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  • richardmitnick 7:27 pm on April 21, 2021 Permalink | Reply
    Tags: , , , , The University of Texas at Austin   

    From insideHPC : “Continuing Arecibo’s Legacy – A Partnership to Save Telescope Data at TACC” 

    From insideHPC

    April 21, 2021
    Jorge Salazar, Science Writer, TACC

    Millions of people have seen footage of the famed Arecibo radio telescope’s collapse – due to various hurricanes and other natural disasters – in December 2020. What they would not have seen from those videos was Arecibo’s data center, located outside the danger zone. It stores the “golden copy” of the telescope’s data — the original tapes, hard drives, and disk drives of sky scans since the 1960s.

    Now, a new partnership will make sure that about 3 petabytes, or 3,000 terabytes, of telescope data is securely backed up off-site and made accessible to astronomers around the world, who will be able to use it to continue Arecibo Observatory’s legacy of discovery and innovation.

    Working Together

    [It must not be forgotten that the NSF was de-funding Arecibo, a severe loss to the US Radio Astronomy community.]

    Within weeks of Arecibo’s collapse, the Texas Advanced Computing Center (TACC)(US) entered into an agreement with the University of Central Florida (US), the Engagement and Performance Operations Center (US) (EPOC), the Arecibo Observatory, the Cyberinfrastructure Center of Excellence Pilot (CICoE Pilot) (US), and Globus Research data management simplified (US) at the University of Chicago (US). Together, they’re moving the Arecibo radio telescope data to TACC’s Ranch, a long-term data mass storage system. Plans include expanding access to over 50 years of astronomy data from the Arecibo Observatory, which up until 2016 had been the world’s largest radio telescope.

    “I’m thrilled that University of Texas at Austin (US) will become the home of the data repository for one of the most important telescopes of the past half-century,” said Dan Jaffe, Interim Executive Vice President and Provost of The University of Texas at Austin.

    “As a young radio astronomer, I saw Arecibo as an amazing symbol of the commitment of our country to the science I loved,” Jaffe said. “Arecibo made important contributions across many fields — studies of planets, setting the scale for the expansion of the universe, understanding the clouds from which stars form, to name a few. Preserving these data and making them available for further study will allow Arecibo’s legacy to have an ongoing impact on my field.”

    “Arecibo data has led to hundreds of discoveries over the last 50 years,” said Francisco Cordova, Director of the Arecibo Observatory. “Preserving it, and most importantly, making it available to researchers and students worldwide will undoubtedly help continue the legacy of the facility for decades to come. With advanced machine learning and artificial intelligence tools available now, and in the future, the data provides opportunity for even more discoveries and understanding of recently discovered physical phenomena.”

    National Science Foundation (US) Vision

    Since 2018, University of Central Florida (US) has led the consortium that manages the Arecibo Observatory, which is owned and funded by the National Science Foundation (NSF). EPOC, a collaboration between Indiana University (US) and the DOE Energy Science Network [ESnet] (US) funded by the U.S. Department of Energy’s Office of Science (SC)(US) and managed by DOE’s Lawrence Berkeley National Laboratory (US), had itself partnered with UCF in profiling their scientific data movement activities a year prior to the collapse.


    TACC’s Ranch supercomputer, a long-term data mass storage system.

    “NSF is committed to supporting Arecibo Observatory as a vital scientific, educational, and cultural center, and part of that will be making sure that the vast amounts of data collected by the telescope continue to drive discovery,” says NSF Program Officer Alison B. Peck. “We’re gratified to see that this partnership will not only safely store copies of Arecibo Observatory’s data but also provide enhanced levels of access for current and future generations of astronomers.”

    The data storage is part of the ongoing efforts at Arecibo Observatory to clean up debris from the 305-meter telescope’s 900-ton instrument platform and reopen remaining infrastructure. NSF is supporting a June 2021 workshop that will focus on actionable ways to support Arecibo Observatory’s future and create opportunities for scientific, educational, and cultural activities.

    Sense of Urgency

    “The collapse of the Arecibo Observatory platform certainly raised a sense of urgency within our team,” said Julio Alvarado, Big Data Program Manager at Arecibo. The Big Data team was already working on a strategic plan for their Data Management and Cloud programs. Those plans had to be prioritized and executed with unprecedented urgency and importance. The legacy of the observatory relied on the data stored for the over 1,700 projects dating back to the 1960’s.

    Alvarado’s team reached out to UCF’s Office of Research for help, which connected Arecibo to two NSF-funded cyberinfrastructure projects, EPOC led by Principal Investigators Jennifer Schopf and Dave Jent from Indiana University, and Jason Zurawski from ESnet; and the Cyberinfrastructure Center of Excellence Pilot (CICoE Pilot) led by Ewa Deelman of the University of Southern California (US).

