M94’s stellar halo provides more information for astronomers who study galaxy mergers and evolution.

    “This data is the first data we’ve ever had of the resolved stellar population of this galaxy. Resolving stars is a pretty hard thing to do, but it is one of the best ways you can actually look at the halos and learn about the merger history of the galaxy,” she said. “So this is another datapoint in a field of very few data points.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please support STEM education in your local school system

    Stem Education Coalition

    U MIchigan Campus

    The University of Michigan is a public research university located in Ann Arbor, Michigan, United States. Originally, founded in 1817 in Detroit as the Catholepistemiad, or University of Michigania, 20 years before the Michigan Territory officially became a state, the University of Michigan is the state’s oldest university. The university moved to Ann Arbor in 1837 onto 40 acres (16 ha) of what is now known as Central Campus. Since its establishment in Ann Arbor, the university campus has expanded to include more than 584 major buildings with a combined area of more than 34 million gross square feet (781 acres or 3.16 km²), and has two satellite campuses located in Flint and Dearborn. The University was one of the founding members of the Association of American Universities.

    Considered one of the foremost research universities in the United States, the university has very high research activity and its comprehensive graduate program offers doctoral degrees in the humanities, social sciences, and STEM fields (Science, Technology, Engineering and Mathematics) as well as professional degrees in business, medicine, law, pharmacy, nursing, social work and dentistry. Michigan’s body of living alumni (as of 2012) comprises more than 500,000. Besides academic life, Michigan’s athletic teams compete in Division I of the NCAA and are collectively known as the Wolverines. They are members of the Big Ten Conference.

    At over $12.4 billion in 2019, Michigan’s endowment is among the largest of any university. As of October 2019, 53 MacArthur “genius award” winners (29 alumni winners and 24 faculty winners), 26 Nobel Prize winners, six Turing Award winners, one Fields Medalist and one Mitchell Scholar have been affiliated with the university. Its alumni include eight heads of state or government, including President of the United States Gerald Ford; 38 cabinet-level officials; and 26 living billionaires. It also has many alumni who are Fulbright Scholars and MacArthur Fellows.

    Research

    Michigan is one of the founding members (in the year 1900) of the Association of American Universities. With over 6,200 faculty members, 73 of whom are members of the National Academy and 471 of whom hold an endowed chair in their discipline, the university manages one of the largest annual collegiate research budgets of any university in the United States. According to the National Science Foundation, Michigan spent $1.6 billion on research and development in 2018, ranking it 2nd in the nation. This figure totaled over $1 billion in 2009. The Medical School spent the most at over $445 million, while the College of Engineering was second at more than $160 million. U-M also has a technology transfer office, which is the university conduit between laboratory research and corporate commercialization interests.

    In 2009, the university signed an agreement to purchase a facility formerly owned by Pfizer. The acquisition includes over 170 acres (0.69 km^2) of property, and 30 major buildings comprising roughly 1,600,000 square feet (150,000 m^2) of wet laboratory space, and 400,000 square feet (37,000 m^2) of administrative space. At the time of the agreement, the university’s intentions for the space were not set, but the expectation was that the new space would allow the university to ramp up its research and ultimately employ in excess of 2,000 people.

    The university is also a major contributor to the medical field with the EKG and the gastroscope. The university’s 13,000-acre (53 km^2) biological station in the Northern Lower Peninsula of Michigan is one of only 47 Biosphere Reserves in the United States.

    In the mid-1960s U-M researchers worked with IBM to develop a new virtual memory architectural model that became part of IBM’s Model 360/67 mainframe computer (the 360/67 was initially dubbed the 360/65M where the “M” stood for Michigan). The Michigan Terminal System (MTS), an early time-sharing computer operating system developed at U-M, was the first system outside of IBM to use the 360/67’s virtual memory features.

    U-M is home to the National Election Studies and the University of Michigan Consumer Sentiment Index. The Correlates of War project, also located at U-M, is an accumulation of scientific knowledge about war. The university is also home to major research centers in optics, reconfigurable manufacturing systems, wireless integrated microsystems, and social sciences. The University of Michigan Transportation Research Institute and the Life Sciences Institute are located at the university. The Institute for Social Research (ISR), the nation’s longest-standing laboratory for interdisciplinary research in the social sciences, is home to the Survey Research Center, Research Center for Group Dynamics, Center for Political Studies, Population Studies Center, and Inter-Consortium for Political and Social Research. Undergraduate students are able to participate in various research projects through the Undergraduate Research Opportunity Program (UROP) as well as the UROP/Creative-Programs.

    The U-M library system comprises nineteen individual libraries with twenty-four separate collections—roughly 13.3 million volumes. U-M was the original home of the JSTOR database, which contains about 750,000 digitized pages from the entire pre-1990 backfile of ten journals of history and economics, and has initiated a book digitization program in collaboration with Google. The University of Michigan Press is also a part of the U-M library system.

    In the late 1960s U-M, together with Michigan State University and Wayne State University, founded the Merit Network, one of the first university computer networks. The Merit Network was then and remains today administratively hosted by U-M. Another major contribution took place in 1987 when a proposal submitted by the Merit Network together with its partners IBM, MCI, and the State of Michigan won a national competition to upgrade and expand the National Science Foundation Network (NSFNET) backbone from 56,000 to 1.5 million, and later to 45 million bits per second. In 2006, U-M joined with Michigan State University and Wayne State University to create the the University Research Corridor. This effort was undertaken to highlight the capabilities of the state’s three leading research institutions and drive the transformation of Michigan’s economy. The three universities are electronically interconnected via the Michigan LambdaRail (MiLR, pronounced ‘MY-lar’), a high-speed data network providing 10 Gbit/s connections between the three university campuses and other national and international network connection points in Chicago.

