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  • richardmitnick 8:10 am on October 7, 2022 Permalink | Reply
    Tags: "How satellites harm astronomy - what’s being done", , , , , , , International Telecommunication Union, NOIRLab, , Square Kilometer Array Observatory (SKAO),   

    From “EarthSky” : “How satellites harm astronomy – what’s being done” 

    1

    From “EarthSky”

    10.6.22
    Kelly Kizer Whitt

    1
    Artist’s concept shows the 30,000 planned satellites from the Starlink Generation 2 constellation as of 2022. Different sub-constellations are in different colors. Learn more about how mega constellations of satellites harm astronomy. Image via The European Southern Observatory [La Observatorio Europeo Austral] [Observatoire européen austral][Europäische Südsternwarte](EU)(CL).

    You may have heard the growing complaints from astronomers as companies such as SpaceX add more satellites to our sky. Astronomers are not against the communication networks that the satellites provide, but they have valid concerns for the future of ground-based explorations of the universe. And there is only so much astronomers can do on their own to mitigate the problem. A report from the 2021 conference for Dark and Quiet Skies stated:

    “The advantages to society that the communication constellations are offering cannot be disputed, but their impact on the pristine appearance of the night sky and on astronomy must be considered with great attention because they affect both the cultural heritage of humanity and the progress of science.”

    How satellites harm astronomy: The problem with increasing satellites

    Astronomers face a variety of problems with the increasing numbers of satellites filling low-Earth orbit. Optical and near-infrared telescopes feel the impacts from these mega constellations. Some of the biggest are on wide-field surveys, longer exposures and evening and morning twilight observations when sunlight reflects off the satellites. The European Southern Observatory, the European Space Organization, reported these findings from a 2021 study [Astronomy & Astrophysics(below)]:

    “The effect is more pronounced for long exposures, up to three percent of which may be ruined during twilight. The study also found that the greatest impact of new satellite constellations will be on wide-field surveys made by telescopes such as the US National Science Foundation’s Vera C. Rubin Observatory. Up to 30-50 percent of twilight observations being seriously impacted.”

    And because we’re talking about scientists, of course they’ve officially started studying the issue. Studies in 2020 [ Astronomy and Astrophysics (below)] and 2021 [Astronomy & Astrophysics (below)] showed the impact on optical and near-infrared telescopes. They found that telescopes such as the Very Large Telescope (VLT) and the future Extremely Large Telescope (ELT) will be “moderately affected” by new satellite mega constellations.

    Some telescopes, such as the Rubin Observatory under construction in Chile, will experience greater impacts. These telescopes scan wide areas quickly. This makes them crucial in spotting supernovae or potentially dangerous asteroids.

    The impact on radio astronomy

    Radio astronomy has its own particular concerns. Radio telescopes don’t look in the visible wavelengths of the electromagnetic spectrum, so it’s not the same “visibility” issue. For radio telescopes, the main problem is with the signals the satellites transmit down to Earth. Plus, radio telescopes aren’t only looking at dim lights in the night. They’re looking at the sky 24/7. So, satellites are a problem every hour of the day, not just at twilight.

    But there’s more. A satellite’s signal is much, much stronger than the faint background sources that radio astronomers study. And a satellite doesn’t have to pass right in front of the object of study to cause interference. Satellite sources in a radio telescope’s “peripheral vision” also interfere.

    The European Southern Observatory (ESO) described the potential impact of satellites on radio astronomy:

    “They amount to hundreds of radio transmitters above the observatory’s horizon, which will affect the measurements made by our highly sensitive radio telescopes.”

    Radio astronomy has some protection against interference. Radio astronomers call this spectrum management, and the Radio Communication Sector of the International Telecommunication Union (ITU-R) create regulations that help protect astronomers studying certain frequency bands and wavelength ranges. But the recent large constellations of telecommunication satellites pose new threats.

    One recommendation is for satellite designs that avoid direct illumination of radio telescopes and radio-quiet zones. Also, the cumulative background electromagnetic noise created by satellite constellations should be kept below the limit already agreed to by the ITU.

    Philip Diamond of the Square Kilometer Array Observatory (SKAO) summed up the issue:

    “The deployment of thousands of satellites in low-Earth orbit in the coming years will inevitably change this landscape by creating a much larger number of fast-moving radio sources in the sky, which will interfere with humanity’s ability to explore the universe.”

    What can visual astronomers do?

    It would be great if a computer program could quickly eliminate all the satellites trails or interference from astronomers’ data. But it’s not quite that easy. One recent report outlined the problem of low-Earth orbit satellites on images:

    “They leave traces of their transit on astronomical images, significantly decreasing the scientific usability of the collected data. Post-processing of the affected images only partially remedies the problem: the brighter trails may saturate the detectors, making portions of images unusable, while the removal of the fainter trails leaves residual effects that seriously affect important scientific programs, as, for example, statistical, automated surveys of faint galaxies.”

    But there are some things astronomers could do, and have been doing thus far. They can avoid observing where satellites will pass, limit observations to areas of the sky that are in Earth’s shadow and close the shutter precisely when a satellite crosses the field of view. This all takes a lot of knowledge of the paths of thousands of satellites and plenty of pre-planning. Obviously, these are not realistic possibilities for many situations.

    What can satellite operators do?

    Another way to mitigate the problem is for satellite operators to adjust their designs (for example, darkening the satellite). They can also operate the satellites in a way that would raise their orbits out of vision of the optical telescopes, deorbit satellites that are no longer functioning, as well as other considerations for minimizing disruption. In several cases, the satellite operators have shown willingness to cooperate on this.

    Unfortunately, the companies planning these mega satellite constellations did not warn astronomers in advance. So many of these satellites were already filling the skies without any restrictions as astronomers scrambled to figure out how to save their observations and lessen the impact. Their efforts led to the creation of a new center that is collecting data from the community, astronomers and the general public, among others, to learn more about the effects on the night sky.

    Official efforts to reduce harm from satellites

    In June 2022, the International Astronomical Union (IAU), together with the National Science Foundation’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab) and SKAO, opened the Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS). The center highlights the dramatically increased risk of interference from low-Earth orbit satellites – both planned and already in orbit – that provide broadband services. On their website, you can see a running total of the number of operational constellation satellites (2,994) and the number of planned constellation satellites (431,713), among other stats.

    Co-director Connie Walker from NOIRLab said:

    “Three years ago SpaceX launched the first 60 Starlink satellites. The number of satellites from this and other companies is increasing exponentially and impacting the field of astronomy. During the last two years, four key workshops identified issues and recommended mitigation solutions with the help of astronomers, satellite industry folk, space lawyers and people from the general community worldwide.”

    In the peer-reviewed journal Air & Space Law [below], scientists at ESO published a study in September 2021 extensively warning of the dangers of unlimited satellites on astronomy. They’re trying to address satellite constellations’ impact on astronomy. They’re making efforts to coordinate solutions so both satellites and observational astronomy can continue developing without harmful interference.

    A reminder of what we’re losing when satellites harm astronomy

    One of ESO’s studies estimated that in the future, up to 100 satellites could be visible to the unaided eye during twilight. Imagine how that will change your own view of the night sky. Then imagine if your profession depended upon seeing what is beyond the satellites. How will we learn about the universe or detect potential threats to Earth?

    The IAU created the Dark and Quiet Skies Working Group. As Debra Elmegreen, IAU President, summed up:

    “Interference of our view of the sky caused by ground-based artificial lights, optical and infrared trails of satellite constellations and radio transmission on the ground and in space is an existential threat to astronomical observations. Viewing the night sky has been culturally important throughout humanity’s history, and dark skies are important for wildlife as well.”

    Science papers:
    Astronomy & Astrophysics
    Astronomy and Astrophysics 2020
    Astronomy & Astrophysics 2021
    Air & Space Law 2021
    See the science papers for instructive material.

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 12:55 pm on January 14, 2021 Permalink | Reply
    Tags: "Shining a New Light on Dark Energy", , , , , NOIRLab, The Dark Energy Survey is a global collaboration that includes Fermi National Accelerator Laboratory (Fermilab); the National Center for Supercomputing Applications (NCSA); and NSF’s NOIRLab.   

    From NOIRLab: “Shining a New Light on Dark Energy” 

    NOIRLab composite

    From NOIRLab

    14 January 2021

    Rich Kron
    Dark Energy Survey spokesperson
    University of Chicago / Fermilab
    Email: rich@astro.uchicago.edu

    Robert Nikutta
    NSF’s NOIRLab
    Cell: +1 919 633 5406
    Email: robert.nikutta@noirlab.edu

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    Dark Energy Survey releases catalog of 700 million objects.

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    Elliptical galaxy NGC 474 — excerpt from the Dark Energy Survey. Credit: DES/CTIO/NOIRLab/NSF/DOE/AURA
    Acknowledgments: Image processing: DES, Jen Miller (Gemini Observatory/NSF’s NOIRLab), Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.

    DR2 is the second release of images and object catalogs from the Dark Energy Survey (DES). It is the culmination of over half a decade of astronomical data collection and analysis, with the ultimate goal of understanding the accelerating expansion rate of the Universe and the phenomenon of dark energy that is thought to be responsible for the expansion. The Dark Energy Survey is a global collaboration that includes Fermi National Accelerator Laboratory (Fermilab), the National Center for Supercomputing Applications (NCSA), and NSF’s NOIRLab.

    Including a catalog of nearly 700 million astronomical objects, DR2 builds on the 400 million objects cataloged with the Survey’s previous data release (DR1), and also improves on it by refining calibration techniques, which, with the deeper combined images from DR2, leads to improved estimates of the amount and distribution of matter in the Universe. It is one of the largest astronomical catalogs released to date.