    “We got involved when the University of Central Florida noted they were having challenges in trying to identify a new data storage location off of the island, and were struggling with the demands of efficiently moving that data,” said Jason Zurawski, Science Engagement Engineer of ESnet and Co-PI of the EPOC project.

    Data Migration

    “Migrating the entire Arecibo data set, well over a petabyte in size, would take many months or even years if done inefficiently, but could take only weeks with proper hardware, software, and configurations,” said Hans Addleman, the Principal Network Systems Engineer for EPOC. The EPOC team provided the infrastructure skills and resources that helped Arecibo design their data transfer framework using the latest research tools and expertise. The CICoE Pilot team is helping Arecibo evaluate their data storage solutions and design their future data management and stewardship experience in order to make Arecibo’s data easily accessible to the scientific community.

    Arecibo is an amazing project that has enabled astronomers, planetary scientists, and atmospheric scientists to collect and analyze extremely valuable scientific data over many decades,” said Ewa Deelman, Research Director at the USC Information Sciences Institute, and PI of the CI CoE Pilot project.

    “The CI CoE Pilot project is very excited to be working with Arecibo, EPOC, TACC, and Globus members in this community effort, making sure the precious data is preserved and made easily findable, accessible, interoperable, and reusable (FAIR). Recently, we have also reached out to members of the International Virtual Observatory Alliance (IVOA), and in particular Bruce Berriman (Caltech/IPACNASA Exoplanet Science Institute (US), Vice-Chair of the IVOA Executive Committee) to explore Arecibo’s data role in the international community. The collaboration formed around and with Arecibo shows how NSF-funded projects can come together, amplify each other’s efforts and have an impact on the international scientific community,” Deelman added.

    CI CoE Pilot contributes expertise in a number of areas spanning the Arecibo data lifecycle, including data archiving (Angela Murillo, Indiana University), identity management (Josh Drake, IU), semantic technologies (Chuck Vardeman, University of Notre Dame (US)), visualization (Valerio Pascucci and Steve Petruzza, University of Utah (US)), and workflow management (Mats Rynge, and Karan Vahi, USC). The CI CoE Pilot effort is coordinated by Wendy Whitcup (USC).

    As a result of Arecibo’s limited Internet connectivity, the University of Puerto Rico and Engine-4, a non-profit coworking space and laboratory, are contributing to the data transfer process by allowing Arecibo to share their Internet infrastructure. Further, the irreplaceable nature of the data required a solution that would guarantee data integrity while maximizing transfer speed. This motivated the use of Globus, a platform for research data management developed and operated by the University of Chicago.

    The Transfer

    The data transfer process started mid-January 2021. Arecibo’s data landscape consists of three main sources: data in hard drives; data in tape library; and data offsite. The archive holds over one petabyte of data in hard drives and over two petabytes of data in tapes. This data includes information from thousands of observing sessions, equivalent to watching 120 years of HD video.

    Currently, data is being transferred from Arecibo hard drives to TACC’s Ranch system, recently upgraded to expand its storage capabilities to an exabyte, or 1,000 petabytes. Ranch upgrades combine a DDN SFA14K DCR block storage system with a Quantum Scalar i6000 tape library.

    Over 52,000 users archive their data from all facets of science, from the subatomic to the cosmic. Ranch is an allocated resource of the XSEDE-Extreme Science Engineering Discovery Environment (US) funded by the National Science Foundation (NSF).

    “Further phases will copy the Arecibo tape library to hard drives and then to TACC, and a later phase will copy data from offsite locations to TACC,” Alvarado said.

    To preserve and guarantee continuity to the scientific community, Arecibo’s data is being copied to storage devices, which are then delivered to the University of Puerto Rico at Mayaguez and to the Engine-4 facilities for upload. This ensures that the research community continues to access and execute research with the existing data. This data migration is executed in coordination with Arecibo’s IT department, led by Arun Venkataraman.

    Given time constraints and limitations in the networking infrastructure connecting the observatory, speed, security, and reliability were key to effectively moving the data.

    The Globus service addressed these needs, while also providing a means to monitor the transfers and automatically recover from any transient errors. This was necessary to minimize the chance of losing or corrupting the valuable data collected by the telescope in its 50+ years of service.

    The Globus service enabled the UCF and ESNet teams to securely and reliably move 12 TBs (spell out) of data per day. “Seeing the impact that our services can have on preserving the legacy of a storied observatory such as Arecibo is truly gratifying”, said Rachana Ananthakrishnan, Globus executive director at the University of Chicago.

    The data travel over the AMPATH Internet exchange point that connects the University of Puerto Rico to Miami. It then uses Internet2 and the LEARN network in Texas to get to TACC in Austin.

