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  • richardmitnick 1:53 pm on April 10, 2020 Permalink | Reply
    Tags: "VLASS A Survey of the Radio Sky", , Astrophysics, , , ,   

    From Harvard-Smithsonian Center for Astrophysics: “VLASS, A Survey of the Radio Sky” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    Technological advances in recent years have increased the sensitivity of radio interferometers like the Karl G. Jansky Very Large Array (VLA) to the radio emission from astronomical sources in their continuum (not only in their lines) by factors of several, enabling them to see fainter and more distant objects.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    Radio interferometers obtain high spatial resolution details of astronomical sources, and the new VLA, in addition to its sensitivity and high resolution, can provide information about the polarization of the emission, enable more reliable large-scale mosaic images, and with repeating observations monitor temporal variations. Not least, a series of recent sensitive sky surveys at optical and infrared wavelengths justify completing a corresponding radio survey. When combined, these multi-wavelength all-sky surveys will permit astronomers to characterize stellar and galaxy populations in unprecedented detail.

    1
    The radio source 3C402. The greyscale background is an optical image of the field while the contours show earlier radio imaging results. The insets are new radio images from VLASS that show the previous radio source is actually two separate galaxies. VLASS; Lacy et al. 2020

    CfA astronomers Edo Berger, Atish Kamble, and Peter Williams are members of the VLASS (The Very Large Array Sky Survey) team, a large group working on a unique radio all-sky survey having all the aforementioned capabilities and able to cover all of the sky visible from the VLA location in New Mexico. VLASS science has four themes: finding otherwise hidden explosions and/or transient events, probing astrophysical magnetic fields, imaging galaxies both near and distant, and using radio wavelengths to peer through dust obscuration effects to study the Milky Way. Each theme contains numerous subtopics. Hidden explosions, for example, will probe the explosive death throes of massive stars including supernovae, their role in cosmological studies, gamma-ray bursts; signs of mergers between black holes and neutron stars will have implications for gravitational wave detections.

    VLASS observations, begun in September 2017, are expected to be completed in 2024. In a new paper [PASP], the team reviews the VLASS goals and first-look results from early observations, showing how the data successfully demonstrate the ability of the project to achieve all its proposed goals. VLASS includes an integral education and outreach component with two workshops on data visualization held in the first year to train users to produce images that are aesthetic as well as scientifically accurate. The first preliminary data and materials are now available to scientists and the public.

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 1:39 pm on April 10, 2020 Permalink | Reply
    Tags: "Center for Astrophysics Scientist and Team First to Measure Wind Speed on an Object Outside the Solar System", 2MASS J1047+21, , Astrophysics, , ,   

    From Harvard-Smithsonian Center for Astrophysics: “Center for Astrophysics Scientist and Team First to Measure Wind Speed on an Object Outside the Solar System” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    April 9, 2020

    Amy Oliver
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    Fred Lawrence Whipple Observatory
    520-879-4402
    amy.oliver@cfa.harvard.edu

    1
    Artist’s conception of the atmospheric rotation of brown dwarf 2MASS J1047+21, which was measured at 1.741 hours. Credit: NRAO

    An international collaboration of scientists—with key contributions from the Center for Astrophysics | Harvard & Smithsonian—today announced the first measurement of atmospheric wind speed ever recorded outside the solar system using a novel technique.

    Researchers focused their efforts on 2MASS J1047+21, a cool brown dwarf located 33.2 light years from Earth, and clocked wind speeds at 650 meters per second, or 1,450 miles per hour. “For the first time ever, we measured the speed of the winds of a brown dwarf—too big to be a planet, too small to be a star,” said Peter K.G. Williams, Innovation Scientist for CfA and the American Astronomical Society. Williams led the radio astronomical observations that made the result possible. “The results rule out a few unusual models and prove that this new technique works and can be applied to more objects.”

    Prior to the study, scientists had only scientifically measured wind speeds within the solar system, leaving scientists to guess at the atmospheric natures of bodies beyond the solar system. “While we have long been able to directly probe the atmospheres and winds of the bodies in our own solar system, we’ve had to conjecture what they’re like in other kinds of bodies, and if there’s one thing we’ve learned from our studies of extrasolar bodies thus far, it’s that our primary conjectures often turn out to be wrong,” said Williams. “This new technique opens the way to better understanding the behavior of atmospheres that are unlike anything found in our solar system.”

    Using a combination of radio and infrared emissions, the new technique can be more broadly applied to those objects too far away for scientists to observe cloud movement in the atmosphere, like brown dwarfs and exoplanets. “Even though brown dwarfs are completely covered in clouds, they’re too far away for us to pick out individual clouds like we do on planets within our solar system, but we can still measure how long it takes for a group of clouds to do a lap around the atmosphere; as clouds come in and out of view they change the brightness of the planet,” said Williams. “This lap time depends on two things: how fast the brown dwarf itself is spinning, and how fast the wind is blowing on top of that.”