    Astronomical researchers around the world can access these unprecedented data and mine them to make new discoveries about the Universe, complementary to the studies being carried out by the Dark Energy Survey collaboration. The full data release can be accessed here and is available to scientists and the public to explore.

    One early result relates to the construction of a catalog of RR Lyrae pulsating stars, which tell scientists about the region of space beyond the edge of our Milky Way. In this area nearly devoid of stars, the motion of the RR Lyrae stars hints at the presence of an enormous “halo” of invisible dark matter, which may provide clues to how our galaxy was assembled over the last 12 billion years.

    Caterpillar Project A Milky-Way-size dark-matter halo and its subhalos circled, an enormous suite of simulations . Griffen et al. 2016.

    In another result, DES scientists used the extensive DR2 galaxy catalog, along with data from the LIGO gravitational wave experiment, to estimate the location of a black hole merger and, independent of other techniques, infer the value of the Hubble constant, a key cosmological parameter.

    MIT /Caltech Advanced aLigo .

    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA.

    Caltech/MIT Advanced aLigo detector installation Hanford, WA, USA.

    VIRGO Gravitational Wave interferometer, near Pisa, Italy.

    VIRGO Gravitational Wave interferometer, near Pisa, Italy.

    Combining their data with other surveys, DES scientists have also been able to generate a detailed map of the Milky Way’s dwarf satellites, giving researchers insight into how our own galaxy was assembled and how it compares with cosmologists’ predictions.

    The detailed precision cosmology constraints based on the full six-year DES dataset will come out over the next two years.

    DES was conceived to map hundreds of millions of galaxies and to chart the size of the expanding Universe as it accelerates under the influence of dark energy. DES has produced the largest and most accurate dark matter map from galaxy weak lensing to date.

    Covering 5000 square degrees of the southern sky, the survey data enable many other investigations in addition to those targeting dark energy, covering a vast range of cosmic distances — from discovering new nearby Solar System objects to investigating the nature of the first star-forming galaxies in the early Universe.

    “This is a momentous milestone. For six years, the Dark Energy Survey collaboration took pictures of distant celestial objects in the night sky. Now, after carefully checking the quality and calibration of the images captured by the Dark Energy Camera, we are releasing this second batch of data to the public,” said DES Director Rich Kron of Fermilab and the University of Chicago. “We invite professional and amateur scientists alike to dig into what we consider a rich mine of gems waiting to be discovered.”

    The primary tool used to collect these images, the Dark Energy Camera (DECam), is mounted on the National Science Foundation-funded Víctor M. Blanco 4-meter Telescope , part of the Cerro Tololo Inter-American Observatory (CTIO) in the Chilean Andes, a Program of NSF’s NOIRLab.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOIRLab NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

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

    Each week from 2013 to 2019, DECam collected thousands of images of the southern sky, unlocking a trove of potential cosmological insights.

    Once captured, these images (and the large amount of data surrounding them) were transferred to NCSA for processing via the DES Data Management (DESDM) project. Using the Blue Waters supercomputer at NCSA, the Illinois Campus Cluster, and computational systems at Fermilab, NCSA prepares calibrated data products for research and public consumption. It took approximately four months to process one year’s worth of data into a searchable, usable catalog. The DES DR2 is hosted at the Community Science and Data Center (CSDC), a Program of NSF’s NOIRLab. CSDC provides software systems, user services, and development initiatives to connect and support the scientific missions of NOIRLab’s telescopes, including the Blanco Telescope at CTIO.

    “Because astronomical datasets today are so vast, the cost of handling them is prohibitive for individual researchers or most organizations,” said Robert Nikutta, Project Scientist for Astro Data Lab at CSDC. “CSDC provides open access to big astronomical datasets like DES DR2, and the necessary tools to explore and exploit them — then all it takes is someone from the community with a clever idea to discover new and exciting science.”

    The DES DR2 will be featured in two online sessions at the 237th meeting of the American Astronomical Society: NOIRLab’s Data Services: A Practical Demo Built on Science with DES DR2 on Thursday 14 January at 4:10 pm EST, and Dark Energy Survey: New Results and Public Data Release 2 on Friday 15 January at 12:00 pm EST.

    See the full article here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 9:46 am on January 14, 2021 Permalink | Reply
    Tags: "Mapping Our Sun’s Backyard", Astronomers and citizen scientists produce the most complete 3D map of cool brown dwarfs in the Sun’s neighborhood., , , Backyard Worlds citizen science project., Backyard Worlds: Planet 9 collaboration, , Brown dwarfs are sometimes referred to as “failed stars.”, , , LBNL/DESI spectroscopic instrument, NOIRLab   

    From NOIRLab: “Mapping Our Sun’s Backyard” 

    NOIRLab composite

    From NOIRLab

    13 January 2021

    Aaron Meisner
    Astronomer at NSF’s NOIRLab
    Cell: +1 650 714 8643
    Email: aaron.meisner@noirlab.edu

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    Astronomers and citizen scientists produce the most complete 3D map of cool brown dwarfs in the Sun’s neighborhood.

    Artist’s concept of a Brown dwarf [not quite a] star. NASA/JPL-Caltech.

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    Brown dwarfs in the Sun’s neighborhood.


    CosmoView Episode 20: Mapping Our Sun’s Backyard.

    Astronomers have curated the most complete list of nearby brown dwarfs to date thanks to discoveries made by thousands of volunteers participating in the Backyard Worlds citizen science project. The list and 3D map of 525 brown dwarfs — including 38 reported for the first time — incorporate observations from a host of astronomical instruments including several NOIRLab facilities. The results confirm that the Sun’s neighborhood appears surprisingly diverse relative to other parts of the Milky Way Galaxy.

    Mapping out our own small pocket of the Universe is a time-honored quest within astronomy, and the results announced today have added to this long-running effort by cataloging the locations of more than 500 cool brown dwarfs in the vicinity of the Sun. An international team of astronomers — assisted by the legions of volunteer citizen scientists in the Backyard Worlds: Planet 9 collaboration — have announced an unprecedented census of 525 cool brown dwarfs within 65 light-years of the Sun, including 38 new discoveries. By determining the distances to all the objects in the census, astronomers have been able to build a 3D map of the distribution of cool brown dwarfs in the Sun’s local neighborhood.

    This breakthrough relied on novel datasets published by the DESI Legacy Imaging Surveys, which blend huge quantities of astronomical data from a variety of sources: archival images from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (KPNO) and the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), which are Programs of NSF’s NOIRLab, plus critical sky maps from NASA’s Wide-field Infrared Survey Explorer (WISE).

    LBNL/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory, in 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).

    NOIRLab NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, at Kitt Peak National Observatory, in 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).

    Kitt Peak National Observatory 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.

    NOIRLab NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet.

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

    NASA/WISE NEOWISE Telescope.

    These powerful survey datasets were combined with new distance measurements from the NASA Spitzer Space Telescope to create the best three-dimensional map of the Sun’s local neighborhood to date.

    NASA/Spitzer Infrared telescope no longer in service. Launched in 2003 and retired on 30 January 2020. Credit: NASA.

    Brown dwarfs are sometimes referred to as “failed stars.” They are thought to form the way stars do, but they do not become massive enough to trigger nuclear fusion in their cores. Their faintness and relatively small sizes make them difficult to identify without careful analysis of data from sensitive telescopes — meaning that many have gone undiscovered until now. However, by finding and studying brown dwarfs, astronomers can learn more about star formation and also about planets around other stars.

    “Brown dwarfs are the low-mass byproducts of the process that forms stars, yet the least massive of them have many characteristics in common with exoplanets,” says J. Davy Kirkpatrick, California Institute of Technology scientist and lead author of the research paper. “They’re exoplanet laboratories, but since they are usually by themselves and lack the complications caused by a blinding host sun, they’re much easier to study.”

    To help identify elusive brown dwarfs in massive datasets, astronomers enlisted the help of the Backyard Worlds collaboration, a worldwide network of more than 100,000 citizen scientists.[1] Astro Data Lab at NOIRLab’s Community Science and Data Center (CSDC) was instrumental in providing these volunteers with data, allowing citizen scientists to easily hunt through the astronomical archives in search of brown dwarf candidates. The Backyards Worlds project announced the discovery of almost 100 nearby cool brown dwarfs in August last year, and today’s announcement is a continuation of their work.

    “The Backyard Worlds project shows that the general public can play an important role in cutting-edge astronomy,” commented NOIRLab scientist Aaron Meisner, co-author of this study and co-founder of Backyard Worlds. “Volunteers ranging from high school students to retired engineers are helping uncover groundbreaking discoveries lurking in existing telescope data.”

    One of the most intriguing results of this study is that it provides more evidence that the Sun’s immediate neighborhood (within roughly 7 light-years) is rather unusual. While most stars in the Milky Way are red dwarfs, earlier results revealed that the Sun’s closest neighbors are much more diverse, with different types of objects, from Sun-like stars to Jupiter-like brown dwarfs, appearing in roughly equal numbers.[2] The new results add to this disparity by turning up no more extremely cold brown dwarfs like our close-by neighbor WISE 0855, the coldest known brown dwarf, even though the team expected to find at least several more within 65 light-years of the Sun, given the new study’s sensitivity.