     
  • richardmitnick 4:48 pm on June 15, 2022 Permalink | Reply
    Tags: "Mysterious 'blue blobs' reveal a new kind of star system", , , , Ground based Optical Astronomy, , Most of the stars in each of the five systems are very blue and very young and contain very little atomic hydrogen gas., , The fact that the new stellar systems are abundant in metals hints at how they might have formed., , These stellar systems formed from gas that was stripped from a big galaxy because how metals are built up is by many repeated episodes of star formation and you only really get that in a big galaxy.   

    From The University of Arizona: “Mysterious ‘blue blobs’ reveal a new kind of star system” 

    From The University of Arizona

    6.15.22

    Media contact
    Mikayla Mace Kelley
    Science Writer, University Communications
    mikaylamace@arizona.edu
    520-621-1878

    Researcher contacts
    Michael Jones
    Steward Observatory
    jonesmg@email.arizona.edu
    520-621-2288

    David Sand
    Department of Astronomy
    dsand@as.arizona.edu
    520-621-2288

    The stellar structures are thought to be created when galaxies collide with hot gas in a process that could be likened to doing a belly flop in a swimming pool.

    1
    UArizona astronomers have identified a new class of star system. The collection of mostly young blue stars are seen here using the Hubble Space Telescope Advanced Camera for Surveys. Credit: Michael Jones.

    University of Arizona astronomers have identified five examples of a new class of stellar system. They’re not quite galaxies and only exist in isolation.

    The new stellar systems contain only young, blue stars, which are distributed in an irregular pattern and seem to exist in surprising isolation from any potential parent galaxy.

    The stellar systems – which astronomers say appear through a telescope as “blue blobs” and are about the size of tiny dwarf galaxies – are located within the relatively nearby Virgo galaxy cluster. The five systems are separated from any potential parent galaxies by over 300,000 light years in some cases, making it challenging to identify their origins.

    The astronomers found the new systems after another research group, led by the Netherlands Institute for Radio Astronomy’s Elizabeth Adams, compiled a catalog of nearby gas clouds, providing a list of potential sites of new galaxies. Once that catalog was published, several research groups, including one led by UArizona associate astronomy professor David Sand, started looking for stars that could be associated with those gas clouds.

    The gas clouds were thought to be associated with our own galaxy, and most of them probably are, but when the first collection of stars, called SECCO1, was discovered, astronomers realized that it was not near the Milky Way at all, but rather in the Virgo cluster, which is much farther away but still very nearby in the scale of the universe.

    SECCO1 was one of the very unusual “blue blobs,” said Michael Jones, a postdoctoral fellow in the UArizona Steward Observatory and lead author of a study [The Astrophysical Journal] that describes the new stellar systems. Jones presented the findings, which Sand co-authored, during the 240th American Astronomical Society meeting in Pasadena, California, Wednesday.

    “It’s a lesson in the unexpected,” Jones said. “When you’re looking for things, you’re not necessarily going to find the thing you’re looking for, but you might find something else very interesting.”

    The team obtained their observations from the Hubble Space Telescope, the Very Large Array telescope in New Mexico and the Very Large Telescope in Chile.

    Study co-author Michele Bellazzini, with the Istituto Nazionale di Astrofisica in Italy, led the analysis of the data from Very Large Telescope and has submitted a companion paper focusing on that data.

    Together, the team learned that most of the stars in each system are very blue and very young and that they contain very little atomic hydrogen gas. This is significant because star formation begins with atomic hydrogen gas, which eventually evolves into dense clouds of molecular hydrogen gas before forming into stars.

    “We observed that most of the systems lack atomic gas, but that doesn’t mean there isn’t molecular gas,” Jones said. “In fact, there must be some molecular gas because they are still forming stars. The existence of mostly young stars and little gas signals that these systems must have lost their gas recently.”

    The combination of blue stars and lack of gas was unexpected, as was a lack of older stars in the systems. Most galaxies have older stars, which astronomers refer to as being “red and dead.”

    “Stars that are born red are lower mass and therefore live longer than blue stars, which burn fast and die young, so old red stars are usually the last ones left living,” Jones said. “And they’re dead because they don’t have any more gas with which to form new stars. These blue stars are like an oasis in the desert, basically.”

    The fact that the new stellar systems are abundant in metals hints at how they might have formed.

    “To astronomers, metals are any element heavier than helium,” Jones said. “This tells us that these stellar systems formed from gas that was stripped from a big galaxy, because how metals are built up is by many repeated episodes of star formation, and you only really get that in a big galaxy.”

    There are two main ways gas can be stripped from a galaxy. The first is tidal stripping, which occurs when two big galaxies pass by each other and gravitationally tear away gas and stars.

    The other is what’s known as ram pressure stripping.

    “This is like if you belly flop into a swimming pool,” Jones said. “When a galaxy belly flops into a cluster that is full of hot gas, then its gas gets forced out behind it. That’s the mechanism that we think we’re seeing here to create these objects.”

    The team prefers the ram pressure stripping explanation because in order for the blue blobs to have become as isolated as they are, they must have been moving very quickly, and the speed of tidal stripping is low compared to ram pressure stripping.

    Astronomers expect that one day these systems will eventually split off into individual clusters of stars and spread out across the larger galaxy cluster.

