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  • richardmitnick 3:59 pm on April 5, 2021 Permalink | Reply
    Tags: "Astronomer publishes survey of young stars", , , Atacama Large Millimeter/submillimeter Array telescope (CL), , , , , , University of Virginia   

    From University of Virginia via phys.org: “Astronomer publishes survey of young stars” 

    From University of Virginia

    via


    From phys.org

    April 5, 2021
    Lorenzo Perez, University of Virginia

    1
    An aerial view of the Chajnantor Plateau, located at an altitude of 5,000 meters in the Chilean Andes, where the array of ALMA antennas is located. Credit: Clem & Adri Bacri-Normier (wingsforscience.com)/European Southern Observatory(EU)

    An international research group led by a postdoctoral fellow in the University of Virginia’s Department of Astronomy identified a rich organic chemistry in young disks surrounding 50 newly formed stars.

    Relying on observations from the Atacama Large Millimeter/submillimeter Array telescope (CL)—known as ALMA—the findings offer astronomers a greater understanding of the mechanisms responsible for the formation of organic molecules in space, at the dawn of planet formation.

    The variety of organic molecules identified also raises an important question for astronomers: How common is the chemical heritage of these disks? Since disks around young stars are known to be the sites of future planet formation, understanding their prebiotic potential is key. The findings of the Star and Planet Formation Laboratory of Japan’s RIKEN Cluster for Pioneering Research [開拓研究本部 ](JP) were published March 23 by the American Astronomical Society (US) in The Astrophysical Journal.

    “This research is going to help us test our current knowledge about the chemical evolution ongoing in the disks of newly formed stars,” said Yao-Lun Yang, lead author of the paper and an Origins postdoctoral fellow with the Virginia Initiative on Cosmic Origins, based in UVA’s Department of Astronomy. Yang was a Japan Society for the Promotion of Science fellow at RIKEN, a national science research institute in Japan when he began work on the project with other researchers affiliated with RIKEN, the University of Tokyo {東京大学;Tōkyō daigaku](JP), IPAG | Grenoble Institute of Planetology and Astrophysics [Institut de Planétologie et d’Astrophysique de Grenoble] (FR), and other institutions.

    “We surveyed the chemical composition of the material where these protoplanetary disks and planets grow from, and what we found quite interesting were the range of complex molecules we observed,” Yang said. “Even where we observed a wide range of total amounts of specific organic molecules, we still found a similar chemical pattern among the different regions we studied.”

    2
    A collection of gas and dust over 500 light-years across, the Perseus Molecular Cloud hosts an abundance of young stars. Credit: National Aeronautics and Space Administration(US)/Jet Propulsion Laboratory-California Institute of Technology(US).

    Studying the Perseus Molecular Cloud

    Stars form from interstellar clouds, which consist of gas and dust, via gravitational contraction. These young stars are surrounded by disks, which have the potential to evolve into planetary systems. Identifying the initial chemical composition of these forming disks may offer clues to the origins of planets like Earth, Yang said.

    The RIKEN-based research focused on 50 sources embedded in the Perseus molecular cloud, which contains young protostars with protoplanetary disks forming around them. Even with the power of the ALMA telescope, it took more than three years, over the course of several projects, to complete the survey. By observing the emission emitted by molecules at specific frequencies, the team studied the amount of methanol, acetonitrile, methyl formate, dimethyl ether, and larger organics—an unprecedented survey of “complex” organic molecules within a large sample of solar-type young stars.

    According to the survey, 58% of the sources contained large organic molecules, while 42% of the sources exhibited no sign of them. Surprisingly, the total amount of any given molecule measured showed a wide variety, more than 100 times difference, even for such similar stars. Some sources proved to be rich in organic molecules, even if they had relatively little material surrounding the protostar. Others featured few organic properties, despite a large amount of material surrounding the protostar. Nonetheless, the relative quantities were remarkably similar.

    The fact that some systems have substantially more or less total organic content suggests that the evolutionary history of the local environment may have a critical impact to the molecular composition in the resultant planetary systems. While the chemical patterns between systems appear to be relatively similar, some disks may “luck out” with more organic richness compared to others.

    Such questions hopefully will be answered in the future through efforts to follow the organic reservoir over time by expanding surveys to even younger or much older systems, Yang said.

    See the full article here.