    Arecibo’s Data Legacy

    The data were collected from Arecibo’s 1,000 foot (305 meter) fixed spherical radio/radar telescope. Its frequency capabilities range from 50 megahertz to 11 gigahertz. Transmitters include an S-band (2,380 megahertz) radar system for planetary studies; a 430 megahertz radar system for atmospheric science studies; and a heating facility for ionospheric research.

    Past achievements made with Arecibo include the discovery of the first ever binary pulsar, a find that tested Einstein’s General Theory of Relativity and earned its discoverers a Nobel Prize in 1993; the first radar maps of the Venusian surface and polar ice on Mercury; and the first planet found outside our solar system.

    “The data is priceless,” Alvarado emphasized. Arecibo’s data includes a variety of astronomical, atmospheric, and planetary observations dating to the 1960s that can’t be duplicated.

    “While some of the data led to major discoveries over the years, there are reams of data that have yet to be analyzed and could very likely yield more discoveries. Arecibo’s plan is to work with TACC to provide researchers access to the data and the tools necessary to easily retrieve data to continue the science mission at Arecibo,” he said.

    The Arecibo IT and Big Data teams are in charge of the data during the migration phases of the project, which doesn’t allow public access. As the migration and data management efforts progresses, the data will be made available to the research community.

    Arecibo, TACC, EPOC, CICoE Pilot, and Globus will continue to work on building tools, processes, and framework to support the continuous access and analysis of the data to the research community. The data will be stored at TACC temporarily, supporting Arecibo’s goal of providing open access to the data. Arecibo will continue to work with the groups on the design and development of a permanent storage solution.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Founded on December 28, 2006, insideHPC is a blog that distills news and events in the world of HPC and presents them in bite-sized nuggets of helpfulness as a resource for supercomputing professionals. As one reader said, we’re sifting through all the news so you don’t have to!

    If you would like to contact me with suggestions, comments, corrections, errors or new company announcements, please send me an email at rich@insidehpc.com. Or you can send me mail at:

    insideHPC
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  • richardmitnick 10:51 pm on December 3, 2020 Permalink | Reply
    Tags: "Chaotic Early Solar System Collisions Resembled ‘Asteroids’ Arcade Game", , , , , , The University of Texas at Austin   

    From University of Texas at Austin: “Chaotic Early Solar System Collisions Resembled ‘Asteroids’ Arcade Game” 

    U Texas Austin bloc

    From University of Texas at Austin

    Dec 02, 2020

    1
    A cross-polarized image of the Artracoona meteorite under 50 times magnification. Credit: Michael Lucas.

    2
    An elemental X-ray map of a portion of the Peekskill meteorite. Different colors correspond to different elements. Credit: Michael Lucas.

    One Friday evening in 1992, a meteorite ended a more than 150 million-mile journey by smashing into the trunk of a red Chevrolet Malibu in Peekskill, New York. The car’s owner reported that the 30-pound remnant of the earliest days of our solar system was still warm and smelled of sulfur.

    Nearly 30 years later, a new analysis of that same Peekskill meteorite and 17 others by researchers at The University of Texas at Austin and the University of Tennessee, Knoxville, has led to a new hypothesis about how asteroids formed during the early years of the solar system.

    The meteorites studied in the research originated from asteroids and serve as natural samples of the space rocks. They indicate that the asteroids formed though violent bombardment and subsequent reassembly, a finding that runs counter to the prevailing idea that the young solar system was a peaceful place.

    The study was published in print Dec.1 in the journal Geochimica et Cosmochimica Acta.

    The research began when co-author Nick Dygert was a postdoctoral fellow at UT’s Jackson School of Geosciences studying terrestrial rocks using a method that could measure the cooling rates of rocks from very high temperatures, up to 1,400 degrees Celsius.

    Dygert, now an assistant professor at the University of Tennessee, realized that this method — called a rare earth element (REE)-in-two-pyroxene thermometer — could work for space rocks, too.

    “This is a really powerful new technique for using geochemistry to understand geophysical processes, and no one had used it to measure meteorites yet,” Dygert said.

    Since the 1970s, scientists have been measuring minerals in meteorites to figure out how they formed. The work suggested that meteorites cooled very slowly from the outside inward in layers. This “onion shell model” is consistent with a relatively peaceful young solar system where chunks of rock orbited unhindered. But those studies were only capable of measuring cooling rates from temperatures near about 500 degrees Celsius.

    When Dygert and Michael Lucas, a postdoctoral scholar at the University of Tennessee who led the work, applied the REE-in-two-pyroxene method, with its much higher sensitivity to peak temperature, they found unexpected results. From around 900 degrees Celsius down to 500 degrees Celsius, cooling rates were 1,000 to 1 million times faster than at lower temperatures.

    How could these two very different cooling rates be reconciled?

    The scientists proposed that asteroids formed in stages. If the early solar system was, much like the old Atari game “Asteroids,” rife with bombardment, large rocks would have been smashed to bits. Those smaller pieces would have cooled quickly. Afterward, when the small pieces reassembled into larger asteroids we see today, cooling rates would have slowed.