    This result hints at the possibility that yet more cold brown dwarfs have so far eluded detection. “Thanks to the efforts of volunteers around the world, we have a better idea than ever of the objects in our cosmic backyard,” concluded Meisner. “But we suspect that more of the Sun’s cold and close neighbors still await discovery within our vast data archives.”
    Notes

    [1] Backyard Worlds: Planet 9 is hosted by Zooniverse.
    [2] Stars and brown dwarfs are classified by their temperature and other spectral characteristics using letters of the alphabet. For example, our Sun is a G star, a K star is considered an orange dwarf star, and M stars are often called “red dwarfs,” while brown dwarfs are classified as L, T, and Y dwarfs. Earlier studies have revealed that, collectively, the four nearest star systems to the Sun include one G-dwarf star, one K dwarf, two M dwarfs, one L dwarf, one T dwarf, and one Y dwarf.

    More information

    This research was presented in the paper The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs to appear in The Astrophysical Journal Supplement.

    The team is composed of J. Davy Kirkpatrick (California Institute of Technology), Christopher R. Gelino (California Institute of Technology), Jacqueline K. Faherty (American Museum of Natural History), Aaron M. Meisner (NSF’s NOIRLab), Dan Caselden (Gigamon Applied Threat Research), Adam C. Schneider (US Naval Observatory, George Mason University), Federico Marocco (California Institute of Technology), Alfred J. Cayago (University of California Riverside), R. L. Smart (Istituto Nazionale di Astrofisica, Italy), Peter R. Eisenhardt (Jet Propulsion Laboratory), Marc J. Kuchner (NASA Goddard Space Flight Center), Edward L. Wright (University of California Los Angeles), Michael C. Cushing (University of Toledo), Katelyn N. Allers (Bucknell University), Daniella C. Bardalez Gagliuffi (American Museum of Natural History), Adam J. Burgasser (University of California, San Diego), Jonathan Gagné (Université de Montréal, Canada), Sarah E. Logsdon (NSF’s NOIRLab), Emily C. Martin (University of California, Santa Cruz), James G. Ingalls (California Institute of Technology), Patrick J. Lowrance (California Institute of Technology), Ellianna S. Abrahams (University of California, Berkeley), Christian Aganze (University of California, San Diego), Roman Gerasimov (University of California, San Diego), Eileen C. Gonzales (Cornell University), Chih-Chun Hsu (University of California, San Diego), Nikita Kamraj (California Institute of Technology), Rocio Kiman, (American Museum of Natural History and City University of New York), Jon Rees (University of California, San Diego), Christopher Theissen (University of California, San Diego), Kareem Ammar (Pasadena Polytechnic School), Nikolaj Stevnbak Andersen (Sygehus Lillebalt, Denmark), Paul Beaulieu (Backyard Worlds: Planet 9), Guillaume Colin (Backyard Worlds: Planet 9), Charles A. Elachi (St. Francis High School), Samuel J. Goodman (Backyard Worlds: Planet 9), Léopold Gramaize (Backyard Worlds: Planet 9), Leslie K. Hamlet (Backyard Worlds: Planet 9), Justin Hong (Pasadena High School), Alexander Jonkeren (Backyard Worlds: Planet 9), Mohammed Khalil (Lebanon International College and Stanford University), David W. Martin (Backyard Worlds: Planet 9), William Pendrill (Backyard Worlds: Planet 9), Benjamin Pumphrey (Augusta Psychological Associates), Austin Rothermich (University of Central Florida), Arttu Sainio (Backyard Worlds: Planet 9), Andres Stenner (Backyard Worlds: Planet 9), Christopher Tanner (Backyard Worlds: Planet 9), Melina Thévenot (Backyard Worlds: Planet 9), Nikita V. Voloshin (Backyard Worlds: Planet 9), Jim Walla (Backyard Worlds: Planet 9), Zbigniew Wedracki (Backyard Worlds: Planet 9), and the Backyard Worlds: Planet 9 Collaboration.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 11:58 pm on January 13, 2021 Permalink | Reply
    Tags: "Building a Giant 2D Map of the Universe to Prepare for the Largest 3D Map", , , , , , , , NOIRLab   

    From DOE’s Lawrence Berkeley National Laboratory: “Building a Giant 2D Map of the Universe to Prepare for the Largest 3D Map” 

    From DOE’s Lawrence Berkeley National Laboratory

    January 13, 2021
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 520-0843

    This video describes the monumental effort that went into constructing a 2D map of the universe to prepare for the Dark Energy Spectroscopic Instrument, which will produce the largest-ever 3D map of the universe. The final data release for the preparation of this 2D map, known as Data Release 9 or DR9, is scheduled to be distributed Jan. 13. Credit: Marilyn Sargent/Lawrence Berkeley National Laboratory.

    Before DESI, the Dark Energy Spectroscopic Instrument, can begin its 5-year mission from an Arizona mountaintop to produce the largest 3D sky map yet, researchers first needed an even bigger 2D map of the universe.

    LBNL/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory, in 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).

    NOIRLab NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, at Kitt Peak National Observatory, in 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).

    The 2D map, pieced together from 200,000 telescope images and several years of satellite data, lacks information about galaxy distances, and DESI will supply this and provide other useful details by measuring the color signatures and “redshift” of galaxies and quasars in its survey. Objects’ redder colors provide telltale information about their distance from Earth and about how quickly they are moving away from us – and this phenomenon is known as redshift.

    In the end, this 2D map of the universe is the largest ever, based on the area of sky covered, its depth in imaging faint objects, and its more than 1 billion galaxy images.

    The ambitious, 6-year effort to capture images and stitch them together for this 2D map – which involved 1,405 observing nights at three telescopes on two continents and years of data from a space satellite, an upgraded camera to image incredibly faint and distant galaxies, 150 observers and 50 other researchers from around the world. The effort also required 1 petabyte of data – enough to store 1 million movies – and 100 million CPU hours at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC).

    2D map sets the stage for DESI observations, with a goal to solve dark energy mystery

    “This is the biggest map by almost any measure,” said David Schlegel, co-project scientist for DESI who led the imaging project, known as the DESI Legacy Imaging Surveys. Schlegel is a cosmologist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), which is the lead institution for the international DESI collaboration.

    The map covers half of the sky, and digitally sprawls over 10 trillion pixels, which is equivalent to a mosaic of 833,000 high-res smartphone photos. The DESI collaboration has about 600 participating scientists from 54 institutions around the world.

    Publicly viewable at legacysurvey.org/viewer, the Sky Viewer map includes 2 billion objects – more than half of which are galaxies – and numerous clickable filters to select from specific object types or surveys. Some of the objects are individually labeled, and viewers can choose to display constellations, for example, and galaxies and quasars that will be imaged by DESI. Quasars are among the brightest objects in the universe, with supermassive black holes at their center that emit powerful jets of matter.

    1
    A spiral galaxy, viewed with the Sky Viewer tool at legacysurvey.org/viewer. Sky Viewer uses data from DESI’s 2D mapping effort and from satellite imagery. Credit: DESI Legacy Imaging Surveys.

    DESI is equipped with an array of 5,000 swiveling, automated robots, each toting a thin fiber-optic cable that will be pointed at individual objects. These cables will gather the light from 35 million galaxies and 2.4 million quasars during the five years of DESI observations.

    DESI will collect and transmit data from these measurements to Berkeley Lab’s NERSC from Kitt Peak. Researchers at NERSC have already prepared for this incoming data by identifying which data-processing tasks would take up the most computing time and improving the code to speed up these tasks on the center’s current- and next-generation supercomputers. “In the end, we increased processing throughput five to seven times, which was a big accomplishment – bigger than I expected,” said Laurie Stephey, a data analytics engineer at NERSC who played a key role in the effort.

    The primary purpose of compiling the 2D map data is to identify these galaxy and quasar targets for DESI, which will measure their light to pinpoint their redshift and distance. This will ultimately provide new details about mysterious dark energy that is driving the universe’s accelerating expansion.

    Nathalie Palanque-Delabrouille, DESI co-spokesperson and a cosmologist at the French Alternative Energies and Atomic Energy Commission (CEA), noted that the expansion rate has evolved, and there are many unanswered questions about the changes in this rate.

    “Our universe had a surprising history,” she explained. “During the first half of its life, its expansion was driven mostly by the dark matter it contains.” Dark matter is unknown matter, making up 85 percent of all matter in the universe and so far only observed indirectly through its gravitational effects on normal matter.

    “However, in the past 7 billion years the expansion of our universe has been gradually accelerating under the influence of a mysterious dark energy,” she added, “and the goal of DESI is to precisely clarify this overall picture by unveiling what dark energy is.”

    Palanque-Delabrouille has been involved in the effort to pick targets for DESI to observe from the surveys’ data. She noted that DESI will gather light from a mix of galaxies at several distances, including bright galaxies that are within 4 billion light years of Earth, so-called red galaxies that allow us to see back to 8 billion years ago, very young blue galaxies or “emission-line” galaxies that will go further back 10 billion years ago, and ultimately quasars, which are so bright they can be seen up to 12 billion light-years away.

    “Having managed to collect and process these imaging data is really a major achievement. DESI wouldn’t be getting anywhere without such large imaging surveys,” she said.

    Software guides observing plan, and standardizes and stitches imaging data.

    Piecing together all of the DESI surveys’ images to create a seamless sky map was no trivial task, Schlegel explained. “One of the goals is to get a really uniform image by stitching together multiple observations,” he said. “We started out scattershot. And cameras do have gaps – they miss stuff. Part of the challenge here was planning the observing program so that you could fill in all of the gaps – that was a huge logistical challenge. You have to make sure it is as homogeneous as possible.”

    The three surveys that comprise the DESI Legacy Imaging Surveys conducted imaging in three different colors, and each survey took three separate images of the same sky areas to ensure complete coverage. This new, ground-based imaging data was also supplemented by imaging data from NASA’s Wide-field Infrared Survey Explorer (WISE) satellite mission, which collected space images in four bands of infrared light.