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Virginia is a public research university in Charlottesville, Virginia. It was founded in 1819 by Thomas Jefferson, one of the Founding Fathers of the United States. It is the flagship university of Virginia and home to the Academical Village, a UNESCO World Heritage Site. UVA is known for its historic foundations, student-run honor code and secret societies.

    The original governing Board of Visitors included Jefferson, James Madison, and James Monroe. Monroe was the sitting President of the United States at the time of its foundation, and earlier Presidents Jefferson and Madison were UVA’s first two rectors. Jefferson conceived and designed the original courses of study and original architecture. UVA was the first university of the American South elected to the research-driven Association of American Universities (US) in 1904. More than a century later, the journal Science credited UVA faculty with two of the top ten global scientific breakthroughs in a single year (2015).

    The University of Virginia offers 121 majors across the eight undergraduate and three professional schools. Its alumni have founded many companies, such as Reddit and CNET, which together produce more than $1.6 trillion in annual revenue and have created 2.3 million jobs. It sits on a historic 1,135-acre (1.8 sq mi; 459.3 ha) central campus partially protected by UNESCO. The university additionally maintains 562 acres north of the campus at North Fork, and 2,913 acres southeast of the city at Morven Farm. Moreover, it manages the College at Wise in Southwest Virginia and until 1972 managed George Mason University and the University of Mary Washington (US) in Northern Virginia.

    Virginia student athletes are called Cavaliers and lead the Atlantic Coast Conference in men’s team NCAA Championships with 20, ranking third in women’s and second in overall NCAA titles. Virginia men’s basketball and Virginia men’s lacrosse won NCAA Championships in 2019 to join several Cavalier teams in winning recent national championship events including the College Cup, College World Series, and NCAA Tennis Championships. The collective men’s programs won the Capital One Cup in 2015 and 2019 after leading the nation in overall athletics excellence across all sports. Virginia is one of three universities to win the Cup multiple times.

    Research

    The University of Virginia is the first and longest serving member of the Association of American Universities (US) in the American South, attaining membership in 1904. It is classified among “R1: Doctoral Universities – Very high research activity”.

    According to the National Science Foundation (US), UVa spent $614 million on research and development in 2019, ranking it 44th in the nation and 1st in Virginia. Built in 1996, North Fork (formerly the UVA Research Park) is an extensive 3.7-million square foot, 562 acre research park nine miles north of UVA’s North Grounds. It houses the UVA Applied Research Institute as well as many private R&D efforts by such firms as Battelle, The MITRE Corporation, Signature Science, and CACI.

    UVA is also home to globally recognized research on hypersonic flight for National Aeronautics and Space Administration(US) and others. The United States Air Force, National Science Foundation, and National Center for Hypersonic Combined Cycle Propulsion have each also granted UVA researchers millions in funding for the university’s ongoing broad and deep research into ultra-high velocity flight. Starting in 2015, a UVA team led by mechanical engineering professor Eric Loth began Department of Energy (US) funded research into an original design of offshore wind turbines that would potentially dwarf the size and scope of any being produced or researched anywhere else. The innovative design inspired by palm trees led to Loth being named to a Popular Science list of “The Brilliant Minds Behind The New Energy Revolution”.

    UVA was recognized by Science as leading two of the top 10 scientific discoveries in the world in 2015. The first breakthrough was when UVA School of Medicine researchers Jonathan Kipnis and Antoine Louveau discovered previously unknown vessels connecting the human brain directly to the lymphatic system. The discovery “redrew the map” of the lymphatic system, rewrote medical textbooks, and struck down long-held beliefs about how the immune system functions in the brain. The discovery may help greatly in combating neurological diseases from multiple sclerosis to Alzheimer’s disease. The second globally recognized breakthrough of 2015 was when UVA psychology professor Brian Nosek examined the reproducibility of 100 psychology studies and found fewer than half could be reproduced. The discovery may have profound impacts on how psychological studies are performed and documented. More than 270 researchers on five continents were involved, and twenty-two students and faculty from UVA were listed as co-authors on the scientific paper.