    To test this rubble pile hypothesis, Jackson School Professor Marc Hesse and first-year doctoral student Jialong Ren built a computational model of a two-stage thermal history of rubble pile asteroids for the first time.

    Because of the vast number of pieces in a rubble pile —1015 or a thousand trillions — and the vast array of their sizes, Ren had to develop new techniques to account for changes in mass and temperature before and after bombardment.

    “This was an intellectually significant contribution,” Hesse said.

    The resulting model supports the rubble pile hypothesis and provides other insights as well. One implication is that cooling slowed so much after reassembly not because the rock gave off heat in layers. Rather, it was that the rubble pile contained pores.

    “The porosity reduces how fast you can conduct heat,” Hesse said. “You actually cool slower than you would have if you hadn’t fragmented because all of the rubble makes kind of a nice blanket. And that’s sort of unintuitive.”

    Tim Swindle of the Lunar and Planetary Laboratory at the University of Arizona, who studies meteorites but was not involved in the research, said that this work is a major step forward.

    “This seems like a more complete model, and they’ve added data to part of the question that people haven’t been talking about, but should have been. The jury is still out, but this is a strong argument.”

    The research was supported by NASA. The Smithsonian National Museum of Natural History supplied samples of meteorites for the study.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Texas Austin campus

    U Texas at Austin
    In 1839, the Congress of the Republic of Texas ordered that a site be set aside to meet the state’s higher education needs. After a series of delays over the next several decades, the state legislature reinvigorated the project in 1876, calling for the establishment of a “university of the first class.” Austin was selected as the site for the new university in 1881, and construction began on the original Main Building in November 1882. Less than one year later, on Sept. 15, 1883, The University of Texas at Austin opened with one building, eight professors, one proctor, and 221 students — and a mission to change the world. Today, UT Austin is a world-renowned higher education, research, and public service institution serving more than 51,000 students annually through 18 top-ranked colleges and schools.

     
  • richardmitnick 6:21 pm on December 1, 2020 Permalink | Reply
    Tags: "Hobby-Eberly Telescope Dark Energy Experiment survey begins full operations", , , , , , , The University of Texas at Austin   

    From Pennsylvania State University and University of Texas at Austin: “Hobby-Eberly Telescope Dark Energy Experiment survey begins full operations” 

    Penn State Bloc

    From Pennsylvania State University

    and

    U Texas Austin bloc

    From University of Texas at Austin

    December 01, 2020
    Rebecca Johnson and Sam Sholtis

    Media Contacts
    Donald Schneider
    dps@astro.psu.edu
    Work Phone: 814-863-9554

    Robin Ciardullo
    rbc3@psu.edu
    Work Phone: (814) 404-8626

    Caryl Gronwall
    caryl.gronwall@psu.edu
    Work Phone: (814) 404-1950

    Donghui Jeong
    djeong@psu.edu
    Work Phone: (512) 879-7806

    Sam Sholtis
    sjs144@psu.edu
    Work Phone: 814-865-1390

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

    U Texas at Austin McDonald Observatory, Altitude 2,070 m (6,790 ft).

    Three years after its initial test observations, the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is now training its full suite of instrumentation to reveal the nature and evolution of dark energy, the mysterious entity that is the primary constituent of the universe.

    HETDEX, which is a large international consortium led by the University of Texas at Austin and involves approximately 100 scientists including Penn State researchers, plans to construct one of the largest maps of the cosmos ever made. The three-dimensional map of 2.5 million galaxies will help astronomers to better understand why the expansion of the universe is currently accelerating.

    “Penn State is delighted to be a participant in this fundamental scientific investigation,” said Donald Schneider, a member of the Hobby-Eberly Telescope (HET) Board of Directors and distinguished professor and head of Penn State’s Department of Astronomy and Astrophysics. “The telescope’s innovative design was by two Penn State astronomers, Lawrence Ramsey and Daniel Weedman, and a number of Penn State astronomers are playing important roles in the observations and data analysis in HETDEX.”

    2
    The two black structures to the left and right of the Hobby-Eberly Telescope’s main mirror are nicknamed ‘saddlebags.’ They hold the dozens of spectrographs that make up the VIRUS instrument designed to undertake HETDEX, the Hobby-Eberly Telescope Dark Energy Experiment. Credit: Ethan Tweedie Photography.

    HETDEX is using the 10-meter HET, located at McDonald Observatory in western Texas, to obtain data from two large regions of the sky; one field is in the direction of the Big Dipper, the other is slightly southwest of the constellation of Orion. Each time the telescope is pointed at these regions, which typically last 20 minutes, HETDEX’s instrumentation records approximately 32,000 spectra, capturing the cosmic fingerprint of the light from every object within the 10-meter telescope’s field of view.