    Cloud movement alone, however, couldn’t produce an accurate measurement of atmospheric wind speeds on the brown dwarf, and researchers also looked to radio wave emissions for a measurement of the brown dwarf’s rotation beneath its atmosphere. “It turns out that in some brown dwarfs it’s possible to measure this spin rate by detecting radio waves,” said Williams. “We observed a pulse of radio waves every time the brown dwarf rotated. This is because the radio waves come from high-energy particles trapped in its magnetic field, and its magnetic field is rooted deep in its interior—just like Earth—where there’s no wind to alter the measurement. By taking the difference between the cloud lap time and the radio pulse time, we were able to determine the wind speed.”

    This work was accomplished by combining radio observations from the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) observatory and infrared observations from NASA’s Spitzer Space Telescope.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    NASA/Spitzer Infrared Telescope. No longer in service.

    The study rules out some current theoretical models of how brown dwarf atmospheres work, and Williams believes the results, published in Science, will both better constrain theoretical models for the future and guide the efforts of theorists working in exoplanetary atmospheric studies.

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 9:59 am on April 9, 2020 Permalink | Reply
    Tags: "Black Hole Bends Light Back on Itself", A black hole that is orbited by a sun-like star; together the pair is called XTE J1550-564., , Astrophysics, , , ,   

    From Caltech : “Black Hole Bends Light Back on Itself” 

    Caltech Logo

    From Caltech

    April 08, 2020

    Whitney Clavin
    (626) 395‑1944
    wclavin@caltech.edu

    New study proves a theory first predicted more than 40 years ago.

    1
    This illustration shows how some of the light coming from a disk around a black hole is bent back onto the disk itself due to the gravity of the hefty black hole. The light is then reflected back off the disk. Astronomers using data from NASA’s now-defunct Rossi X-ray Timing Explorer (RXTE) mission were able to distinguish between light that came straight from the disk and light that was reflected. The bluish material coming off the black hole is an outflowing jet of energetic particles. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)/R. Connors (Caltech)

    You may have heard that nothing escapes the gravitational grasp of a black hole, not even light. This is true in the immediate vicinity of a black hole, but a bit farther out—in disks of material that swirl around some black holes—light can escape. In fact, this is the reason actively growing black holes shine with brilliant X-rays.

    Now, a new study accepted for publication in The Astrophysical Journal offers evidence that, in fact, not all of the light streaming from a black hole’s surrounding disk easily escapes. Some of it gives in to the monstrous pull of the black hole, turns back, and then ultimately bounces off the disk and escapes.

    “We observed light coming from very close to the black hole that is trying to escape, but instead is pulled right back by the black hole like a boomerang,” says Riley Connors, lead author of the new study and a postdoctoral scholar at Caltech. “This is something that was predicted in the 1970s, but hadn’t been shown until now.”

    The new findings were made possible by combing through archival observations from NASA’s now-defunct Rossi X-ray Timing Explorer (RXTE) mission, which came to an end in 2012.

    NASA/ROSSI

    The researchers specifically looked at a black hole that is orbited by a sun-like star; together, the pair is called XTE J1550-564. The black hole “feeds” off this star, pulling material onto a flat structure around it called an accretion disk. By looking closely at the X-ray light coming from the disk as the light spirals toward the black hole, the team found imprints indicating that the light had been bent back toward the disk and reflected off.

    “The disk is essentially illuminating itself,” says co-author Javier Garcia, a research assistant professor of physics at Caltech. “Theorists had predicted what fraction of the light would bend back on the disk, and now, for the first time, we have confirmed those predictions.”

    The scientists say that the new results offer another indirect confirmation of Albert Einstein’s general theory of relativity, and also will help in future measurements of the spin rates of black holes, something that is still poorly understood.

    “Since black holes can potentially spin very fast, they not only bend the light but twist it,” says Connors. “These recent observations are another piece in the puzzle of trying to figure out how fast black holes spin.”

    The new study, titled, “Evidence for Returning Disk Radiation in the Black Hole X-ray Binary XTEJ1550-564,” was funded by NASA, the Alexander von Humboldt Foundation, and the Margarete von Wrangell Fellowship. Other co-authors are Thomas Dauser, Stefan Licklederer, and Jörn Wilms of The University of Erlangen-Nüremberg in Germany; Victoria Grinberg of the Universität Tübingen in Germany; James Steiner of the MIT Kavli Institute for Astrophysics and Space Research and Harvard University; Navin Sridhar of Columbia University; John Tomsick of UC Berkeley; and Fiona Harrison, the Harold A. Rosen Professor of Physics at Caltech and the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy.