    What researchers have learned feeds into the larger “story of recycling of gas and stars in the universe,” Sand said. “We think that this belly flopping process changes a lot of spiral galaxies into elliptical galaxies on some level, so learning more about the general process teaches us more about galaxy formation.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    As of 2019, the The University of Arizona enrolled 45,918 students in 19 separate colleges/schools, including The University of Arizona College of Medicine in Tucson and Phoenix and the James E. Rogers College of Law, and is affiliated with two academic medical centers (Banner – University Medical Center Tucson and Banner – University Medical Center Phoenix). The University of Arizona is one of three universities governed by the Arizona Board of Regents. The university is part of the Association of American Universities and is the only member from Arizona, and also part of the Universities Research Association . The university is classified among “R1: Doctoral Universities – Very High Research Activity”.

    Known as the Arizona Wildcats (often shortened to “Cats”), The University of Arizona’s intercollegiate athletic teams are members of the Pac-12 Conference of the NCAA. The University of Arizona athletes have won national titles in several sports, most notably men’s basketball, baseball, and softball. The official colors of the university and its athletic teams are cardinal red and navy blue.

    After the passage of the Morrill Land-Grant Act of 1862, the push for a university in Arizona grew. The Arizona Territory’s “Thieving Thirteenth” Legislature approved The University of Arizona in 1885 and selected the city of Tucson to receive the appropriation to build the university. Tucson hoped to receive the appropriation for the territory’s mental hospital, which carried a $100,000 allocation instead of the $25,000 allotted to the territory’s only university Arizona State University was also chartered in 1885, but it was created as Arizona’s normal school, and not a university). Flooding on the Salt River delayed Tucson’s legislators, and by the time they reached Prescott, back-room deals allocating the most desirable territorial institutions had been made. Tucson was largely disappointed with receiving what was viewed as an inferior prize.

    With no parties willing to provide land for the new institution, the citizens of Tucson prepared to return the money to the Territorial Legislature until two gamblers and a saloon keeper decided to donate the land to build the school. Construction of Old Main, the first building on campus, began on October 27, 1887, and classes met for the first time in 1891 with 32 students in Old Main, which is still in use today. Because there were no high schools in Arizona Territory, the university maintained separate preparatory classes for the first 23 years of operation.

    Research

    The University of Arizona is classified among “R1: Doctoral Universities – Very high research activity”. UArizona is the fourth most awarded public university by National Aeronautics and Space Administration for research. The University of Arizona was awarded over $325 million for its Lunar and Planetary Laboratory (LPL) to lead NASA’s 2007–08 mission to Mars to explore the Martian Arctic, and $800 million for its OSIRIS-REx mission, the first in U.S. history to sample an asteroid.

    National Aeronautics Space Agency OSIRIS-REx Spacecraft.

    The LPL’s work in the Cassini spacecraft orbit around Saturn is larger than any other university globally.

    National Aeronautics and Space Administration/European Space Agency [La Agencia Espacial Europea][Agence spatiale européenne][Europäische Weltraumorganisation](EU)/ASI Italian Space Agency [Agenzia Spaziale Italiana](IT) Cassini Spacecraft.

    The University of Arizona laboratory designed and operated the atmospheric radiation investigations and imaging on the probe. The University of Arizona operates the HiRISE camera, a part of the Mars Reconnaissance Orbiter.

    U Arizona NASA Mars Reconnaisance HiRISE Camera.

    NASA Mars Reconnaissance Orbiter.

    While using the HiRISE camera in 2011, University of Arizona alumnus Lujendra Ojha and his team discovered proof of liquid water on the surface of Mars—a discovery confirmed by NASA in 2015. The University of Arizona receives more NASA grants annually than the next nine top NASA/JPL-Caltech-funded universities combined. As of March 2016, The University of Arizona’s Lunar and Planetary Laboratory is actively involved in ten spacecraft missions: Cassini VIMS; Grail; the HiRISE camera orbiting Mars; the Juno mission orbiting Jupiter; Lunar Reconnaissance Orbiter (LRO); Maven, which will explore Mars’ upper atmosphere and interactions with the sun; Solar Probe Plus, a historic mission into the Sun’s atmosphere for the first time; Rosetta’s VIRTIS; WISE; and OSIRIS-REx, the first U.S. sample-return mission to a near-earth asteroid, which launched on September 8, 2016.

    3
    NASA – GRAIL Flying in Formation (Artist’s Concept). Credit: NASA.
    National Aeronautics Space Agency Juno at Jupiter.

    NASA/Lunar Reconnaissance Orbiter.

    NASA/Mars MAVEN

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker. The Johns Hopkins University Applied Physics Lab.
    National Aeronautics and Space Administration Wise/NEOWISE Telescope.

    The University of Arizona students have been selected as Truman, Rhodes, Goldwater, and Fulbright Scholars. According to The Chronicle of Higher Education, UArizona is among the top 25 producers of Fulbright awards in the U.S.

    The University of Arizona is a member of the Association of Universities for Research in Astronomy , a consortium of institutions pursuing research in astronomy. The association operates observatories and telescopes, notably Kitt Peak National Observatory just outside Tucson.

    National Science Foundation NOIRLab National Optical Astronomy Observatory Kitt Peak National Observatory on Kitt Peak of the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers (55 mi) west-southwest of Tucson, Arizona, Altitude 2,096 m (6,877 ft). annotated.

    Led by Roger Angel, researchers in the Steward Observatory Mirror Lab at The University of Arizona are working in concert to build the world’s most advanced telescope. Known as the Giant Magellan Telescope (CL), it will produce images 10 times sharper than those from the Earth-orbiting Hubble Telescope.

    GMT Giant Magellan Telescope(CL) 21 meters, to be at the Carnegie Institution for Science’s NOIRLab NOAO Las Campanas Observatory(CL), some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high.

    The telescope is set to be completed in 2021. GMT will ultimately cost $1 billion. Researchers from at least nine institutions are working to secure the funding for the project. The telescope will include seven 18-ton mirrors capable of providing clear images of volcanoes and riverbeds on Mars and mountains on the moon at a rate 40 times faster than the world’s current large telescopes. The mirrors of the Giant Magellan Telescope will be built at The University of Arizona and transported to a permanent mountaintop site in the Chilean Andes where the telescope will be constructed.