    For the Legacy Imaging Surveys’ data-taking effort, Schlegel designed a code, improved over time, that helped to calculate the best approach and timing for capturing the best images to completely cover half of the sky, considering hours of darkness, weather, exposure time, planetary and satellite paths, and moon brightness and location, among other variables.

    Dustin Lang, DESI imaging scientist at the Perimeter Institute for Theoretical Physics in Canada, played a key role in standardizing all of the imaging data from ground- and sky-based surveys and stitching it together.

    In some images, Lang noted, “the sky might be really stable and calm,” while on another night “we might have light clouds or just a turbulent atmosphere that causes blurring in the images.” His challenge: to develop software that recognized the good data without diluting it with the bad data. “What we wanted to think about is what the stars and galaxies looked like above the atmosphere,” he said, and to make sure the images matched up even when they were taken under different conditions.

    Lang created “The Tractor,” a so-called “inference-based” model of the sky, to compare with data for the shape and brightness of objects imaged by different surveys and to select the best fit. The Tractor drew heavily upon supercomputer resources at Berkeley Lab’s NERSC to process the Legacy Imaging Surveys’ data and ensure its quality and consistency.

    It was Lang, too, who recognized the potential popularity of the viewing tool created for the imaging data – which was adapted from street-mapping software – and brought it to the public as the Sky Viewer interactive map.

    The viewing tool, he noted, was originally used by DESI researchers to check data discrepancies in the surveys’ images. It “transformed the way our team interacted with the data. It suddenly felt a lot more real that we could just scroll around the sky and explore individual problems with our data. It turned out to be surprisingly powerful.”

    Imaging data from 3 surveys seeds other science research

    Arjun Dey, the DESI project scientist for the National Science Foundation’s NOIRLab, which includes the Kitt Peak National Observatory site where DESI is situated, was a major contributor to two of the three imaging surveys, serving as the lead scientist for the Mayall z-band Legacy Survey (MzLS) carried out at Kitt Peak, and as co-lead scientist with Schlegel for the Dark Energy Camera Legacy Survey (DECaLS) carried out at a NOIRLab site in Chile.

    The third DESI-preparatory survey, known as the Beijing-Arizona Sky Survey or (BASS), was conducted at Kitt Peak and supported by an international collaboration including the Chinese Academy of Sciences and the University of Arizona.

    Researchers from China made more than 90 trips to Kitt Peak to carry out observations for BASS, which was supported by an international collaboration including the National Astronomical Observatories of China (NAOC) and the University of Arizona. “A joint research team of more than 40 people from 11 institutes in China and the U.S. participated in BASS and contributed to the success of this data release,” said Hu Zou, an astrophysicist at the Key Laboratory of Optical Astronomy in Beijing and a co-lead investigator for BASS. “This team will also play an important role in the future of the DESI survey and related sciences,” he added.

    The MzLS survey, meanwhile, featured a rebuilt camera designed to see the infrared light emitted by distant, faint galaxies. Equipped with four large, ultrasensitive light-capturing sensors, called CCDs, the MzLS survey camera produced images of galaxies 10 times fainter than those sampled in a previous survey. DESI itself is outfitted with very similar CCDs that enable it to capture light from objects up to 12 billion light-years away, and both sets of CCDs were developed at Berkeley Lab.

    The collective effort of the three surveys, Dey said, “was one of the most uniform, deep surveys of the sky that has ever been undertaken. It was really exciting to participate.”

    All of the raw data from the imaging surveys has been released to the scientific community and public. This final data release, known as Data Release 9 or DR9, has been preceded by eight other data releases. The data have already spawned several disparate research projects, including citizen science efforts that utilize the wisdom of crowds.

    Dey, along with Schlegel, is a part of a research effort that uses a machine-learning algorithm to automatically identify light-bending phenomena known as gravitational lenses in the DESI surveys data, for example.

    Aaron Meisner, a NOIRLab researcher and DESI participant, is also involved in the lensing study and in a citizen science project called Backyard Worlds: Planet 9, which calls for the general public’s help in finding a possible ninth planet in our solar system by studying space images. Participants have already found numerous new brown dwarfs, which are small, cold stars unable to sustain fusion burn.

    Galaxy Zoo, another citizen science project, opens up DESI’s DECaLS survey data to the public to get help with galaxy classifications.

    “The imaging data provides a deep resource that is essential to carry out DESI’s unique mission while giving the scientific community access to an extraordinary dataset,” said DESI Director Michael Levi, a senior scientist at Berkeley Lab. “We look forward to using these imaging data to yield new clues and reveal the secrets of our expanding universe.”

    NERSC is a DOE Office of Science User Facility.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    LBNL campus

    LBNL Molecular Foundry

    Bringing Science Solutions to the World
    In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

    Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (UC) and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the UC Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

    Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a UC Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.

    A U.S. Department of Energy National Laboratory Operated by the University of California.

    University of California Seal

     
  • richardmitnick 11:12 pm on January 13, 2021 Permalink | Reply
    Tags: "Doubling the Number of Known Gravitational Lenses", , , , , Machine learning key to discovery of over 1200 gravitational lenses., NOIRLab, Only 1 in 10000 massive galaxies are expected to show evidence of strong gravitational lensing ., The data were collected at Cerro Tololo Inter-American Observatory (CTIO) (CL) and Kitt Peak National Observatory (KPNO) both Programs of the National Science Foundation’s NOIRLab., The lensing study was possible because of the availability of science-ready data from the DESI Legacy Imaging Surveys., The researchers turned to a kind of machine learning known as a deep residual neural net.   

    From NOIRLab: “Doubling the Number of Known Gravitational Lenses” 

    NOIRLab composite

    From NOIRLab

    13 January 2021

    Xiaosheng Huang
    University of San Francisco
    Cell: +1 510 316 8390
    Email: xhuang22@usfca.edu

    Arjun Dey
    NSF’s NOIRLab
    Cell: +1 520 981 9024
    Email: dey@noao.edu

    David Schlegel
    Lawrence Berkeley National Laboratory (LBNL)
    Cell: +1 510 965 3287
    Email: djschlegel@lbl.gov

    Amanda Kocz
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    Machine learning key to discovery of over 1200 gravitational lenses.

    1
    Examples of gravitational lenses found in the DESI Legacy Survey data. Credit: KPNO/CTIO/NOIRLab/NSF/AURA/Legacy Imaging Survey.

    2
    An example of a gravitational lens found in the DESI Legacy Surveys data. There are four sets of lensed images in DESI-090.9854-35.9683 [above], corresponding to four distinct background galaxies — from the outermost giant red arc to the innermost bright blue arc, arranged in four concentric circles. All of them are gravitationally warped — or lensed — by the orange galaxy at the very center. Credit: NOIRLab.


    This is CosmoView Episode 19 for press release noirlab2104: Doubling the Number of Known Gravitational Lenses
    Credit: Images and Videos: KPNO/CTIO/NOIRLab/NSF/AURA/Legacy Imaging Survey, D. Munizaga, P. Marenfeld.
    NASA/ESA Hubble Space Telescope/ NASA Chandra X-ray Observatory.
    Music: zero-project – The Lower Dungeons (zero-project.gr).

    Data from the DESI (Dark Energy Spectroscopic Instrument) Legacy Imaging Surveys have revealed over 1200 new gravitational lenses, approximately doubling the number of known lenses. Discovered using machine learning trained on real data, these warped and stretched images of distant galaxies provide astronomers with a flood of new targets with which to measure fundamental properties of the Universe such as the Hubble constant, which describes the expanding Universe.

    Astronomers hunting for gravitational lenses utilized machine learning to inspect the vast dataset known as the DESI Legacy Imaging Surveys, uncovering 1210 new lenses. The data were collected at Cerro Tololo Inter-American Observatory (CTIO) and Kitt Peak National Observatory (KPNO), both Programs of the National Science Foundation’s NOIRLab. The ambitious DESI Legacy Imaging Surveys just had its ninth and final data release.

    Discussed in scientific journals since the 1930s, gravitational lenses are products of Einstein’s General Theory of Relativity. The theory says that a massive object, such as a cluster of galaxies, can warp spacetime. Some scientists, including Einstein, predicted that this warping of spacetime might be observable, as a stretching and distortion of the light from a background galaxy by a foreground cluster of galaxies. The lenses typically appear in images as arcs and streaks around foreground galaxies and galaxy clusters.

    Only 1 in 10,000 massive galaxies are expected to show evidence of strong gravitational lensing [1], and locating them is not easy. Gravitational lenses allow astronomers to explore the most profound questions of our Universe, including the nature of dark matter and the value of the Hubble constant, which defines the expansion of the Universe. A major limitation of the use of gravitational lenses until now has been the small number of them known.

    “A massive galaxy warps the spacetime around it, but usually you don’t notice this effect. Only when a galaxy is hidden directly behind a giant galaxy is a lens possible to see,” notes the lead author of the study, Xiaosheng Huang from the University of San Francisco. “When we started this project in 2018, there were only about 300 confirmed strong lenses.”

    “As a co-leader in the DESI Legacy Surveys I realized this would be the perfect dataset to search for gravitational lenses,” explains study co-author David Schlegel of Lawrence Berkeley National Laboratory (LBNL). “My colleague Huang had just finished teaching an undergraduate class on machine learning at the University of San Francisco, and together we realized this was a perfect opportunity to apply those techniques to a search for gravitational lenses.”

    The lensing study was possible because of the availability of science-ready data from the DESI Legacy Imaging Surveys, which were conducted to identify targets for DESI’s operations, and from which the ninth and final dataset has just been released. 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 Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at CTIO in Chile; the Mayall z-band Legacy Survey (MzLS) [2], by the Mosaic3 camera on the Nicholas U. Mayall 4-meter Telescope at 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.