    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 California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 11:59 am on April 7, 2020 Permalink | Reply
    Tags: "Clemson researchers capture first-ever photographic proof of power-packed jet emerging from colliding galaxies", , Astrophysics, , ,   

    From Clemson University: “Clemson researchers capture first-ever photographic proof of power-packed jet emerging from colliding galaxies” 

    From Clemson University

    April 7, 2020
    Laura Schmitt

    A team of Clemson University College of Science researchers, in collaboration with international colleagues, has reported the first definitive detection of a relativistic jet emerging from two colliding galaxies — in essence, the first photographic proof that merging galaxies can produce jets of charged particles that travel at nearly the speed of light.

    Furthermore, scientists had previously discovered that these jets could be found in elliptical-shaped galaxies, which can be formed in the merging of two spiral galaxies. Now, they have an image showing the formation of a jet from two younger, spiral-shaped galaxies.

    1
    The Seyfert 1 galaxy, TXS 2116-077, (seen on the right) collides with another spiral-shaped galaxy of similar mass, creating a relativistic jet in the TXS’s center. Both galaxies have active galactic nuclei (AGN). Image Credit: Courtesy Vaidehi Paliya

    “For the first time, we have found two spiral- or disk-shaped galaxies on path for a collision that have produced a nascent, baby jet that has just started its life at the center of one of the galaxies,” said Vaidehi Paliya, a former Clemson post-doctoral researcher and lead author of the findings reported in The Astrophysical Journal on April 7, 2020.

    The paper is titled “TXS 2116-077: A gamma-ray emitting relativistic jet hosted in a galaxy merger.” In addition to Paliya, who is now at the Deutsches Elektronen Synchrotron (DESY) in Germany, the other Clemson authors include associate professor Marco Ajello, professor Dieter Hartmann, and adjunct professor Stefano Marchesi of the department of physics and astronomy.

    The fact that the jet is so young enabled the researchers to clearly see its host.

    According to Ajello, others have already imaged galactic collisions many times. But he and his colleagues are the first to capture two galaxies merging where there is a fully formed jet pointing at us — albeit, a very young one, and thus not yet bright enough to blind us.

    “Typically, a jet emits light that is so powerful we can’t see the galaxy behind it,” Marchesi said. “It’s like trying to look at an object and someone points a bright flashlight into your eyes. All you can see is the flashlight. This jet is less powerful, so we can actually see the galaxy where it is born.”

    Jets are the most powerful astrophysical phenomena in the universe. They can emit more energy into the universe in one second than our sun will produce in its entire lifetime. That energy is in the form of radiation, such as intense radio waves, X-rays, and gamma-rays.

    “Jets are the best accelerators in the universe — far better than the super colliders we have on Earth,” said Hartmann, referring to accelerators used in high-energy physics studies.

    Jets were thought to be born from older, elliptical-shaped galaxies with an active galactic nucleus (AGN), which is a super-massive black hole that resides at its center. As a point of reference, scientists believe all galaxies have centrally located super-massive black holes, but not all of them are AGNs. For example, our Milky Way’s massive black hole is dormant.

    Scientists theorize that the AGNs grow larger by gravitationally drawing in gas and dust through a process called accretion. But not all of this matter gets accreted into the black hole. Some of the particles become accelerated and are spewed outward in narrow beams in the form of jets.

    “It’s hard to dislodge gas from the galaxy and have it reach its center,” Ajello explained. “You need something to shake the galaxy a little bit to make the gas get there. The merging or colliding of galaxies is the easiest way to move the gas, and if enough gas moves, then the super-massive black hole will become extremely bright and could potentially develop a jet.”

    Ajello believes that the team’s image captured the two galaxies, a Seyfert 1 galaxy known as TXS 2116-077 and another galaxy of similar mass, as they were colliding for the second time because of the amount of gas seen in the image.

    “Eventually, all the gas will be expelled into space, and without gas, a galaxy cannot form stars anymore,” Ajello said. “Without gas, the black hole will switch off and the galaxy will lay dormant.”

    Billions of years from now, our own Milky Way will merge with the nearby Andromeda galaxy.

    “Scientists have carried out detailed numerical simulations and predicted that this event may ultimately lead to the formation of one giant elliptical galaxy,” said Paliya. “Depending on the physical conditions, it may host a relativistic jet, but that’s in the distant future.”

    The team captured the image using one of the largest land-based telescopes in the world, the Subaru 8.2-meter optical infrared telescope located on a mountain summit in Hawaii. They performed subsequent observations with the Gran Telescopio Canarias and William Herschel Telescope on the island of La Palma off the coast of Spain, as well as with NASA’s Chandra X-Ray Observatory space telescope.

    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, Spain, sited on a volcanic peak 2,267 metres (7,438 ft) above sea level

    ING 4.2 meter William Herschel Telescope at Roque de los Muchachos Observatory on La Palma in the Canary Islands, 2,396 m (7,861 ft)

    NASA/Chandra X-ray Telescope

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Ranked as the 27th best national public university by U.S. News & World Report, Clemson is dedicated to teaching, research and service. Founded in 1889, we remain committed both to world-class research and a high quality of life. In fact, 92 percent of our seniors say they’d pick Clemson again if they had it to do over.