    Reaching Mars in March 2006, the Mars Reconnaissance Orbiter contained the HiRISE camera, with Principal Investigator Alfred McEwen as the lead on the project. This National Aeronautics and Space Agency mission to Mars carrying the UArizona-designed camera is capturing the highest-resolution images of the planet ever seen. The journey of the orbiter was 300 million miles. In August 2007, The University of Arizona, under the charge of Scientist Peter Smith, led the Phoenix Mars Mission, the first mission completely controlled by a university. Reaching the planet’s surface in May 2008, the mission’s purpose was to improve knowledge of the Martian Arctic. The Arizona Radio Observatory , a part of The University of Arizona Department of Astronomy Steward Observatory , operates the Submillimeter Telescope on Mount Graham.

    University of Arizona Radio Observatory at NOAO Kitt Peak National Observatory, AZ USA, U Arizona Department of Astronomy and Steward Observatory at altitude 2,096 m (6,877 ft).

    Kitt Peak National Observatory in the Arizona-Sonoran Desert 88 kilometers 55 mi west-southwest of Tucson, Arizona in the Quinlan Mountains of the Tohono O’odham Nation, altitude 2,096 m (6,877 ft)

    The National Science Foundation funded the iPlant Collaborative in 2008 with a $50 million grant. In 2013, iPlant Collaborative received a $50 million renewal grant. Rebranded in late 2015 as “CyVerse”, the collaborative cloud-based data management platform is moving beyond life sciences to provide cloud-computing access across all scientific disciplines.

    In June 2011, the university announced it would assume full ownership of the Biosphere 2 scientific research facility in Oracle, Arizona, north of Tucson, effective July 1. Biosphere 2 was constructed by private developers (funded mainly by Texas businessman and philanthropist Ed Bass) with its first closed system experiment commencing in 1991. The university had been the official management partner of the facility for research purposes since 2007.

    U Arizona mirror lab-Where else in the world can you find an astronomical observatory mirror lab under a football stadium?

    University of Arizona’s Biosphere 2, located in the Sonoran desert. An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why The University of Arizona is a university unlike any other.

    University of Arizona Landscape Evolution Observatory at Biosphere 2.

     
  • richardmitnick 4:06 pm on June 15, 2022 Permalink | Reply
    Tags: "Discovery Alert:: Two New Rocky Planets in the Solar Neighborhood", Ground based Optical Astronomy, NASA’s TESS mission, Rocky Planets in the Solar Neighborhood", , The new planets: HD 260655 b and HD 260655 c, The TRAPPIST-1 star and planet system with the ESO Belgian robotic Trappist National Telescope at Cerro La Silla in Chile.   

    From NASA : “Discovery Alert:: Two New Rocky Planets in the Solar Neighborhood” 


    From NASA

    June 15, 2022

    Pat Brennan, NASA’s Exoplanet Exploration Program

    1
    Illustration of two newly discovered, rocky “super-Earths” that could be ideal for follow-up atmospheric observations. Credit: NASA/JPL-Caltech.

    The discovery: NASA’s TESS mission has found two rocky worlds orbiting the relatively bright, red dwarf star HD 260655, only 33 light-years away. The new planets, HD 260655 b and HD 260655 c, are among the closest-known rocky planets yet found outside our solar system that astronomers can observe crossing the faces of their stars.

    To confirm the existence of the two new planets, in addition to the observations made by TESS, the scientific team has also used ground-based instrumentation*, such as the CARMENES spectrographs at Calar Alto Observatory (Almeria, Spain) and HIRES at the W. M. Keck Observatory (Mauna Kea, Hawaii).


    These instruments measured the “wobble” of the star, caused by the gravitational tugs from orbiting planets (radial velocity), which yields the planets’ mass. Combining these measurements, it has also been possible to determine the density and confirm that they are rocky worlds.

    *So IAC (ES)

    __________________________________________________________________________________
    National Aeronautics Space Agency/Massachusetts Institute of Technology TESS

    NASA/MIT Tess in the building.

    National Aeronautics Space Agency/Massachusetts Institute of Technology TESS – Transiting Exoplanet Survey Satellite replaced the Kepler Space Telescope in search for exoplanets. TESS is a NASA Astrophysics Explorer mission led and operated by Massachusetts Institute of Technology, and managed by NASA’s Goddard Space Flight Center.


    The Massachusetts Institute of Technology


    The NASA Goddard Space Flight Center

    Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Center for Astrophysics – Harvard and Smithsonian; MIT Lincoln Laboratory; and the NASA Space Telescope Science Institute in Baltimore.


    __________________________________________________________________________________

    Key facts: Using NASA’s orbiting planet hunter, the Transiting Exoplanet Survey Satellite (TESS), scientists discovered sibling planets in Earth’s size-range that are prime candidates for atmospheric investigation. And the discovery comes at an ideal moment: The giant James Webb Space Telescope, soon to deliver its first science images, can examine the atmospheres of exoplanets – planets beyond our solar system – to search for water, carbon molecules and other components. Learning more about the atmospheres of rocky planets will help scientists understand the formation and development of worlds like our own.

    Details: Both planets are “super-Earths” – terrestrial worlds like ours, only bigger. Planet b is about 1.2 times as big around as Earth, planet c 1.5 times. In this case, however, neither world is likely to support life. The temperature on planet b, nearest to the star, is estimated at 816 degrees Fahrenheit (435 Celsius), planet c 543 Fahrenheit (284 Celsius), though actual temperature depends on the presence and nature of possible atmospheres.