    “HETDEX has arrived,” said University of Texas astronomer Karl Gebhardt, who is the survey’s project scientist. “We’re over a third of the way through our program now, and we have this fantastic dataset that we’re going to use to measure the dark energy evolution.”

    HETDEX is a “blind” survey; rather than pointing at specific targets, it records light from all sources over a specific patch of sky. These spectra are recorded via 32,000 optical fibers that feed into more than 100 instruments working together as a single spectrograph. This assembly, the Visible Integral-field Replicable Unit Spectrograph (VIRUS), is a complex system consisting of dozens of copies of an instrument working together for efficiency. VIRUS was designed and built especially for HETDEX.

    Building VIRUS “was quite a task to orchestrate,” said Gary Hill, a University of Texas astronomer and the designer of the instrument. “It’s the largest on many measures,” he said, noting that it has the most optical fibers, as well as having as much detector area as the largest astronomical cameras. VIRUS is also an extremely imposing instrument, claiming much of the volume inside the telescope dome.

    3
    This image shows the ‘focal surface’ of the Hobby-Eberly Telescope, where the optical fibers of VIRUS are arrayed. The circles each contain a square grid of 448 fibers. When the telescope is pointed and VIRUS takes an observation, each of the 32,000 fibers takes a spectrum simultaneously, recording a vast array of information on the speed, direction, and chemical makeup of every point inside the field of view, which is about the size of the full Moon.
    Credit: J. Pautzke/E. Mrozinski/G. Hill/HETDEX Collaboration.

    The HETDEX team expects to complete their observations by December 2023. In total, the completed survey will include one billion spectra, “the largest ever spectral survey by far,” Gebhardt said.

    “To investigate the properties of dark matter and its evolution, we must identify a few million galaxies of a specific type in the roughly one billion HETDEX spectra and create a map of their three-dimensional distribution,” explained Donghui Jeong, associate professor of astronomy and astrophysics at Penn State and leader of the HETDEX science group investigating large scale structures in the universe. “By examining the locations of these galaxies, we can compare the observations to models of dark energy and determine the influence of ordinary matter, dark matter, and dark energy at various points in the history of the universe.”

    Other Penn State HETDEX participants include Professor of Astronomy and Astrophysics Robin Ciardullo, who is the observations manager for HETDEX; Research Professor Caryl Gronwall; and Associate Professor Derek Fox.

    “The galaxies that will be studied in HETDEX are from the universe’s distant past,” said Gronwall. “The light we detect left these objects approximately ten billion years ago, when the universe was but a few billion years of age.”

    4
    This false-color image of the Pinwheel Galaxy (Messier 101) shows the power of the VIRUS instrument built for the HETDEX survey. The image is a mosaic made up of the central portion of 21 VIRUS pointings across a region of sky about half the size of the full Moon, with some small gaps in coverage. The colors show the contrast between young stars (blue/white) and older stars (red/orange). The breakout boxes show just four examples of the ‘cosmic fingerprint’ of objects in this view. Clockwise from top left: a white dwarf in our galaxy, an active galaxy 11 billion light-years away, a star-forming region in the Pinwheel Galaxy 20 million light-years away, and a star-forming galaxy 3 billion light-years away.
    Credit: G. Zeimann/HETDEX Collaboration.

    Taft Armandroff, director of The University of Texas at Austin’s McDonald Observatory and Chair of the HET Board of Directors, noted, “HETDEX represents the coming together of many astronomers and institutions to conduct the first major study of how dark energy changes over time.”

    HETDEX is led by The University of Texas at Austin McDonald Observatory and Department of Astronomy with participation from Penn State; Ludwig Maximilians University, Munich (DE); the Max Planck Institute for Extraterrestrial Physics (DE); the Institute for Astrophysics, Gottingen (DE); the Leibniz Institute for Astrophysics, Potsdam (DE); Texas A&M University; The University of Oxford (UK); the Max Planck Institute for Astrophysics (DE); The University of Tokyo (JP); and the Missouri University of Science and Technology.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Texas at Austin

    U Texas Austin campus

    In 1839, the Congress of the Republic of Texas ordered that a site be set aside to meet the state’s higher education needs. After a series of delays over the next several decades, the state legislature reinvigorated the project in 1876, calling for the establishment of a “university of the first class.” Austin was selected as the site for the new university in 1881, and construction began on the original Main Building in November 1882. Less than one year later, on Sept. 15, 1883, University of Texas at Austin opened with one building, eight professors, one proctor, and 221 students — and a mission to change the world. Today, UT Austin is a world-renowned higher education, research, and public service institution serving more than 51,000 students annually through 18 top-ranked colleges and schools.