    Clemson’s retention and graduation rates rank among the highest in the country for public universities. We’ve been named among the “Best Public College Values” by Kiplinger magazine in 2019, and The Princeton Review named us among the “Best Value Colleges” for 2020.

    Our beautiful college campus sits on 20,000 acres in the foothills of the Blue Ridge Mountains, along the shores of Lake Hartwell. And we also have research facilities and economic development hubs throughout the state of South Carolina — in Anderson, Blackville, Charleston, Columbia, Darlington, Georgetown, Greenville, Greenwood, and Pendleton.

    The research, outreach and entrepreneurial projects led by our faculty and students are driving economic development and improving quality of life in South Carolina and beyond. In fact, a recent study determined that Clemson has an annual $1.9 billion economic impact on the state.

    Just as founder Thomas Green Clemson intertwined his life with the state’s economic and educational development, the Clemson Family impacts lives daily with their teaching, research and service.
    How Clemson got its start

    University founders Thomas Green and Anna Calhoun Clemson had a lifelong interest in education, agricultural affairs and science.

    In the post-Civil War days of 1865, Thomas Clemson looked upon a South that lay in economic ruin, once remarking, “This country is in wretched condition, no money and nothing to sell. Everyone is ruined, and those that can are leaving.”

    Thomas Clemson’s death on April 6, 1888, set in motion a series of events that marked the start of a new era in higher education in South Carolina. In his will, he bequeathed the Fort Hill plantation and a considerable sum from his personal assets for the establishment of an educational institution that would teach scientific agriculture and the mechanical arts to South Carolina’s young people.

    Clemson Agricultural College formally opened as an all-male military school in July 1893 with an enrollment of 446. It remained this way until 1955 when the change was made to “civilian” status for students, and Clemson became a coeducational institution. In 1964, the college was renamed Clemson University as the state legislature formally recognized the school’s expanded academic offerings and research pursuits.

    More than a century after its opening, the University provides diverse learning, research facilities and educational opportunities not only for the people of the state — as Thomas Clemson dreamed — but for thousands of young men and women throughout the country and the world.

     
  • richardmitnick 11:21 am on April 7, 2020 Permalink | Reply
    Tags: , , Astrophysics, , , SPT-CL J2106-5844- the most massive distant (farther than roughly 8 billion light-years) galaxy cluster known.   

    From AAS NOVA: ” Featured Image: A Distant Cluster Tips the Scales” 

    AASNOVA

    From AAS NOVA

    6 April 2020
    Susanna Kohler

    1

    You’re looking at SPT-CL J2106-5844, the most massive distant (farther than roughly 8 billion light-years) galaxy cluster known. This composite image (click for the full view) shows the field of the cluster, which spans a distance of roughly 3 million light-years across, in three Hubble color filters. The overlaid contours show the distribution of mass within the cluster, as recently determined by a team of scientists led by Jinhyub Kim (Yonsei University, Republic of Korea; University of California, Davis). Kim and collaborators used weak gravitational lensing — slight distortions in the shapes of background galaxies caused when their light is bent by the massive gravitational pull of this cluster — to map out the tremendous mass of SPT-CL J2106-5844.

    Weak gravitational lensing NASA/ESA Hubble

    They find this cluster weighs in at a whopping ~1 quadrillion (1015) solar masses! Studying this distant, monster cluster can help us place constraints on how the universe’s large-scale structure formed and evolved. To read more about what the authors learned, check out the article below.

    Citation

    “Precise Mass Determination of SPT-CL J2106-5844, the Most Massive Cluster at z > 1,” Jinhyub Kim et al 2019 ApJ 887 76.
    https://iopscience.iop.org/article/10.3847/1538-4357/ab521e

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 9:01 am on April 7, 2020 Permalink | Reply
    Tags: , , Astrophysics, , , , , , Quasar 3C 279, , Telescopes contributing also are the Submillimeter Telescope; and the South Pole Telescope., Telescopes contributing to this result were ALMA; APEX; the IRAM 30-meter telescope; the James Clerk Maxwell Telescope; the Large Millimeter Telescope; the Submillimeter Array., The data analysis to transform raw data to an image required specific computers (or correlators) hosted by the MPIfR in Bonn and the MIT Haystack Observatory.,   

    From ALMA: “Event Horizon Telescope Images of a Black-Hole Powered Jet” 

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    From ALMA

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: pio@eso.org

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Cell phone: +1 (434) 249 3423
    Email: alma-pr@nrao.edu

    1
    2
    Illustration of multiwavelength 3C 279 jet structure in April 2017. The observing epochs, arrays, and wavelengths are noted at each panel. Credit: J.Y. Kim (MPIfR), Boston University Blazar Program (VLBA and GMVA), and Event Horizon Telescope Collaboration.