    “We designed the Legacy Surveys imaging project from the ground up as a public enterprise, so that it could be used by any scientist,” said study co-author Arjun Dey, from NSF’s NOIRLab. “Our survey has already yielded more than a thousand new gravitational lenses, and there are undoubtedly many more awaiting discovery.

    The DESI Legacy Imaging Surveys data are served to the astronomical community via the Astro Data Lab at NOIRLab’s Community Science and Data Center (CSDC). “Providing science-ready datasets for discovery and exploration is core to our mission,” said CSDC Director Adam Bolton. “The DESI Legacy Imaging Surveys is a key resource that can be used for years to come by the astronomy community for investigations like these.”

    To analyze the data, Huang and team used the National Energy Research Scientific Computer Center’s (NERSC) supercomputer at DOE’s Lawrence Berkeley National Laboratory. “The DESI Legacy Imaging Surveys were absolutely crucial to this study; not just the telescopes, instruments, and facilities but also data reduction and source extraction,” explains Huang. “The combination of the breadth and depth of the observations is unparalleled.”

    With the huge amount of science-ready data to work through, the researchers turned to a kind of machine learning known as a deep residual neural net. Neural nets are computing algorithms that are somewhat comparable to a human brain and are used for solving artificial intelligence problems. Deep neural nets have many layers that collectively can decide whether a candidate object belongs to a particular group. In order to be able to do this, however, the neural nets have to be trained to recognize the objects in question [3].

    With the large number of lens candidates now on hand, researchers can make new measurements of cosmological parameters such as the Hubble constant. The key will be to detect a supernova in the background galaxy, which, when lensed by a foreground galaxy, will appear as multiple points of light. Now that astronomers know which galaxies show evidence for strong lensing, they know where to search. New facilities such as the Vera C. Rubin Observatory (currently under construction in Chile and operated by NOIRLab) will monitor objects like these as part of its mission, allowing any supernova to be measured rapidly by other telescopes.

    NOIRLab Vera C. Rubin Observatory Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes, altitude 2,715 m (8,907 ft).

    Undergraduate students played a significant role in the project from its beginning. University of California student Andi Gu said, “My role on the project has helped me develop several skills which I believe to be key for my future academic career.”

    Notes

    [1] Strong gravitational lenses are those where the effect is easily visible in the form of arcs or Einstein Rings.

    [2] z-band means the data were taken in the infrared, centered on a wavelength of 900 nm.

    [3] As an example, imagine trying to train a human who has never seen the night sky how to recognize a star. You would have to describe certain characteristics: it is small, it is bright, it is on a dark background. But immediately there are challenges. What if several stars are close together? What if the sky is a bit cloudy? What if the object is blinking (so is not a star at all, but a plane)? It quickly becomes clear that defining a clear set of rules to describe an object is actually very difficult. However, any human who has seen the night sky will simply be able to recognize other stars once they have seen them. This is the sort of thing that humans are very good at, and computers are very bad at. Hence the necessity to train highly sophisticated neural nets to recognize the desired objects.

    More information

    This research was presented in the paper Discovering New Strong Gravitational Lenses in the DESI Legacy Imaging Surveys to appear in The Astrophysical Journal.

    The team is composed of X. Huang (Department of Physics and Astronomy, University of San Francisco), C. Storfer (Department of Physics and Astronomy, University of San Francisco), A. Gu (Department of Physics, University of California, Berkeley), V. Ravi (Department of Computer Science, University of San Francisco), A. Pilon (Department of Physics and Astronomy, University of San Francisco), W. Sheu (Department of Physics, University of California, Berkeley), R. Venguswamy (Department of Physics, University of California, Berkeley), S. Banka (Department of Physics, University of California, Berkeley), A. Dey (NSF’s NOIRLab), M. Landriau (Physics Division, Lawrence Berkeley National Laboratory), D. Lang (Physics Division, Lawrence Berkeley National Laboratory; Department of Astronomy & Astrophysics, University of Toronto (CA); Perimeter Institute for Theoretical Physics, Waterloo (CA), A. Meisner (NSF’s NOIRLab), J. Moustakas (Department of Physics and Astronomy, Siena College), A. D. Myers (Department of Physics & Astronomy, University of Wyoming), R. Sajith (Department of Physics, University of California, Berkeley), E. F. Schlafly (NSF’s NOIRLab), and D. J. Schlegel (Physics Division, Lawrence Berkeley National Laboratory).

    See the full article here.

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    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 10:29 pm on January 13, 2021 Permalink | Reply
    Tags: "Giant Map of the Sky Sets Stage for Ambitious DESI Survey", , , , , , , , NOIRLab, The DESI collaboration will select 35 million galaxies and 2.4 million quasars in the map — some as far away as 12 billion light-years — as targets for the DESI survey.   

    From NOIRLab: “Giant Map of the Sky Sets Stage for Ambitious DESI Survey” 

    NOIRLab composite

    From NOIRLab

    13 January 2021

    David Schlegel
    Lawrence Berkeley National Laboratory (LBNL)
    Cell: +1 510 965 3287
    Email: djschlegel@lbl.gov

    Arjun Dey
    NSF’s NOIRLab
    Cell: +1 520 981 9024
    Email: dey@noao.edu

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    1
    A group of galaxies nicknamed the Copeland Septet, in the constellation of Leo.
    Astronomers using images from Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory have created the largest ever map of the sky, comprising over a billion galaxies.

    Kitt Peak National Observatory 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.

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

    The ninth and final data release from the ambitious DESI Legacy Imaging Surveys sets the stage for a ground-breaking 5-year survey with the Dark Energy Spectroscopic Instrument (DESI), which aims to provide new insights into the nature of dark energy. The map was released today at the January 2021 meeting of the American Astronomical Society.

    LBNL/DESI spectroscopic instrument on the Mayall 4-meter telescope at Kitt Peak National Observatory started in 2018.

    NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)

    For millennia humans have used maps to understand and navigate our world and put ourselves in context: we rely on maps to show us where we are, where we came from, and where we’re going. Astronomical maps continue this tradition on a vast scale. They locate us within the cosmos and tell the story of the history and fate of the Universe: it will expand forever, the expansion currently accelerating because of an unknown quantity called dark energy. Astronomical maps may help explain what this dark energy is and why it exists.

    Capitalizing on that possibility requires an unprecedented map — one that charts faint galaxies more uniformly and over a larger area of sky than ever before. To meet that challenge, astronomers have now created a new two-dimensional map of the sky that is the largest ever made in terms of sky coverage, sensitivity, and the total number of galaxies mapped.

    From among the more than 1 billion galaxies in the map, astronomers will select tens of millions of galaxies for further study with the Dark Energy Spectroscopic Instrument (DESI), in order to construct the largest 3D map ever attempted. The results from the DESI survey, which will be carried out at Kitt Peak National Observatory (KPNO), a Program of National Science Foundation’s NOIRLab, will ultimately provide new insights into the nature of dark energy.

    The new map is the result of the DESI Legacy Imaging Surveys, an ambitious 6-year effort involving 1405 observing nights at three telescopes, years of data from a space telescope, 150 observers and 50 other researchers from around the world, 1 petabyte of data (1000 trillion bytes), and 100 million CPU hours on one of the world’s most powerful computers. The images were taken at KPNO and Cerro Tololo Inter-American Observatory (CTIO), also a Program of NOIRLab, and supplemented by images from NASA’s Wide-field Infrared Survey Explorer (WISE) mission.

    NASA/WISE NEOWISE Telescope.

    The data were reduced at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC).

    National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory

    NERSC Cray Cori II supercomputer, named after Gerty Cori, the first American woman to win a Nobel Prize in science.

    NERSC Hopper Cray XE6 supercomputer, named after Grace Hopper, One of the first programmers of the Harvard Mark I computer.

    NERSC Cray XC30 Edison supercomputer.

    NERSC GPFS for Life Sciences.


    The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

    NERSC PDSF computer cluster in 2003.

    PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

    Future:

    Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supeercomputer

    NERSC is a DOE Office of Science User Facility.

    Arjun Dey, the DESI Project Scientist for NOIRLab, co-led two of the three imaging surveys, serving as the lead scientist for the Mayall z-band Legacy Survey (MzLS) observed by the Mosaic3 camera on the Nicholas U. Mayall 4-meter Telescope at KPNO, and as co-lead scientist with Schlegel for the Dark Energy Camera Legacy Survey (DECaLS) on DECam on the Víctor M. Blanco 4-meter Telescope at CTIO in Chile.

    Dark Energy Camera [DECam], built at FNAL.

    The third survey is the Beijing-Arizona Sky Survey (BASS) observed 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.

    2.3-metre Bok Telescope at the Steward Observatory at Kitt Peak in the the Quinlan Mountains in the Arizona-Sonoran Desert on the Tohono O’odham Nation, 88 kilometers 55 mi west-southwest of Tucson, Arizona, USA, Altitude 2,096 m (6,877 ft).

    The collective effort of the three surveys, Dey said, “was one of the most uniform, deep surveys of the sky that has ever been undertaken. It was really exciting to participate.”

    The DESI collaboration will select 35 million galaxies and 2.4 million quasars in the map — some as far away as 12 billion light-years — as targets for the DESI survey. Over five years of operations, DESI will create a giant 3D map of the Universe by measuring the galaxies’ distances and the rate at which they are moving away from us. To make these measurements, DESI will take the fingerprint of a galaxy by measuring its spectrum: the light from individual galaxies will be dispersed into fine bands of color.