    Penn State Campus

    About Penn State

    WHAT WE DO BEST

    We teach students that the real measure of success is what you do to improve the lives of others, and they learn to be hard-working leaders with a global perspective. We conduct research to improve lives. We add millions to the economy through projects in our state and beyond. We help communities by sharing our faculty expertise and research.

    Penn State lives close by no matter where you are. Our campuses are located from one side of Pennsylvania to the other. Through Penn State World Campus, students can take courses and work toward degrees online from anywhere on the globe that has Internet service.

    We support students in many ways, including advising and counseling services for school and life; diversity and inclusion services; social media sites; safety services; and emergency assistance.

    Our network of more than a half-million alumni is accessible to students when they want advice and to learn about job networking and mentor opportunities as well as what to expect in the future. Through our alumni, Penn State lives all over the world.

    The best part of Penn State is our people. Our students, faculty, staff, alumni, and friends in communities near our campuses and across the globe are dedicated to education and fostering a diverse and inclusive environment.

     
  • richardmitnick 10:48 am on November 17, 2020 Permalink | Reply
    Tags: "Texas Astronomers Revive Idea for ‘Ultimately Large Telescope’ on the Moon", , , , , The University of Texas at Austin   

    From University of Texas at Austin: “Texas Astronomers Revive Idea for ‘Ultimately Large Telescope’ on the Moon” 

    U Texas Austin bloc

    From University of Texas at Austin

    16 November 2020

    1

    UT Austin astronomers Anna Schauer, Niv Drory, and Volker Bromm are advocating the revival of the lunar liquid mirror telescope project orginally proposed in 2008 by Roger Angel and collaborators. The Texas group advocates that rather than have a 20-meter liquid mirror (shown), the size be increased to 100 meters so that the telescope can study the first stars that formed in the universe, the so-called Population III stars. They have dubbed this facility the “Ultimately Large Telescope.” Credit: Roger Angel et al./Univ. of Arizona.

    Media Contact
    Rebecca Johnson
    ph: 512-475-6763
    fax: 512-471-5060
    rjohnson@astro.as.utexas.edu

    Science Contact:
    Dr. Anna Schauer, NASA Hubble Fellow
    Department of Astronomy
    The University of Texas at Austin
    http://minihalos.com

    A group of astronomers from The University of Texas at Austin has found that a telescope idea shelved by NASA a decade ago can solve a problem that no other telescope can: It would be able to study the first stars in the universe. The team, led by NASA Hubble Fellow Anna Schauer, will publish their results in an upcoming issue of The Astrophysical Journal.

    “Throughout the history of astronomy, telescopes have become more powerful, allowing us to probe sources from successively earlier cosmic times — ever closer to the Big Bang,” said professor and team member Volker Bromm, a theorist who has studied the first stars for decades. “The upcoming James Webb Space Telescope [JWST] will reach the time when galaxies first formed.

    NASA James Webb Space Telescope annotated.

    “But theory predicts that there was an even earlier time, when galaxies did not yet exist, but where individual stars first formed — the elusive Population III stars. This moment of ‘very first light’ is beyond the capabilities even of the powerful JWST, and instead needs an ‘ultimate’ telescope.”

    These first stars formed about 13 billion years ago. They are unique, born out of a mix of hydrogen and helium gasses, and likely tens or 100 times larger than the Sun. New calculations by Schauer show that a previously proposed facility, a liquid mirror telescope that would operate from the surface of the Moon, could study these stars. Proposed in 2008 by a team led by Roger Angel of The University of Arizona, this facility was called the Lunar Liquid-Mirror Telescope (LLMT).

    NASA had done an analysis on this proposed facility a decade ago, but decided not to pursue the project. According to Niv Drory, a senior research scientist with UT Austin’s McDonald Observatory, the supporting science on the earliest stars did not exist at that point. “This telescope is perfect for that problem,” he said.

    The proposed lunar liquid-mirror telescope, which Schauer has nicknamed the “Ultimately Large Telescope,” would have a mirror 100 meters in diameter. It would operate autonomously from the lunar surface, receiving power from a solar power collection station on the Moon, and relaying data to satellite in lunar orbit.

    Rather than coated glass, the telescope’s mirror would be made of liquid, as it’s lighter, and thus cheaper, to transport to the Moon. The telescope’s mirror would be a spinning vat of liquid, topped by a metallic — and thus reflective —liquid. (Previous liquid mirror telescopes have used mercury.) The vat would spin continuously, to keep the surface of the liquid in the correct paraboloid shape to work as a mirror.

    The telescope would be stationary, situated inside a crater at the Moon’s north or south pole. To study the first stars, it would stare at the same patch of sky continuously, to collect as much light from them as possible.

    “We live in a universe of stars,” Bromm said. “It is a key question how star formation got going early in cosmic history. The emergence of the first stars marks a crucial transition in the history of the universe, when the primordial conditions set by the Big Bang gave way to an ever-increasing cosmic complexity, eventually bringing life to planets, life, and intelligent beings like us.