    Something is Lurking in the Heart of Quasar 3C 279. One year ago, the Event Horizon Telescope (EHT) Collaboration published the first image of a black hole in the nearby radio galaxy Messier 87.

    Mesier 87*, The first image of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    Now the collaboration has extracted new information from the EHT data of the far quasar 3C 279: they observed in the finest detail ever a relativistic jet that is believed to originate from the vicinity of a supermassive black hole. In their analysis, which was led by astronomer Jae-Young Kim from the Max Planck Institute for Radio Astronomy in Bonn, they studied the jet’s fine-scale morphology close to the jet base where highly variable gamma-ray emission is thought to originate. The technique used for observing the jet is called very long baseline interferometry (VLBI). The results are published in the coming issue of “Astronomy & Astrophysics, April 2020.

    The EHT collaboration continues extracting information from the groundbreaking data collected in its global campaign in April 2017. One target of the observations was the quasar 3C 279, a galaxy 5 billion light-years away, in the constellation Virgo that scientists classify as a quasar because a point of light at its center shines ultra-bright and flickers as massive amounts of gases and stars fall into the giant black hole there. The black hole is about one billion times the mass of the Sun, that is, 200 more massive than our Galactic Centre black hole. It is shredding the gas and stars that come near into an inferred accretion disk and we see it is squirting some of the gas back out in two fine fire-hose-like jets of plasma at velocities approaching the speed of light. This tells of enormous forces at play in the center.

    The EHT collaboration continues extracting information from the groundbreaking data collected in its global campaign in April 2017. One target of the observations was the quasar 3C 279, a galaxy 5 billion light-years away, in the constellation Virgo that scientists classify as a quasar because a point of light at its center shines ultra-bright and flickers as massive amounts of gases and stars fall into the giant black hole there. The black hole is about one billion times the mass of the Sun, that is, 200 more massive than our Galactic Centre black hole. It is shredding the gas and stars that come near into an inferred accretion disk and we see it is squirting some of the gas back out in two fine fire-hose-like jets of plasma at velocities approaching the speed of light. This tells of enormous forces at play in the center.

    The interpretation of the observations is challenging. Motions different than the jet direction, and apparently as fast as about 20 times the speed of light are difficult to reconcile with the early understanding of the source, this suggests traveling shocks or instabilities in a bent, possibly rotating jet, which also emits at high energies, such gamma-rays.

    The telescopes contributing to this result were ALMA, APEX, the IRAM 30-meter telescope, the James Clerk Maxwell Telescope, the Large Millimeter Telescope, the Submillimeter Array, the Submillimeter Telescope, and the South Pole Telescope.

    The telescopes work together using a technique called very long baseline interferometry (VLBI). This synchronizes facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope. VLBI allows the EHT to achieve a resolution of 20 micro-arcseconds — equivalent to identifying an orange on Earth as seen by an astronaut from the Moon. The data analysis to transform raw data to an image required specific computers (or correlators), hosted by the MPIfR in Bonn and the MIT Haystack Observatory.

    Anton Zensus, Director at the MPIfR and Chair of the EHT Collaboration Board, stresses the achievement as a global effort: “Last year we could present the first image of the shadow of a black hole. Now we see unexpected changes in the shape of the jet in 3C 279, and we are not done yet. We are working on the analysis of data from the centre of our Galaxy in Sgr A*, and on other active galaxies such as Centaurus A, OJ 287, and NGC 1052. As we told last year: this is just the beginning.”

    Opportunities to conduct EHT observing campaigns occur once a year in early Northern springtime, but the March/April 2020 campaign had to be cancelled in response to the CoViD-19 global outbreak. In announcing the cancellation Michael Hecht, astronomer from the MIT/Haystack Observatory and EHT Deputy Project Director, concluded that: “We will now devote our full concentration to completion of scientific publications from the 2017 data and dive into the analysis of data obtained with the enhanced EHT array in 2018. We are looking forward to observations with the EHT array expanded to eleven observatories in the spring of 2021”.

    Additional Information

    The Event Horizon Telescope international collaboration announced the first-ever image of a black hole at the heart of the radio galaxy Messier 87 on April 10, 2019 by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a new instrument with the highest angular resolving power that has yet been achieved.

    The individual telescopes involved in the EHT collaboration are: the Atacama Large Millimetre Telescope (ALMA), the Atacama Pathfinder EXplorer (APEX), the Greenland Telescope (since 2018), the IRAM 30-meter Telescope, the IRAM NOEMA Observatory (expected 2021), the Kitt Peak Telescope (expected 2021), the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope (LMT), the Submillimeter Array (SMA), the Submillimeter Telescope (SMT), and the South Pole Telescope (SPT).

    The EHT consortium consists of 13 stakeholder institutes; the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universität Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max-Planck-Institut für Radioastronomie, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.