    Still, the science team that discovered the planets says they are well worth further investigation. At 33 light-years, they are relatively close to us, and their star, though smaller than ours, is among the brightest in its class. These and other factors raise the likelihood that the Webb telescope, and perhaps even the Hubble Space Telescope, could capture data from the star’s light shining through these planets’ atmospheres.

    Such light can be spread into a spectrum, revealing the fingerprints of molecules within the atmosphere itself.

    Both planets rate in the top 10 candidates for atmospheric characterization among all terrestrial exoplanets so far discovered, the team says. That places them in the same category as one of the most famous planetary systems: the seven roughly Earth-sized planets around a star called TRAPPIST-1.
    ______________________________________________________________
    The TRAPPIST-1 star and planet system; the ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile.

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile interior

    ESO Belgian robotic Trappist-South National Telescope at Cerro La Silla, Chile


    ______________________________________________________________

    The TRAPPIST-1 worlds and several other rocky exoplanets are already on the list of observation targets for the Webb telescope.

    Fun facts: The jury is out on whether either newly discovered planet possesses an atmosphere, and if so, what it’s made of. But the science team’s analysis already has produced some intriguing clues. TESS finds exoplanets by watching for “transits” – the tiny drop in starlight when a planet passes in front of its star – which can reveal the planet’s diameter.

    But the scientists also used data from ground-based telescopes to confirm the existence of the two new planets. These telescopes measured the “wobble” of the star, caused by the gravitational tugs from orbiting planets, which yields the planets’ mass. Combine these measurements, and you can determine the density of the planets – in this case confirming they are rocky worlds. The measurements also suggest that if the planets do have atmospheres, they are not extended, hydrogen atmospheres.

    The discoverers: An international team of astronomers led by Rafael Luque of the Institute of Astrophysics of Andalusia, Spain, and also of the University of Chicago, used TESS data to make the discovery. The team’s paper has been accepted for publication in the science journal, Astronomy & Astrophysics, with presentation of its results at the American Astronomical Society meeting in Pasadena in June 2022.

    See the full article here .

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    Please help promote STEM in your local schools.

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [NASA/ESA Hubble, NASA Chandra, NASA Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 1:22 pm on June 15, 2022 Permalink | Reply
    Tags: "The Tarantula's cosmic web:: astronomers map violent star formation in nebula outside our galaxy", , , Ground based Optical Astronomy, , the Tarantula Nebula is one of the brightest and most active star-forming regions in our galactic neighbourhood.   

    From The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral] [Europäische Südsternwarte](EU)(CL): “The Tarantula’s cosmic web:: astronomers map violent star formation in nebula outside our galaxy” 

    ESO 50 Large

    From The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral] [Europäische Südsternwarte](EU)(CL)

    15 June 2022

    Tony Wong
    Astronomy Department, University of Illinois
    Urbana-Champaign, IL, USA
    Tel: +1 217 244 4207
    Email: wongt@illinois.edu

    Guido De Marchi
    European Space Research and Technology Centre, European Space Agency
    Noordwijk, Netherlands
    Tel: +31 71 565 8332
    Cell: +31 6 5081 6906
    Email: gdemarchi@esa.int

    Bárbara Ferreira
    ESO Media Manager
    Garching bei München, Germany
    Tel: +49 89 3200 6670
    Cell: +49 151 241 664 00
    Email: press@eso.org

    1
    Astronomers have unveiled intricate details of the star-forming region 30 Doradus-also known as the Tarantula Nebula, using new observations from the Atacama Large Millimeter/submillimeter Array (ALMA)[below]. In a high-resolution image released today by the European Southern Observatory (ESO) and including ALMA data, we see the nebula in a new light, with wispy gas clouds that provide insight into how massive stars shape this region.

    2
    This image shows the star-forming region 30 Doradus, also known as the Tarantula Nebula, in radio wavelengths, as observed by the Atacama Large Millimeter/submillimeter Array (ALMA). The bright red-yellow streaks reveal regions of cold, dense gas which have the potential to collapse and form stars. The unique web-like structure of the gas clouds is characteristic of the Tarantula Nebula. Credit: ALMA (ESO/NAOJ/NRAO)/Wong et al.

    3
    This infrared image shows the star-forming region 30 Doradus, also known as the Tarantula Nebula, highlighting its bright stars and light, pinkish clouds of hot gas. The image is a composite: it was captured by the HAWK-I instrument on ESO’s Very Large Telescope (VLT) [below] and the Visible and Infrared Survey Telescope for Astronomy (VISTA) [below]. Credit: ESO, M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit.


    This video starts with a view of the star-forming region 30 Doradus, also known as the Tarantula Nebula, in optical wavelengths, taken with ESO’s 2.2-metre telescope at La Silla Observatory. Located in the southern constellation of Dorado (The Dolphinfish) in the nearby Large Magellanic Cloud, the Tarantula Nebula is known for its unique, web-like clouds.

    During the video, the image shifts to an infrared view of the Tarantula Nebula. The infrared data are provided by ESO’s Very Large Telescope (VLT) and the Visible and Infrared Survey Telescope for Astronomy (VISTA) and reveal pinkish clouds of hot gas. Radio data taken by the Atacama Large Millimeter/submillimeter Array (ALMA) are then overlaid, represented by bright red-yellow streaks. These streaks highlight the locations of cold, dense gas clouds that have the potential to collapse and form new stars. The radio data are then presented on their own, displaying in detail some of the spidery structures that originally gave rise to the moniker Tarantula Nebula. Credit: ESO/M. Kornmesser, ALMA (ESO/NAOJ/NRAO)/Wong et al., ESO/M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit.