    Capturing the spectra of so many galaxies so quickly requires a high degree of automation. DESI — equipped with an array of 5000 swiveling, automated robots, each toting a thin fiber-optic cable that can point at individual galaxies — is designed to measure the spectra of 5000 galaxies at a time. The results will ultimately provide new insights into the mysterious dark energy that is driving the Universe’s accelerating expansion.

    The quest to understand the nature of dark energy has led to major opportunities for discovery in other areas of astronomy. Adam Bolton, Director of NOIRLab’s Community Science and Data Center, explained: “To solve some of the biggest mysteries in fundamental physics today, we are driven to create huge digital databases of stars and galaxies, which in turn enable a new data-mining approach to making additional astronomical discoveries.”

    With the completion of the DESI Legacy Imaging Surveys, all data have been released to the scientific community and the public. This final data release, known as Data Release 9, has been preceded by eight other intermediate data releases.

    NOIRLab will host these data products in the Astro Data Archive, from the original images taken at the telescopes to the catalogs that report the positions and other properties of stars and galaxies. Astro Data Lab also serves the catalogs as databases, which astronomers can easily analyze using the Astro Data Lab tools and services, and cross-match them with other datasets, giving more opportunities for discovery. In addition, Astro Data Lab provides astronomers with example scientific applications and tutorials to assist with their research. The DESI Legacy Imaging Surveys data have already been used for many other research projects [1] [2], including citizen science efforts that utilize the wisdom of crowds [3].

    Notes

    [1] One study uses a machine-learning algorithm to automatically identify light-bending phenomena known as gravitational lenses in the DESI surveys data.

    [2] Another study employs spectroscopy from the Sloan Digital Sky Survey together with the Legacy Surveys imaging to reveal the presence of active black holes in galaxies, and giving us a preview of a large population of active galaxies to be discovered with the DESI spectroscopic survey. This work is being led by NOIRLab astronomer Stephanie Juneau.

    [3] The citizen science project Backyard Worlds: Planet 9 enlists the general public’s help in finding a possible ninth planet in our Solar System, by searching for moving objects in the data. Participants have already discovered new cool worlds in the vicinity of the Sun — objects more massive than planets but lighter than stars, known as brown dwarfs. Several of these are among the very coolest brown dwarfs known, with a few approaching the temperature of Earth and cool enough to harbor water clouds. Recently the largest map of brown dwarfs in our neighborhood was published. Backyard Worlds is co-led by Aaron Meisner, a NOIRLab astronomer and DESI participant.

    DESI is supported by the US Department of Energy’s Office of High Energy Physics; the US National Science Foundation, Division of Astronomical Sciences under contract to the NSF’s NOIRLab; the Science and Technologies Facilities Council of the United Kingdom; the Gordon and Betty Moore Foundation; the Heising-Simons Foundation; the French Alternative Energies and Atomic Energy Commission (CEA); the National Council of Science and Technology of Mexico; the Ministry of Economy of Spain; and DESI member institutions. The DESI scientists are honored to be permitted to conduct astronomical research on Iolkam Du’ag (Kitt Peak), a mountain with particular significance to the Tohono O’odham Nation.

    Current DESI Member Institutions include: Aix-Marseille University; Argonne National Laboratory; Barcelona-Madrid Regional Participation Group; Brookhaven National Laboratory; Boston University; Brazil Regional Participation Group; Carnegie Mellon University; CEA-IRFU, Saclay (FR); China Participation Group (CN); Cornell University; Durham University (UK); École Polytechnique Fédérale de Lausanne (CH); Eidgenössische Technische Hochschule, Zürich; Fermi National Accelerator Laboratory; Granada-Madrid-Tenerife Regional Participation Group (ES); Harvard University; Kansas State University; Korea Astronomy and Space Science Institute (KR); Korea Institute for Advanced Study; Lawrence Berkeley National Laboratory; Laboratoire de Physique Nucléaire et de Hautes Énergies (FR); Max Planck Institute (DE); Mexico Regional Participation Group (MX); New York University; NSF’s NOIRLab; Ohio University; Perimeter Institute (CA); Shanghai Jiao Tong University (CN); Siena College; SLAC National Accelerator Laboratory; Southern Methodist University; Swinburne University (UK); The Ohio State University; Universidad de los Andes (CO); University of Arizona; University of Barcelona (ES); University of California, Berkeley; University of California, Irvine; University of California, Santa Cruz; University College London (UK); University of Florida; University of Michigan at Ann Arbor; University of Pennsylvania; University of Pittsburgh; University of Portsmouth (UK); University of Queensland (AU); University of Rochester; University of Toronto (CA); University of Utah; University of Waterloo (CA); University of Wyoming; University of Zurich (CH); UK Regional Participation Group; Yale University.

    For more information, visit desi.lbl.gov.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 10:18 pm on January 12, 2021 Permalink | Reply
    Tags: "NOIRLab Scientist Finds the Universe to be Brighter than Expected", , , , , , , NOIRLab   

    From NOIRLab: “NOIRLab Scientist Finds the Universe to be Brighter than Expected” 

    NOIRLab composite

    From NOIRLab

    12 January 2021

    Tod Lauer
    NSF’s NOIRLab
    Cell: +1 520 861 4618
    lauer@noao.edu

    Amanda Kocz
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    amanda.kocz@noirlab.edu

    1
    Measurements of the Universe’s darkness performed with NASA’s New Horizons probe reveal an unexplained glow to the Universe. These results are presented at the January 2021 meeting of the American Astronomical Society.[1]

    NOIRLab’s facilities focus on ground-based astronomy, but NOIRLab scientists also use data from space telescopes to answer their astronomical questions — and sometimes even use space probes designed to visit other planets. A team of astronomers led by NOIRLab scientist Tod Lauer, which included other members of the New Horizons science team and Marc Postman from the Space Telescope Science Institute (STScI), used the New Horizons spacecraft [2] to answer a fundamental question — how dark is the Universe?

    “The Universe is dark, but not as dark as we thought,” said Lauer.

    This measurement — known as the cosmic optical background — is the visible equivalent of the well-known cosmic microwave background.

    1
    Cosmic Optical Background.
    Researchers analyzed these fields imaged by LORRI [Long Range Reconnaissance Imager on NASA/New Horizons spacecraft]. Image Credit: Tod Lauer et al.

    “While the cosmic microwave background tells us about the first 450,000 years after the Big Bang, the cosmic optical background tells us something about the sum total of all the stars that have ever formed since then,” explained Postman. “It puts a constraint on the total number of galaxies that have been created, and where they might be in time.”

    The key to the team’s approach was to use a telescopic camera on the New Horizons space probe as it was traveling through the outer regions of the Solar System, rather than the Hubble Space Telescope or any other probe operating around Earth or the inner Solar System. Having flown past Pluto in 2015 and the remote Kuiper Belt object Arrokoth in 2019, New Horizons is now more than 7 billion kilometers (4 billion miles) from Earth. This distance gives the space probe a much darker sky to measure, providing astronomers with more accurate results. Just as light pollution limits the view of the night sky in cities, sunlight scattered by tiny dust particles in the inner Solar System completely overwhelms the faint background light coming from the distant Universe.[3]

    In the far outer regions of the Solar System, New Horizons was able to measure the intrinsic darkness of the night sky and estimate the number of galaxies populating the Universe.

    After correcting their measurement by subtracting a number of light sources, such as the known stars in the Milky Way and reflections from interstellar dust, the team found that some light remained. The source of this extra light remains unclear. One possibility is that a large number of dwarf galaxies in the nearby Universe lie just beyond detectability. Equally possible is that the diffuse halos of stars that surround galaxies might be brighter than expected. Other possibilities include a population of rogue, intergalactic stars spread throughout the cosmos — or there simply may be many more faint, distant galaxies than theories suggest.

    In addition, the study shows that there are far fewer unseen galaxies — galaxies that are too faint to be directly observed — in the Universe than previous estimates suggested. The measurements of this weak background glow show that the unseen galaxies are less plentiful than some theoretical studies suggested. Galaxies appear to number only in the hundreds of billions rather than the two trillion previously extrapolated from observations by the Hubble Space Telescope.
    Notes

    [1] This result will be featured in an online session at the 237th American Astronomical Society meeting: “New Horizons Detection of the Cosmic Optical Background” on Wednesday, 13 January at 12:40pm EST.

    [2] New Horizons is a NASA space probe designed to explore the outer Solar System, particularly Pluto. Launched in 2006, it completed its Pluto flyby in 2015 and is now on an extended voyage through the Kuiper Belt. Amongst its various scientific instruments, New Horizons is equipped with a small 20-centimeter (8-inch) telescope — which proved to be key for this research (LORRI [Long Range Reconnaissance Imager]).

    [3] This ambient glow is known as zodiacal light and is often seen from Earth by astrophotographers, stargazers, and other dark sky enthusiasts.

    Science paper:
    New Horizons Observations of the Cosmic Optical Background
    Accepted for publication in The Astrophysical Journal.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 10:45 pm on January 5, 2021 Permalink | Reply
    Tags: "Deep Dive into a Galaxy Cluster", , , , , NOIRLab   

    From NOIRLab: “Deep Dive into a Galaxy Cluster” 

    NOIRLab composite

    From NOIRLab

    5 January 2021

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    amanda.kocz@noirlab.edu

    Stunning deep image of NGC 1003 reveals hundreds of cluster galaxies.

    1
    A stunning long-exposure observation from the Kitt Peak National Observatory reveals the spiral galaxy NGC 1003 in glorious detail. The deep observation also shows a treasure trove of background galaxies spread throughout the image.

    Astronomers refer to observations as “deep” when they are taken with very long exposure times. Just as with photography, this gathers more light, revealing distant, fainter objects. Deeper exposures let astronomers look deeper into the Universe — hence the name. This particular deep image was taken with a 70-minute exposure with the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, and captures the spiral galaxy NGC 1003.