    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 Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large

     
  • richardmitnick 12:53 pm on April 6, 2020 Permalink | Reply
    Tags: "Far stars firmly in sight thanks to telescope teamwork", , , Astrophysics, , , Interferometry- to harness the power of multiple telescopes.   

    From Australian National University: “Far stars firmly in sight thanks to telescope teamwork” 

    ANU Australian National University Bloc

    From Australian National University

    6 April 2020

    1

    Stars far, far away could appear a lot closer when viewed through our telescopes thanks to new research from The Australian National University (ANU).

    The research has also brought the properties of nearby stars into never before seen precision, and could allow us to catch a rare glimpse of the conditions of planets orbiting them in the future.

    PhD researcher Adam Rains used a cutting-edge approach to measure the properties of 16 stars, making them clearer than ever before.

    “To put things in perspective, the measurement precision we achieved is like looking at a dollar coin 4,600 km away and measuring its diameter to the nearest 0.25 mm,” Mr Rains said.

    “We now know the temperature of these stars to a similar level of precision! For example – this is like measuring a 5,000 degree star to within 50 degrees.

    “To do this, we combined the light from multiple telescopes.”

    Mr Rains says ordinarily, features like the size and temperature of stars are very difficult to measure directly.

    “Most stars are simply too far away, and our current telescopes too small for us to study at the level of detail or resolution we have reached here,” he said.

    “The stars we looked at are relatively close in comparison. That’s why this research is so important – so much of our knowledge of stars all over the universe is built upon what we have learnt about the stars closest to us.”

    Several of the stars observed for this study have planets around them – making any information collected about them even more valuable.

    “By knowing things like how big, how hot, and how bright these stars are, we are also better able to figure out what conditions might be like on any planets orbiting them,” Mr Rains said.

    Mr Rains looked at a number of stars like Tau Ceti which have been previously observed by other astronomers, to make sure his results matched up.

    The study was carried out using a method called interferometry to harness the power of multiple telescopes.

    “Interferometry combines light from a set of separate telescopes to increase their resolution beyond any of the individual telescopes – making the whole greater than the sum of its parts,” Mr Rains said

    “Currently the biggest telescopes on the planet have mirrors about 10 metres across. Even larger telescopes are under construction, but there are practical limits on just how big they can get.

    “If you can combine the light from separate telescopes you can achieve the resolution of a much larger telescope – without actually building one. It’s like having a 130m telescope.”

    For this technique to work, you have to make sure the starlight from the telescopes arrives at the camera at exactly the same time.

    This is achieved by having ‘mirror-trains’. Mirrors are placed on carriages that move along a rail system to control when each telescope’s light hits the camera.

    “The further apart your telescopes, the longer the rail system you need, but this technique is the only one that lets us study other stars at such high resolution,” Mr Rains said.

    Mr Rains’ work was based on observations carried out at the Very Large Telescope facility in Chile, operated by the European Southern Observatory.

    ESO VLT 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,

    The research has been published by the Monthly Notices of the Royal 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

    ANU Campus

    ANU is a world-leading university in Australia’s capital city, Canberra. Our location points to our unique history, ties to the Australian Government and special standing as a resource for the Australian people.

    Our focus on research as an asset, and an approach to education, ensures our graduates are in demand the world-over for their abilities to understand, and apply vision and creativity to addressing complex contemporary challenges.

     
  • richardmitnick 2:28 pm on April 4, 2020 Permalink | Reply
    Tags: "Forming the TRAPPIST-1 Exoplanets", , Astrophysics, , , , TRAPPIST-1 is a system of seven Earth-sized worlds orbiting an ultra-cool dwarf star about forty light-years away.   

    From Harvard-Smithsonian Center for Astrophysics: “Forming the TRAPPIST-1 Exoplanets” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

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

    ESO Belgian robotic Trappist-South National Telescope at Cerro La Silla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    TRAPPIST-1 is a system of seven Earth-sized worlds orbiting an ultra-cool dwarf star about forty light-years away. The IRAC camera on Spitzer was used to help discover these seven Earth-sized planets orbiting the star, at least three of them lying in the star’s habitable zone.

    IRAC camera on the Spitzer space telescope

    NASA/Spitzer Infrared Telescope. No longer in service.

    The star, and hence its system of planets, is thought to be about eight billion years old, almost twice as old as our own solar system. For scientists seeking evidence for life elsewhere, the advanced age provides more time for chemistry and evolution to operate than the Earth had. On the other hand, the planets are all close to the star (in fact they are probably tidally locked to the star with one side always facing it), and consequently would have soaked up billions more year’s-worth of high energy radiation from the star’s winds, perhaps adversely affecting any atmospheres they host.