    “This moment of first light lies beyond the capabilities of current or near-future telescopes. It is therefore important to think about the ‘ultimate’ telescope, one that is capable of directly observing those elusive first stars at the edge of time.”

    The team is proposing that the astronomical community revisit the shelved plan for a lunar liquid-mirror telescope, as a way to study these first stars in the universe.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Texas at Austin

    U Texas Austin campus

    In 1839, the Congress of the Republic of Texas ordered that a site be set aside to meet the state’s higher education needs. After a series of delays over the next several decades, the state legislature reinvigorated the project in 1876, calling for the establishment of a “university of the first class.” Austin was selected as the site for the new university in 1881, and construction began on the original Main Building in November 1882. Less than one year later, on Sept. 15, 1883,

     
  • richardmitnick 4:50 pm on February 10, 2020 Permalink | Reply
    Tags: "Distant Giant Planets Form Differently Than ‘Failed Stars’", , , , , , , NIRC2 camera at Keck observatory in Hawaii., The University of Texas at Austin   

    From Keck Observatory: “Distant Giant Planets Form Differently Than ‘Failed Stars’” 

    Keck Observatory, operated by Caltech and the University of California, Maunakea Hawaii USA, 4,207 m (13,802 ft)

    From Keck Observatory

    February 10, 2020

    A team of astronomers led by Brendan Bowler of The University of Texas at Austin has probed the formation process of giant exoplanets and brown dwarfs, a class of objects that are more massive than giant planets, but not massive enough to ignite nuclear fusion in their cores to shine like true stars.

    1
    This image of the low-mass brown dwarf GJ 504 b was taken by Bowler and his team using adaptive optics with the NIRC2 camera [below] at Keck observatory in Hawaii. the image has been processed to remove light from the host star (whose position is marked with an “x”). the companion is located at a separation of about 40 times the earth-sun distance and has an orbital period of about 240 years. By returning to this and other systems year after year, the team is able to slowly trace out part of the companion’s orbit to constrain its shape, which provides clues about its formation and history.
    Credit: Brendan Bowler (UT-Austin)/W. M. Keck Observatory

    Using direct imaging with ground-based telescopes in Hawaii – W. M. Keck Observatory and NAOJ Subaru Telescope on Maunakea – the team studied the orbits of these faint companions orbiting stars in 27 systems. These data, combined with modeling of the orbits, allowed them to determine that the brown dwarfs in these systems formed like stars, but the gas giants formed like planets.


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

    The research is published in the current issue of The Astronomical Journal.

    In the last two decades, technological leaps have allowed telescopes to separate the light from a parent star and a much-dimmer orbiting object. In 1995, this new capability produced the first direct images of a brown dwarf orbiting a star. The first direct image of planets orbiting another star followed in 2008.

    “Over the past 20 years, we’ve been leaping down and down in mass,” Bowler said of the direct imaging capability, noting that the current limit is about 1 Jupiter mass. As the technology has improved, “One of the big questions that has emerged is ‘What’s the nature of the companions we’re finding?’”

    2
    By patiently watching giant planets and brown dwarfs orbit their host stars, Bowler and his team were able to constrain the orbit shapes even though only a small portion of the orbit has been monitored. The longer the time baseline, the smaller the range of possible orbits. These plots show nine of the 27 systems from their study. Credit: Brendan Bowler (UT-Austin)

    Brown dwarfs, as defined by astronomers, have masses between 13 and 75 Jupiter masses. They have characteristics in common with both planets and with stars, and Bowler and his team wanted to settle the question: Are gas giant planets on the outer fringes of planetary systems the tip of the planetary iceberg, or the low-mass end of brown dwarfs? Past research has shown that brown dwarfs orbiting stars likely formed like low-mass stars, but it’s been less clear what is the lowest mass companion this formation mechanism can produce.

    “One way to get at this is to study the dynamics of the system — to look at the orbits,” Bowler said. Their orbits today hold the key to unlocking their evolution.

    Using Keck Observatory’s adaptive optics (AO) system with the Near-Infrared Camera, second generation (NIRC2) instrument on the Keck II telescope, as well as the Subaru Telescope, Bowler’s team took images of giant planets and brown dwarfs as they orbit their parent stars.

    Keck NIRC2 schematic

    Keck 2 telescope Maunakea Hawaii USA, 4,207 m (13,802 ft)

    It’s a long process. The gas giants and brown dwarfs they studied are so distant from their parent stars that one orbit may take hundreds of years. To determine even a small percentage of the orbit, “You take an image, you wait a year,” for the faint companion to travel a bit, Bowler said. Then “you take another image, you wait another year.”

    This research relied on AO technology, which allows astronomers to correct for distortions caused by the Earth’s atmosphere.