    NOAO/Mayall 4 m telescope at Kitt Peak, Arizona, USA, Altitude 2,120 m (6,960 ft)

    Kitt Peak National Observatory 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.

    NGC 1003 lies over 30 million light-years from Earth in the direction of the constellation Perseus. While it makes for a spectacular sight, it is only one of many galaxies captured in this image. Upon closer inspection, other galaxies can also be seen strewn throughout the image, with everything from delicate spiral galaxies to hundreds of fuzzy, red elliptical galaxies lurking in the background.

    3
    A stunning long-exposure observation lasting 70 minutes from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, reveals the surroundings of the spiral galaxy NGC 1003 in glorious detail. NGC 1003 resides in front of a galaxy cluster — a vast collection of galaxies bound together by gravity. The long exposure time of this deep observation allowed these usually overlooked red background cluster galaxies to be captured. Credit: KPNO/NOIRLab/NSF/AURA.

    The long exposure time of this deep observation — arguably the deepest image of NGC 1003 ever captured — allowed these usually overlooked background cluster galaxies to be captured in breathtaking detail.

    Deep images such as this one have had an important role in shaping our understanding of the Universe. In 1995, the Hubble Space Telescope famously observed a tiny, nondescript patch of sky for 10 days to create the Hubble Deep Field.

    NASA/ESA Hubble Deep Field.

    Hubble Ultra Deep Field. NASA/ESA Hubble.

    The observations revealed thousands of distinct galaxies, showing that our Universe is a surprisingly crowded place.

    While the Hubble team deliberately avoided bright galaxies for their observation, this ground-based observation is littered with galaxies of all shapes and sizes — a spectacular backdrop for this portrait of NGC 1003. As well as revealing the host of background galaxies, the long exposure time of this observation allowed the researchers to capture the faint outer reaches of NGC 1003, which are threaded through with bright tendrils of stars. Equally eye-catching is the bright heart of the galaxy, which is surrounded by clouds of dense dust.

    NGC 1003 resides in front of a galaxy cluster — a vast collection of galaxies bound together by gravity. These structures are among the most massive in the known Universe, and outweigh the Sun by a factor of a thousand trillion. Just as stars can be grouped into clusters, and these star clusters into galaxies, galaxies themselves form clusters and even superclusters — building up the large-scale structure of our Universe.

    Laniakea supercluster. From Nature The Laniakea supercluster of galaxies R. Brent Tully, Hélène Courtois, Yehuda Hoffman & Daniel Pomarède at http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html. Milky Way is the red dot.

    BOSS Supercluster Baryon Oscillation Spectroscopic Survey (BOSS)


    CosmoView Episode 16: Deep Dive into a Galaxy Cluster.


    Zooming on NGC 1003

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 2:26 pm on December 1, 2020 Permalink | Reply
    Tags: "Dark Energy Camera Snaps Deepest Photo yet of Galactic Siblings", , , , , NOIRLab   

    From NOIRLab: “Dark Energy Camera Snaps Deepest Photo yet of Galactic Siblings” 

    NOIRLab composite

    From NOIRLab

    1 December 2020

    David Nidever
    Assistant Professor, Department of Physics, Montana State University
    Bozeman, MT 59717
    Cell: +1 434-249-6845
    Email: david.nidever@montana.edu

    Knut Olsen
    NSF’s NOIRLab
    Cell: +1 520-664-4465
    Email: amanda.kocz@noirlab.edu

    Amanda Kocz
    Press and Internal Communications Officer
    NSF’s NOIRLab
    Cell: +1 626 524 5884
    Email: amanda.kocz@noirlab.edu

    A treasure trove of data from the SMASH survey unveils the Magellanic Clouds in exquisite detail.

    1
    Images from the Survey of the MAgellanic Stellar History (SMASH) reveal a striking family portrait of our galactic neighbors — the Large and Small Magellanic Clouds. The images represent a portion of the second data release from the deepest, most extensive survey of the Magellanic Clouds. The observations consist of roughly 4 billion measurements of 360 million objects.

    2
    Part of the SMASH dataset showing what is arguably the best wide-angle view of the Small Magellanic Cloud to date. The Large and Small Magellanic Clouds are the largest satellite galaxies of the Milky Way and, unlike the rest of the satellite galaxies, are still actively forming stars — and at a rapid pace. Credit: CTIO/NOIRLab/NSF/AURA/SMASH/D. Nidever (Montana State University)
    Acknowledgment: Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Marti.


    CosmoView Episode 15: Dark Energy Camera Snaps Deepest Photo yet of Galactic Siblings.

    A sprawling portrait of two astronomical galactic neighbors presents a new perspective on the swirls of stars, gas, and dust making up the nearby dwarf galaxies known as the Large and Small Magellanic Clouds — a pair of dwarf satellite galaxies to our Milky Way [1]. While this isn’t the first survey to map these nearby cosmic siblings — the Survey of the MAgellanic Stellar History (SMASH) is the most extensive survey yet.

    The international team of astronomers responsible for the observations used the 520-megapixel high-performance Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. These data are now available to astronomers worldwide through Astro Data Lab at NOIRLab’s Community Science and Data Center (CSDC). CTIO and CSDC are both Programs of NSF’s NOIRLab.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    “To date, this is the deepest and most extensive astronomical dataset of the Magellanic Clouds, which are the closest large galaxies to us,” explains David Nidever, Assistant Professor in the Physics Department at Montana State University and Principal Investigator of the SMASH survey. “These satellite galaxies have been studied for decades, but SMASH is being used to map out their structure over their full, enormous extent and help solve the mystery of their formation.”

    The complete SMASH survey, which includes the view shown in these images, covers an area 2,400 times greater than the full Moon, and required about 50 nights of specialized observations. This second data release contains new data from DECam on the central and most complex regions of the Magellanic Clouds. The Large and Small Magellanic Clouds are the largest satellite galaxies of the Milky Way and, unlike the rest of the satellite galaxies, are still actively forming stars — and at a rapid pace.

    Though large numbers of dwarf galaxies such as the Magellanic Clouds populate the Universe, the vast majority are too faint and distant for astronomers to study. Having the Large and Small Magellanic Clouds as neighbors provides astronomers with a unique opportunity to investigate the formation and evolution of small galaxies — but also poses a challenge.

    As the Magellanic Clouds are so close to the Milky Way, they sprawl across a large area of the sky, making it challenging to map their full extent. DECam’s huge field of view allowed astronomers to capture details within some of the most interesting regions of these dwarf galaxies.

    The SMASH team are using their deep dataset to study the history of star formation across both of these galaxies. They have uncovered evidence that the pair of galaxies have collided with each other in the recent past and that this sparked the recent episode of intense star formation.

    “These are beautiful multicolor images of the Milky Way’s nearest neighboring galaxies. Through the care the dedicated team has taken, they give us a remarkable view of the thirteen billion year history of star formation in these galaxies,” notes National Science Foundation program officer Glen Langston.

    One of the team’s long-term goals is to use the information they have obtained about the history of star formation to create a “movie” of how these galaxies evolved over time. Other topics that the SMASH team hope astronomers will explore include searching for star clusters with the help of citizen scientists and measuring the metal content of stars in the Magellanic Clouds.

    “These latest SMASH data of the central regions of the Magellanic Clouds, where most of the stars are found, are unique in their combined depth, breadth, and uniformity,” Knut Olsen, NOIRLab scientist and survey co-leader explains. “Besides producing amazing images, these data allow us to look into the past and reconstruct how the Magellanic Clouds formed their stars over time; with these ‘movies’ of star formation we can try to understand how and why these galaxies evolved.”

    This second dataset from the SMASH survey will be made available to the astronomical community jointly through Astro Data Lab, which serves the tables of measurements, and the Astro Data Archive, which serves the images, allowing researchers from all over the world to delve into the history of the Magellanic Clouds.

    Adam Bolton, Director of CSDC, explains, “As a modern astronomy research lab, NOIRLab provides both the observing platform for teams of scientists to conduct ambitious surveys like SMASH, and the data-science platform for the entire astronomical community to exploit the resulting data products for new discoveries.”

    “We’re just getting started,” comments David Nidever. “Data from the SMASH survey have the potential to revolutionize our understanding of the stars making up the Magellanic Clouds.’”

    Notes

    [1] Though the masses of these dwarf galaxies are enormous — the Large Magellanic Cloud alone has a mass 10 billion times greater than the Sun’s — they are galactic small fry compared to the Milky Way, which is roughly ten times more massive than the Large Magellanic Cloud.

    Large Magellanic Cloud. Adrian Pingstone December 2003

    More information

    This research will be presented in the paper The Second Data Release of the Survey of the MAgellanic Stellar History, in The Astronomical Journal.