    Nevertheless, the three planets in the habitable zone could have liquid water if they formed with the right composition and/or if water was subsequently deposited on their surfaces. The Kuiper Belt in our solar system is an orbiting disk of comets and small objects that extends roughly from Neptune out to fifty AU from the Sun (one AU being the average Earth-Sun distance). It is thought that comets brought water to the Earth during its youth, and comets in TRAPPIST-1’s Kuiper belt – if there are any – might provide a way to deposit water onto its seven planets. With the right atmospheric conditions, the three planets in the habitable zone might even have liquid water on their surfaces.

    CfA astronomer Luca Matra was a member of a team that used the ALMA submillimeter facility to study the TRAPPIST-1 system to look for signs of an exo-Kuiper belt and clues about the formation of its planets.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    The scientists searched for radiation emitted by dust grains and carbon monoxide gas, but did not find any. The limits were sensitive enough, however, to reach some important conclusions when combined with conservative estimates of the system’s age and evolution. They conclude that probably the TRAPPIST-1 system was born with a planetary disk smaller than forty AU in radius whose mass was less than about twenty Earth-masses, and moreover that very possibly most of the dust grains in the disk were transported inward and used to form the seven planets. The scientists used their modeling code to examine archival ALMA data on the closeby star Proxima Cen and its exoplanetary system.

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    It also showed only upper limits to the dust and gas emission, implying that its young disk was less than about one-tenth as massive as the one that formed our solar system. These results leave the question of early water transport undecided in these systems, but have encouraged the scientists to apply their techniques to younger and closer stellar systems in order to increase their detections and refine their models.

    Science paper:
    MNRAS

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 2:11 pm on April 4, 2020 Permalink | Reply
    Tags: "Astronomers Detect First Double Helium-Core White Dwarf Gravitational Wave Source", , Astrophysics, , ,   

    From Harvard-Smithsonian Center for Astrophysics:”Astronomers Detect First Double Helium-Core White Dwarf Gravitational Wave Source” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    April 3, 2020
    Amy Oliver
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    Fred Lawrence Whipple Observatory
    520-879-4402
    amy.oliver@cfa.harvard.edu

    1

    Scientists at the Center for Astrophysics | Harvard & Smithsonian today announced the detection of J2322+0509, a detached binary white dwarf composed of two helium-core stars with a short orbital period. It is the first gravitational wave source of its kind ever detected.

    “Theories predict that there are many double helium-core white dwarf binaries out there,” said Dr. Warren Brown, CfA astronomer and lead author on the study. “This detection provides an anchor for those models, and for doing future experiments so that we can find more of these stars and determine their true numbers.”

    The star will be used for verification on the much-anticipated LISA (Laser Interferometer Space Antenna) gravitational wave observatory, planned for launch in 2034, said Dr. Mukremin Kilic, from the University of Oklahoma, and a co-author on the study. “Verification binaries are important because we know that LISA will see them within a few weeks of turning on the telescopes,” said Kilic. “There’s only a handful of LISA sources that we know of today. The discovery of the first prototype of a new class of verification binary puts us well ahead of where anyone could have anticipated.”

    Early on, scientists found J2322+0509 a challenge to study, collecting critical information about the class of stars that will shape future scientific results through multiple avenues. Optical light curve studies yielded no result, said Brown. “This binary had no light curve. We couldn’t detect a photometric signal because there isn’t one.” Spectroscopic studies, however, shaped the story of a difficult-to-detect yet scientifically important binary system, and revealed its orbital motion.

    “We’re finding that the binaries that might be the hardest to detect may actually be the strongest sources of gravitational waves,” said Brown. “This binary was difficult to detect because it is oriented face-on to us, like a bull’s eye, rather than edge-on. Remarkably, the binary’s gravitational waves are 2.5 times stronger at this orientation than if it were orientated edge-on like an eclipsing binary.”

    The pair also held another surprise for researchers. With an orbital period of 1201 seconds, or just over 20 minutes, the pair is confirmed as having the third shortest period of all known detached binaries. “This pair is at the extreme end of stars with short orbital periods,” said Brown. “And the orbit of this pair of objects is decaying. The gravitational waves that are being emitted are causing the pair to lose energy; in six or seven million years they will merge into a single, more-massive white dwarf.”

    Spectroscopic data for J2322+0509 was collected using the MMT telescope at the Fred Lawrence Whipple Observatory in Amado, Arizona; the Magellan Baade telescope at the Las Campanas Observatory in Chile; and, the Gemini-North telescope on Mauna Kea, Hawaii.

    CfA U Arizona Fred Lawrence Whipple Observatory Steward Observatory MMT 6.5-m Telescope at the summit of Mount Hopkins near Tucson, Arizona, USA, Altitude 2,616 m (8,583 ft)

    Carnegie 6.5 meter Magellan Baade and Clay Telescopes located at Carnegie’s Las Campanas Observatory, Chile. over 2,500 m (8,200 ft) high

    Frederick C Gillett Gemini North Telescope Maunakea, Hawaii, USA, Altitude 4,213 m (13,822 ft)

    The results of the study will be published in Astrophysical Journal Letters.