    UCO Keck Laser Guide Star Adaptive Optics,Keck Observatory, operated by Caltech and the University of California, Maunakea Hawaii USA, 4,207 m (13,802 ft)

    Keck Observatory Laser Guide Star Adaptive Optics schematic

    As AO instruments have continually improved over the past three decades, more brown dwarfs and giant planets have been directly imaged. But since most of these discoveries have been made over the past decade or two, the team only has images corresponding to a few percent of each object’s total orbit. They combined their new observations of 27 systems with all of the previous observations published by other astronomers or available in telescope archives.

    At this point, computer modeling comes in. Coauthors on this paper have helped create an orbit-fitting code called “Orbitize!” which uses Kepler’s laws of planetary motion to identify which types of orbits are consistent with the measured positions, and which are not.

    The code generates a set of possible orbits for each companion. The slight motion of each giant planet or brown dwarf forms a “cloud” of possible orbits. The smaller the cloud, the more astronomers are closing in on the companion’s true orbit. And more data points — that is, more direct images of each object as it orbits — will refine the shape of the orbit.

    4
    These two curves show the final distribution of orbit shapes for giant planets and brown dwarfs. The orbital eccentricity determines how elongated the ellipse is, with a value of 0.0 corresponding to a circular orbit and a high value near 1.0 being a flattened ellipse. Gas giant planets located at wide separations from their host stars have low eccentricities, but the brown dwarfs have a wide range of eccentricities similar to binary star systems. For reference, the giant planets in our solar system have eccentricities less than 0.1. Credit: Brendan Bowler (UT-Austin)

    “Rather than wait decades or centuries for a planet to complete one orbit, we can make up for the shorter time baseline of our data with very accurate position measurements,” said team member Eric Nielsen of Stanford University. “A part of Orbitize! that we developed specifically to fit partial orbits, OFTI [Orbits For The Impatient], allowed us to find orbits even for the longest period companions.”

    Finding the shape of the orbit is key: Objects that have more circular orbits probably formed like planets. That is, when a cloud of gas and dust collapsed to form a star, the distant companion (and any other planets) formed out of a flattened disk of gas and dust rotating around that star.

    On the other hand, the ones that have more elongated orbits probably formed like stars. In this scenario, a clump of gas and dust was collapsing to form a star, but it fractured into two clumps. Each clump then collapsed, one forming a star, and the other a brown dwarf orbiting around that star. This is essentially a binary star system, albeit containing one real star and one “failed star.”

    “Even though these companions are millions of years old, the memory of how they formed is still encoded in their present-day eccentricity,” Nielsen added. Eccentricity is a measure of how circular or elongated an object’s orbit is.

    The results of the team’s study of 27 distant companions was unambiguous.

    “The punchline is, we found that when you divide these objects at this canonical boundary of more than about 15 Jupiter masses, the things that we’ve been calling planets do indeed have more circular orbits, as a population, compared to the rest,” Bowler said. “And the rest look like binary stars.”

    The future of this work involves both continuing to monitor these 27 objects, as well as identifying new ones to widen the study. “The sample size is still modest, at the moment,” Bowler said. His team is using the Gaia satellite to look for additional candidates to follow up using direct imaging with even greater sensitivity at the forthcoming Giant Magellan Telescope (GMT) and other facilities. UT-Austin is a founding member of the GMT collaboration.

    ESA/GAIA satellite

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

    Bowler’s team’s results reinforce similar conclusions recently reached by the GPIES direct imaging survey with the Gemini Planet Imager, which found evidence for a different formation channel for brown dwarfs and giant planets based on their statistical properties.

    NOAO Gemini Planet Imager on Gemini South

    Gemini/South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile, at an altitude of 7200 feet

    This work was supported by a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. The Keck Observatory is managed by Caltech and the University of California.

    ABOUT NIRC2

    The Near-Infrared Camera, second generation (NIRC2) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    ABOUT ADAPTIVE OPTICS

    W. M. Keck Observatory is a distinguished leader in the field of adaptive optics (AO), a breakthrough technology that removes the distortions caused by the turbulence in the Earth’s atmosphere. Keck Observatory pioneered the astronomical use of both natural guide star (NGS) and laser guide star adaptive optics (LGS AO) and current systems now deliver images three to four times sharper than the Hubble Space Telescope at near-infrared wavelengths. AO has imaged the four massive planets orbiting the star HR8799, measured the mass of the giant black hole at the center of our Milky Way Galaxy, discovered new supernovae in distant galaxies, and identified the specific stars that were their progenitors. Support for this technology was generously provided by the Bob and Renee Parsons Foundation, Change Happens Foundation, Gordon and Betty Moore Foundation, Mt. Cuba Astronomical Foundation, NASA, NSF, and W. M. Keck Foundation.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatoryoperates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.


    Keck UCal

     
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