    This zoom video starts with a wide view of the Milky Way and ends with a close-up look at a rich region of star formation in the nearby Large Magellanic Cloud, in the southern constellation of Dorado (The Dolphinfish). The specific region shown, 30 Doradus, is also known as the Tarantula Nebula.

    The final view of these clouds was captured by ESO’s Very Large Telescope and the Visible and Infrared Survey Telescope for Astronomy (VISTA) [below], and overlaid with new radio data taken by the Atacama Large Millimeter/submillimeter Array (ALMA). The ALMA data reveal bright yellow-red streaks of cold, dense gas that have the potential to collapse and form new stars.
    Credit: ESO/Digitized Sky Survey 2/N. Risinger (skysurvey.org)/R. Gendler (http://www.robgendlerastropics.com/), ALMA (ESO/NAOJ/NRAO)/Wong et al., ESO/M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit. Music: John Dyson.

    “These fragments may be the remains of once-larger clouds that have been shredded by the enormous energy being released by young and massive stars, a process dubbed feedback,” says Tony Wong, who led the research on 30 Doradus presented today at the American Astronomical Society (AAS) meeting and published in The Astrophysical Journal. Astronomers originally thought the gas in these areas would be too sparse and too overwhelmed by this turbulent feedback for gravity to pull it together to form new stars. But the new data also reveal much denser filaments where gravity’s role is still significant. “Our results imply that even in the presence of very strong feedback, gravity can exert a strong influence and lead to a continuation of star formation,” adds Wong, who is a professor at the University of Illinois at Urbana-Champaign, USA.

    Located in the Large Magellanic Cloud, a satellite galaxy of our own Milky Way, the Tarantula Nebula is one of the brightest and most active star-forming regions in our galactic neighbourhood, lying about 170 000 light-years away from Earth.

    At its heart are some of the most massive stars known, a few with more than 150 times the mass of our Sun, making the region perfect for studying how gas clouds collapse under gravity to form new stars.

    “What makes 30 Doradus unique is that it is close enough for us to study in detail how stars are forming, and yet its properties are similar to those found in very distant galaxies, when the Universe was young,” said Guido De Marchi, a scientist at the European Space Agency (ESA) and a co-author of the paper presenting the new research. “Thanks to 30 Doradus, we can study how stars used to form 10 billion years ago when most stars were born.”

    While most of the previous studies of the Tarantula Nebula have focused on its centre, astronomers have long known that massive star formation is happening elsewhere too. To better understand this process, the team conducted high-resolution observations covering a large region of the nebula. Using ALMA [below], they measured the emission of light from carbon monoxide gas. This allowed them to map the large, cold gas clouds in the nebula that collapse to give birth to new stars — and how they change as huge amounts of energy are released by those young stars.

    “We were expecting to find that parts of the cloud closest to the young massive stars would show the clearest signs of gravity being overwhelmed by feedback,” says Wong. “We found instead that gravity is still important in these feedback-exposed regions — at least for parts of the cloud that are sufficiently dense.”

    In the image released today by ESO, we see the new ALMA data overlaid on a previous infrared image of the same region that shows bright stars and light pinkish clouds of hot gas, taken with ESO’s Very Large Telescope (VLT)[below] and ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA)[below]. The composition shows the distinct, web-like shape of the Tarantula Nebula’s gas clouds that gave rise to its spidery name. The new ALMA data comprise the bright red-yellow streaks in the image: very cold and dense gas that could one day collapse and form stars.

    The new research contains detailed clues about how gravity behaves in the Tarantula Nebula’s star-forming regions, but the work is far from finished. “There is still much more to do with this fantastic data set, and we are releasing it publicly to encourage other researchers to conduct new investigations,” Wong concludes.

    More information

    This research is being presented at the 240th meeting of the American Astronomical Society (AAS) in the press conference titled Stars, Their Environments & Their Planets (Wednesday, 15 June, 19:15 CEST / 10:15 PT). Reporters are welcome to watch the live stream of the press conference, which will be visible publicly on the AAS Press Office YouTube channel: https://www.youtube.com/c/AASPressOffice.

    The research is also presented in the paper The 30 Doradus Molecular Cloud at 0.4 Parsec Resolution with ALMA: Physical Properties and the Boundedness of CO Emitting Structures to appear in The Astrophysical Journal.

    The team is composed of T. Wong (Astronomy Department, University of Illinois, USA [Illinois]), L. Oudshoorn (Leiden Observatory, Leiden University, The Netherlands [Leiden]), E. Sofovich (Illinois), A. Green (Illinois), C. Shah (Illinois), R. Indebetouw (Department of Astronomy, University of Virginia, USA and National Radio Astronomy Observatory, USA [NRAO]), M. Meixner (SOFIA-USRA, NASA Ames Research Center, USA), A. Hacar (Department of Astrophysics, University of Vienna, Austria), O. Nayak (Space Telescope Science Institute, USA [STSci]), K. Tokuda (Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, Japan and National Astronomical Observatory of Japan, National Institutes of Natural Sciences, Japan and Department of Physics, Graduate School of Science, Osaka Metropolitan University, Japan [Osaka]), A. D. Bolatto (Department of Astronomy and Joint Space Science Institute, University of Maryland, USA and NRAO Visiting Astronomer), M. Chevance (Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Germany), G. De Marchi (European Space Research and Technology Centre, Netherlands), Y. Fukui (Department of Physics, Nagoya University, Japan), A. S. Hirschauer (STSci), K. E. Jameson (CSIRO, Space and Astronomy, Australia), V. Kalari (International Gemini Observatory, NSF’s NOIRLab, Chile), V. Lebouteiller (AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, France), L. W. Looney (Illinois), S. C. Madden (Departement d’Astrophysique AIM/CEA Saclay, France), Toshikazu Onishi (Osaka), J. Roman-Duval (STSci), M. Rubio (Departamento de Astronomía, Universidad de Chile, Chile) and A. G. G. M. Tielens (Department of Astronomy, University of Maryland, USA and Leiden).