    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 Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 10:19 am on April 4, 2020 Permalink | Reply
    Tags: "Peering Into the Atmosphere of the Hottest Planet Known", , , Astrophysics, , , , Kilodegree Extremely Little Telescope (KELT) system   

    From AAS NOVA: “Peering Into the Atmosphere of the Hottest Planet Known” KELT-9b 

    AASNOVA

    From AAS NOVA

    3 April 2020
    Susanna Kohler

    1
    Artist’s impression of KELT-9b, the hottest planet known, and its escaping atmosphere. [NASA/JPL-Caltech]

    As the ultra-hot Jupiter KELT-9b blazes across the face of its host star, we have an excellent opportunity to examine its scalding atmosphere. A new study now reports on what we’ve found.

    A Passing Glance

    In our efforts to learn more about worlds beyond our solar system, atmospheres provide a critical key. Characterizing the atmospheres of exoplanets can provide us with insight into the planets’ compositions and climates, their evolution, and even — with some potential caveats — their habitability.

    1
    As a star’s light filters through a planet’s atmosphere on its way to Earth, the atmosphere absorbs certain wavelengths depending on its composition. [European Southern Observatory]

    In particular, transiting exoplanets provide us with a unique opportunity. As a planet passes in front of its host star, we briefly observe the star’s light filtering through the planet’s atmosphere. By exploring the spectrum of that light, not only can we identify the presence of specific atoms and molecules in the planet’s atmosphere, but we can also learn more about where they are and what the atmospheric properties are at those locations.

    In a new study led by Jake Turner (Cornell University), a team of scientists digs deep into such a transmission spectrum for the exoplanet KELT-9b.

    Not Exactly Temperate

    KELT-9b is an extreme world. Clocking in with a dayside temperature of more than 4,500 K (~7,600 °F), it is the hottest planet known — hotter than many stars! This ultra-hot Jupiter orbits at a mere 0.035 AU from its scalding A- or B-type host star, whizzing around its host in just 1.5 days.

    The intense radiation bombarding KELT-9b almost certainly takes a toll: this energetic light should dissociate molecules into their component atoms and ionize metals in the hot atmosphere, and it may inflate the envelope of hydrogen gas around the planet to the point where the hot gas escapes.

    3
    Observed and modeled Hα (top) and Ca II (bottom three) spectral lines in the atmosphere of the ultra-hot Jupiter KELT-9b. [Adapted from Turner et al. 2020]

    Turner and collaborators explore the extreme conditions in KELT-9b’s atmosphere with high-resolution transmission spectra taken with the CARMENES instrument on the Calar Alto 3.5-m telescope in Spain.

    CARMENES spectrograph, mounted on the Calar Alto 3.5 meter Telescope


    Calar Alto 3.5 meter Telescope, located in Almería province in Spain on Calar Alto, a 2,168-meter-high (7,113 ft) mountain in Sierra de Los Filabres

    Detecting Atmospheric Thermometers

    The authors find absorption lines indicating the presence of ionized calcium, Ca II, in KELT-9b’s atmospheric spectra; this is just the second time that Ca II has been observed in a hot Jupiter’s atmosphere. They also find prominent Hα absorption — evidence that confirms the existence of an extended envelope of hydrogen surrounding the irradiated planet.

    By modeling the spectra they obtain for KELT-9b, Turner and collaborators are able to identify the pressures, altitudes, and temperatures at which these spectral lines form in the atmosphere. They find that the Ca II lines probe the atmosphere at an altitude of about 1.32–1.40 times the planet’s radius. The Hα line provides information from higher up, at 1.44 planetary radii.

    Together, these absorption lines act as atmospheric thermometers, providing a picture of KELT-9b’s atmospheric temperature profile and yielding insight into the energy that enters and leaves the planet’s atmosphere.

    These results demonstrate the power of this technique, revealing the remarkable wealth of information we can glean from some distant starlight filtered through the atmosphere of an extreme world.

    Citation

    “Detection of Ionized Calcium in the Atmosphere of the Ultra-hot Jupiter KELT-9b,” Jake D. Turner et al 2020 ApJL 888 L13.
    https://iopscience.iop.org/article/10.3847/2041-8213/ab60a9

    ______________________________________________
    From JPL-Caltech

    KELT-9b will stay firmly categorized among the uninhabitable worlds. Astronomers became aware of its extremely hostile environment in 2017, when it was first detected using the Kilodegree Extremely Little Telescope (KELT) system – a combined effort involving observations from two robotic telescopes, one in southern Arizona and one in South Africa.

    4
    KELT South robotic telescope, Southerland, South Africa, jointly operated by Ohio State, Vanderbilt and Lehigh universities.

    5
    KELT Kilodegree Extremely Little Telescope at WINER Observatory in Arizona, USA c J.Peppe, operated by Ohio State, Vanderbilt and Lehigh universities

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
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