    The SMASH team is composed of David Nidever (Montana State University and NSF’s NOIRLab), Knut Olsen (NSF’s NOIRLab), Yumi Choi (Space Telescope Science Institute, Montana State University and University of Arizona), Tomas Ruiz-Lara (University of Groningen, Instituto de Astrofísica de Canarias and Universidad de La Laguna), Amy Miller (University of Potsdam and Leibniz-Institut für Astrophysik Potsdam (AIP) and Montana State University), L. Clifton Johnson (Northwestern University), Cameron P. M. Bell (AIP), Robert D. Blum (Vera C. Rubin Observatory), Maria-Rosa Cioni (AIP), Carme Gallart (Instituto de Astrofísica de Canarias and Universidad de La Laguna), Steven R. Majewski (University of Virginia), Nicolas F Martin (University of Strasbourg and Max Planck Institute for Astronomy), Pol Massana (University of Surrey), Antonela Monachesi (University of La Serena), Noelia E. D. Noël (University of Surrey), Joanna D. Sakowska (University of Surrey), Roeland P. van der Marel (Space Telescope Science Institute and Johns Hopkins University), Alistair R. Walker (NSF’s NOIRLab/CTIO), Dennis Zaritsky (University of Arizona), Eric F. Bell (University of Michigan), Blair C. Conn (Mount Stromlo Observatory and IAG Ltd), Thomas J. L. de Boer (University of Hawai‘i), Robert A. Gruendl (National Center for Supercomputing Applications and University of Illinois), Matteo Monelli (Instituto de Astrofísica de Canarias and Universidad de La Laguna), Ricardo R. Muñoz (University of Illinois), Abhijit Saha (NSF’s NOIRLab), A. Katherina Vivas (NSF’s NOIRLab/CTIO), Edouard Bernard (CNRS), Gurtina Besla (University of Arizona), Julio A. Carballo-Bello (Tarapacá University), Antonio Dorta (Instituto de Astrofísica de Canarias and Universidad de La Laguna), David Martinez-Delgado (Instituto de Astrofísica de Andalucía), Alex Goater (University of Surrey), Vadim Rusakov (Cosmic Dawn Center and University of Copenhagen), and Guy S. Stringfellow (University of Colorado).

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    What is NSF’s NOIRLab?

    NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF 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 11:26 am on August 17, 2020 Permalink | Reply
    Tags: "Surprisingly Dense Exoplanet Challenges Planet Formation Theories", , , , , NOIRLab, , The exoplanet K2-25b   

    From NOIRLab: “Surprisingly Dense Exoplanet Challenges Planet Formation Theories” 

    NOIRLab composite

    From NOIRLab

    1
    New detailed observations with NSF’s NOIRLab facilities reveal a young exoplanet, orbiting a young star in the Hyades cluster, that is unusually dense for its size and age. Slightly smaller than Neptune, K2-25b orbits an M-dwarf star — the most common type of star in the galaxy — in 3.5 days.
    Credit: NOIRLab/NSF/AURA/J. Pollard.

    New observations of the exoplanet, known as K2-25b, made with the WIYN 0.9-meter Telescope at Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab, the Hobby-Eberly Telescope at McDonald Observatory and other facilities, raise new questions about current theories of planet formation [1]. The exoplanet has been found to be unusually dense for its size and age — raising the question of how it came to exist. Details of the findings appear in The Astronomical Journal.

    NOAO WIYN .9 meter Telescope at Kitt Peak National Observatory 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)

    U Texas McDonald Observatory Hobby-Eberly 9.1 meter Telescope, Altitude 2,070 m (6,790 ft)

    Slightly smaller than Neptune, K2-25b orbits an M-dwarf star — the most common type of star in the galaxy — in 3.5 days. The planetary system is a member of the Hyades star cluster, a nearby cluster of young stars in the direction of the constellation Taurus. The system is approximately 600 million years old, and is located about 150 light-years from Earth.

    Planets with sizes between those of Earth and Neptune are common companions to stars in the Milky Way, despite the fact that no such planets are found in our Solar System. Understanding how these “sub-Neptune” planets form and evolve is a frontier question in studies of exoplanets.

    Astronomers predict that giant planets form by first assembling a modest rock-ice core of 5–10 times the mass of Earth and then enrobing themselves in a massive gaseous envelope hundreds of times the mass of Earth. The result is a gas giant like Jupiter. K2-25b breaks all the rules of this conventional picture: with a mass 25 times that of Earth and modest in size, K2-25b is nearly all core and very little gaseous envelope. These strange properties pose two puzzles for astronomers. First, how did K2-25b assemble such a large core, many times the 5–10 Earth-mass limit predicted by theory? [2] And second, with its high core mass — and consequent strong gravitational pull — how did it avoid accumulating a significant gaseous envelope?

    The team studying K2-25b found the result surprising. “K2-25b is unusual,” said Gudmundur Stefansson, a postdoctoral fellow at Princeton University, who led the research team. According to Stefansson, the exoplanet is smaller in size than Neptune but about 1.5 times more massive. “The planet is dense for its size and age, in contrast to other young, sub-Neptune-sized planets that orbit close to their host star,” said Stefansson. “Usually these worlds are observed to have low densities — and some even have extended evaporating atmospheres. K2-25b, with the measurements in hand, seems to have a dense core, either rocky or water-rich, with a thin envelope.”

    To explore the nature and origin of K2-25b, astronomers determined its mass and density. Although the exoplanet’s size was initially measured with NASA’s Kepler satellite, the size measurement was refined using high-precision measurements from the WIYN 0.9-meter Telescope at KPNO and the 3.5-meter telescope at Apache Point Observatory (APO) in New Mexico.

    The observations made with these two telescopes took advantage of a simple but effective technique that was developed as part of Stefansson’s doctoral thesis. The technique uses a clever optical component called an Engineered Diffuser, which can be obtained off the shelf for around $500. It spreads out the light from the star to cover more pixels on the camera, allowing the brightness of the star during the planet’s transit to be more accurately measured, and resulting in a higher-precision measurement of the size of the orbiting planet, among other parameters [3].

    “The innovative diffuser allowed us to better define the shape of the transit and thereby further constrain the size, density and composition of the planet,” said Jayadev Rajagopal, an astronomer at NOIRLab who was also involved in the study.

    For its low cost, the diffuser delivers an outsized scientific return. “Smaller aperture telescopes, when equipped with state-of-the-art, but inexpensive, equipment can be platforms for high impact science programs,” explains Rajagopal. “Very accurate photometry will be in demand for exploring host stars and planets in tandem with space missions and larger apertures from the ground, and this is an illustration of the role that a modest-sized 0.9-meter telescope can play in that effort.”

    Thanks to the observations with the diffusers available on the WIYN 0.9-meter and APO 3.5-meter telescopes, astronomers are now able to predict with greater precision when K2-25b will transit its host star. Whereas before transits could only be predicted with a timing precision of 30–40 minutes, they are now known with a precision of 20 seconds. The improvement is critical to planning follow-up observations with facilities such as the international Gemini Observatory and the James Webb Space Telescope[4].

    Many of the authors of this study are also involved in another exoplanet-hunting project at KPNO: the NEID spectrometer on the WIYN 3.5-meter Telescope. NEID enables astronomers to measure the motion of nearby stars with extreme precision — roughly three times better than the previous generation of state-of-the-art instruments — allowing them to detect, determine the mass of, and characterize exoplanets as small as Earth.
    Notes

    [1] The planet was originally detected by Kepler in 2016. Detailed observations for this study were made using the Habitable-zone Planet Finder on the 11-meter Hobby-Eberly Telescope at McDonald Observatory.

    [2] The prediction from theory is that once planets have formed a core of 5–10 Earth-masses they begin to accrete gas instead: very little rocky material is added after that.

    [3] Diffusers were first used for exoplanet observations in 2017.

    [4] GHOST, on Gemini South, will be used to carry out transit spectroscopy of exoplanets found by Kepler and TESS. Their target list includes the star K2-25.
    More information

    The team is composed of Gudmundur Stefansson (The Pennsylvania State University and Princeton University), Suvrath Mahadevan (The Pennsylvania State University), Marissa Maney (The Pennsylvania State University), Joe P. Ninan (The Pennsylvania State University), Paul Robertson (University of California, Irvine), Jayadev Rajagopal (NSF’s NOIRLab), Flynn Haase (NSF’s NOIRLab), Lori Allen (NSF’s NOIRLab), Eric B. Ford (The Pennsylvania State University), Joshua Winn (Princeton), Angie Wolfgang (The Pennsylvania State University), Rebekah I. Dawson (The Pennsylvania State University), John Wisniewski (University of Oklahoma), Chad F. Bender (University of Arizona), Caleb Cañas (The Pennsylvania State University), William Cochran (The University of Texas at Austin), Scott A. Diddams (National Institute of Standards and Technology, and University of Colorado), Connor Fredrick (National Institute of Standards and Technology, and University of Colorado), Samuel Halverson (Jet Propulsion Laboratory), Fred Hearty (The Pennsylvania State University), Leslie Hebb (Hobart and William Smith Colleges), Shubham Kanodia (The Pennsylvania State University), Eric Levi (The Pennsylvania State University), Andrew J. Metcalf (Air Force Research Laboratory, National Institute of Standards and Technology, and University of Colorado), Andrew Monson (The Pennsylvania State University), Lawrence Ramsey (The Pennsylvania State University), Arpita Roy (California Institute of Technology), Christian Schwab (Macquarie University), Ryan Terrien (Carleton College), and Jason T. Wright (The Pennsylvania State University).

    See the full article here.

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    Please help promote STEM in your local schools.

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    What is NSF’s NOIRLab?

    As of 1 October 2019, all National Science Foundation-funded ground-based nighttime optical and infrared astronomical research facilities operate together in one organization called NSF’s National Optical-Infrared Astronomy Research Laboratory (NSF’s NOIRLab). The new organization operates five scientific facilities: Cerro Tololo Inter-American Observatory (CTIO); the Community Science and Data Center (CSDC); Gemini Observatory; Kitt Peak National Observatory (KPNO); and the Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF.

    NOIRLab is the preeminent US center for ground-based optical-infrared astronomy, enabling breakthrough discoveries in astrophysics by developing and operating state-of-the-art ground-based observatories and providing data products and services for a diverse and inclusive community.

    NOIRLab serves as a focal point for community development of innovative scientific programs, the exchange of ideas, and domestic and international collaborations.

     
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