    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    Helium is the second-most-abundant element in the universe, but on Earth it’s relatively rare. It results from the decay of uranium, can’t be artificially created, and is produced as a byproduct of natural gas refinement. Only a limited number of countries produce it, with the U.S. and Russia among top suppliers. Because that’s the case, it only takes a handful of supply disruptions to trigger a crisis — the gas industry refers to the current one as “Helium shortage 4.0,” it being the fourth since 2006.

    See the full article here .


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    The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral][Europäische Südsternwarte] (EU)(CL) is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. today ESO is supported by 16 Member States (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO carries out an ambitious program focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organizing cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: Cerro La Silla, Cerro Paranaland Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration in astronomy. Established as an intergovernmental organisation in 1962, ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. At Paranal ESO will host and operate the Čerenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory.


    Cerro La Silla HELIOS (HARPS Experiment for Light Integrated Over the Sun).

    3.6m telescope & HARPS at Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    MPG Institute for Astronomy [MPG-Institut für Astronomie](DE) European Southern Observatory(EU) 2.2 meter telescope at Cerro La Silla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    European Southern Observatory (EU) Cerro La Silla Observatory 600 km north of Santiago de Chile at an altitude of 2400 metres.

    European Southern Observatory(EU) , Very Large Telescope at Cerro Paranal in the Atacama Desert •ANTU (UT1; The Sun ) •KUEYEN (UT2; The Moon ) •MELIPAL (UT3; The Southern Cross ), and •YEPUN (UT4; Venus – as evening star). Elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo.

    European Southern Observatory(EU) VLTI Interferometer image, Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level, •ANTU (UT1; The Sun ), •KUEYEN (UT2; The Moon ), •MELIPAL (UT3; The Southern Cross ), and •YEPUN (UT4; Venus – as evening star).

    ESO VLT Survey telescope.

    ESO Very Large Telescope 4 lasers on Yepun (CL).

    Glistening against the awesome backdrop of the night sky above ESO’s Paranal Observatory, four laser beams project out into the darkness from Unit Telescope 4 UT4 of the VLT, a major asset of the Adaptive Optics system.

    ESO New Technology Telescope at Cerro La Silla, at an altitude of 2400 metres.

    Part of ESO’s Paranal Observatory the VLT Survey Telescope (VISTA) observes the brilliantly clear skies above the Atacama Desert of Chile. It is the largest survey telescope in the world in visible light, with an elevation of 2,635 metres (8,645 ft) above sea level.

    European Southern ObservatoryNational Radio Astronomy Observatory(US)National Astronomical Observatory of Japan(JP) ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres.

    European Southern Observatory(EU) ELT 39 meter telescope to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    European Southern Observatory(EU)/MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE) ESO’s Atacama Pathfinder Experiment(CL) high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft).

    The Leiden Observatory [Sterrewacht Leiden](NL) MASCARA instrument cabinet at Cerro La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft).

    ESO Next Generation Transit Survey telescopes, an array of twelve robotic 20-centimetre telescopes at Cerro Paranal, 2,635 metres (8,645 ft) above sea level.


    ESO Speculoos telescopes four 1 meter robotic telescopes at ESO Paranal Observatory 2635 metres 8645 ft above sea level.

    TAROT telescope at Cerro LaSilla, 2,635 metres (8,645 ft) above sea level.

    European Southern Observatory (EU) ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres.

    A novel gamma ray telescope under construction on Mount Hopkins, Arizona. A large project known as the Čerenkov Telescope Array composed of hundreds of similar telescopes to be situated in the Canary Islands and Chile at, ESO Cerro Paranal site The telescope on Mount Hopkins will be fitted with a prototype high-speed camera, assembled at the University of Wisconsin–Madison and capable of taking pictures at a billion frames per second. Credit: Vladimir Vassiliev.

    European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU), The new Test-Bed Telescope 2 is housed inside the shiny white dome shown in this picture, at ESO’s Cerro LaSilla Facility in Chile. The telescope has now started operations and will assist its northern-hemisphere twin in protecting us from potentially hazardous, near-Earth objects. The domes of ESO’s 0.5 m and the Danish 0.5 m telescopes are visible in the background of this image.Part of the world-wide effort to scan and identify near-Earth objects, the European Space Agency’s Test-Bed Telescope 2 (TBT2), a technology demonstrator hosted at ESO’s La Silla Observatory, has now started operating. Working alongside its northern-hemisphere partner telescope, TBT2 will keep a close eye on the sky for asteroids that could pose a risk to Earth, testing hardware and software for a future telescope network.

    European Space Agency [La Agencia Espacial Europea][Agence spatiale européenne][Europäische Weltraumorganisation](EU) ‘s The open dome of The black telescope structure of the European Space Agency Test-Bed Telescope 2 peers out of its open dome in front of the rolling desert landscape. The telescope is located at ESO’s Cerro La Silla Observatory, which sits at a 2400 metre altitude in the Chilean Atacama Desert.

     
  • richardmitnick 8:41 pm on June 8, 2022 Permalink | Reply
    Tags: "Strange Radio Burst Raises New Questions", , , , FRB 121102 found in 2016, FRB 190520 found in 2019, Ground based Optical Astronomy, ,   

    From The National Radio Astronomy Observatory: “Strange Radio Burst Raises New Questions” 

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    From The National Radio Astronomy Observatory

    June 8, 2022
    Dave Finley
    Public Information Officer
    (505) 241-9210
    dfinley@nrao.edu

    Astronomers have found only the second example of a highly active, repeating Fast Radio Burst (FRB) with a compact source of weaker but persistent radio emission between bursts. The discovery raises new questions about the nature of these mysterious objects and also about their usefulness as tools for studying the nature of intergalactic space. The scientists used the National Science Foundation’s Karl G. Jansky Very Large Array (VLA)[below] and other telescopes to study the object, first discovered in 2019.

    1
    Artist’s conception of a neutron star with an ultra-strong magnetic field, called a magnetar, emitting radio waves (red). Magnetars are a leading candidate for what generates Fast Radio Bursts.
    Credit: Bill Saxton, NRAO/AUI/NSFCredit: B. Saxton NRAO/AUI/NSF

    2
    VLA image of Fast Radio Burst FRB 190520 (red), combined with optical image, when the FRB is bursting.
    Artist’s conception of a neutron star with an ultra-strong magnetic field, called a magnetar, emitting radio waves (red). Magnetars are a leading candidate for what generates Fast Radio Bursts. Credit: Niu, et al.; Bill Saxton, NRAO/AUI/NSF; CFHT


    The object, called FRB 190520, was found by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China.

    A burst from the object occurred on May 20, 2019, and was found in data from that telescope in November of that year. Follow-up observations with FAST showed that, unlike many other FRBs, it emits frequent, repeating bursts of radio waves.

    Observations with the VLA in 2020 pinpointed the object’s location, and that allowed visible-light observations with the Subaru telescope in Hawaii to show that it is in the outskirts of a dwarf galaxy nearly 3 billion light-years from Earth.


    The VLA observations also found that the object constantly emits weaker radio waves between bursts.

    “These characteristics make this one look a lot like the very first FRB whose position was determined — also by the VLA — back in 2016,” said Casey Law, of Caltech. That development was a major breakthrough, providing the first information about the environment and distance of an FRB. However, its combination of repeating bursts and persistent radio emission between bursts, coming from a compact region, set the 2016 object, called FRB 121102, apart from all other known FRBs, until now.

    4
    The region of FRB 190520, seen in visible light, with VLA image of the Fast Radio Burst alternating between the object bursting and not bursting. Credit: Niu, et al.; Bill Saxton, NRAO/AUI/NSF; CFHT

    “Now we have two like this, and that brings up some important questions,” Law said. Law is part of an international team of astronomers reporting their findings in the journal Nature.

    The differences between FRB 190520 and FRB 121102 and all the others strengthen a possibility suggested earlier that there may be two different kinds of FRBs.

    “Are those that repeat different from those that don’t? What about the persistent radio emission — is that common?” said Kshitij Aggarwal, a graduate student at West Virginia University (WVU).

    The astronomers suggest that there may be either two different mechanisms producing FRBs or that the objects producing them may act differently at different stages of their evolution. Leading candidates for the sources of FRBs are the superdense neutron stars left over after a massive star explodes as a supernova, or neutron stars with ultra-strong magnetic fields, called magnetars.

    One characteristic of FRB 190520 calls into question the usefulness of FRBs as tools for studying the material between them and Earth. Astronomers often analyze the effects of intervening material on the radio waves emitted by distant objects to learn about that tenuous material itself. One such effect occurs when radio waves pass through space that contains free electrons. In that case, higher-frequency waves travel more quickly than lower-frequency waves.

    This effect, called dispersion, can be measured to determine the density of electrons in the space between the object and Earth, or, if the electron density is known or assumed, provide a rough estimate of the distance to the object. The effect often is used to make distance estimates to pulsars.

    That didn’t work for FRB 190520. An independent measurement of the distance based on the Doppler shift of the galaxy’s light caused by the expansion of the Universe placed the galaxy at nearly 3 billion light-years from Earth. However, the burst’s signal shows an amount of dispersion that ordinarily would indicate a distance of roughly 8 to 9.5 billion light-years.

    “This means that there is a lot of material near the FRB that would confuse any attempt to use it to measure the gas between galaxies,” Aggarwal said. “If that’s the case with others, then we can’t count on using FRBs as cosmic yardsticks,” he added.

    The astronomers speculated that FRB 190520 may be a “newborn,” still surrounded by dense material ejected by the supernova explosion that left behind the neutron star. As that material eventually dissipates, the dispersion of the burst signals also would decline. Under the “newborn” scenario, they said, the repeating bursts also might be a characteristic of younger FRBs and dwindle with age.

    “The FRB field is moving very fast right now and new discoveries are coming out monthly. However, big questions still remain, and this object is giving us challenging clues about those questions,” said Sarah Burke-Spolaor, of WVU.

    See the full article here .


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    The National Radio Astronomy Observatory is a facility of The National Science Foundation, operated under cooperative agreement by The Associated Universities, Inc.


    National Radio Astronomy Observatory Karl G Jansky Very Large Array located in central New Mexico on the Plains of San Agustin, between the towns of Magdalena and Datil, ~50 miles (80 km) west of Socorro. The VLA comprises twenty-eight 25-meter radio telescopes.

    ngVLA, to be located near the location of the NRAO Karl G. Jansky Very Large Array site on the plains of San Agustin, fifty miles west of Socorro, NM, at an elevation of 6970 ft (2124 m) with additional mid-baseline stations currently spread over greater New Mexico, Arizona, Texas, and Mexico.

    National Radio Astronomy Observatory Very Long Baseline Array.

    The European Southern Observatory [La Observatorio Europeo Austral][Observatoire européen austral][Europäische Südsternwarte](EU)(CL))/National Radio Astronomy Observatory/National Astronomical Observatory of Japan(JP) ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres.

    Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).

    *The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

    Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.

     
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