    In the field of astrophysics, the university is a member of a consortium engaged in the construction and operation of the Large Binocular Telescope in the U Arizona Mount Graham International Observatory (US) of the Pinaleno Mountains of southeastern Arizona. It is also a member of both the Astrophysical Research Consortium (US), which operates telescopes at Apache Point Observatory (US) in New Mexico, and the Association of Universities for Research in Astronomy (US) which operates the National Optical Astronomy Observatory (US), the NOIRLab NOAO Gemini Observatory (US) and the National Aeronautics and Space Administration(US) Space Telescope Science Institute (US). The University of Virginia hosts the headquarters of the National Radio Astronomy Observatory (US), which operates the Green Bank Telescope (US) in West Virginia and the National Science Foundation(US) National Radio Astronomy Observatory(US) Very Large Array radio telescope made famous in the Carl Sagan television documentary Cosmos and film Contact. The North American Atacama Large Millimeter Array Science Center is also at the Charlottesville NRAO site. In 2019, researchers at NRAO co-authored a study documenting the discovery of a pair of giant hourglass shaped balloons emanating radio waves from the center of our Milky Way galaxy.

     
  • richardmitnick 12:06 pm on February 5, 2021 Permalink | Reply
    Tags: "A Warp in the Milky Way Linked to Galactic Collision", APOGEE-an infrared spectrograph developed by UVA at SDSS, , , , , , Rather than being symmetrical the disc structure is warped-more like the brim of a fedora., The warped edges are constantly moving around the outer rim of the galaxy., University of Virginia   

    From University of Virginia: “A Warp in the Milky Way Linked to Galactic Collision” 

    UVA bloc

    From University of Virginia

    February 04, 2021
    Russ Bahorsky
    rsb5x@virginia.edu

    1
    A graphical representation of the Milky Way showing its warped outer edges. Credit: Xinlun Cheng.

    Milky Way NASA/JPL-Caltech /ESO R. Hurt. The bar is visible in this image.

    When most of us picture the shape of the Milky Way, the galaxy that contains our own sun and hundreds of billions of other stars, we think of a central mass surrounded by a flat disc of stars that spiral around it. However, astronomers know that rather than being symmetrical, the disc structure is warped, more like the brim of a fedora, and that the warped edges are constantly moving around the outer rim of the galaxy.

    “If you have ever seen the audience making a wave in a stadium, it’s very similar to that concept,” said Xinlun Cheng, an astronomy graduate student in the University of Virginia’s College and Graduate School of Arts & Sciences. “Each member of the audience stands up and then sits down at the correct time and in the correct order to create the wave as it goes around the stadium. That’s exactly what stars in our galaxy are doing. Only in this case, as the wave is going around the galaxy’s disk, the galaxy disk is also rotating around the center of the galaxy. In terms of the sports-fan analogy, it’s as if the stadium itself is also rotating.”

    What caused that warp to occur has been the subject of debate. Some researchers suggest that the phenomenon is a result of the instability of the galaxy itself, while others assert that it is the remnant of a collision with another galaxy in the distant past.

    A recent article published in The Astrophysical Journal by Cheng, who studies the movements of the stars, and his colleagues, Borja Anguiano, a post-doctoral research associate at UVA, and Steven Majewski, a professor in the College’s Department of Astronomy, may finally put that debate to rest.

    Using data from the Gaia space observatory, a satellite launched in 2013 by the European Space Agency to measure the positions, distances and motions of billions of stars and information from APOGEE, an infrared spectrograph developed by UVA to examine the chemical composition and motions of stars, astronomers now have the tools to observe the movements of the stars in the Milky Way with an unprecedented degree of accuracy.

    ESA (EU)/GAIA satellite .

    SDSS APOGEE spectrograph, from UVA.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft).

    Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft).

    “By combining information from the APOGEE instrument with information from the Gaia satellite, we’re starting to understand how the different components of the galaxy are moving,” said Anguiano, who is interested both in the movements of those components and what phenomena may have originally caused those movements to occur.

    “It is now possible to characterize those movements with unprecedented accuracy because of the precision and statistical robustness of the huge catalogue of stars that has been probed by the Gaia satellite,” Majewski explained. “Meanwhile, our own large database of stellar chemistries generated by APOGEE gives us the unique ability to infer stellar ages. This allows us to explore how stars of different age participate in the warp and lets us zero in on when it was created. Knowing this, then, gives us an idea of why it was created.”

    Using those data, Cheng and his colleagues have developed a model that characterizes the parameters of the galactic warp, where it begins in the outer disk, how fast the warp is moving and the shape of the warp. The model has helped them determine that the warp, which doesn’t affect our own sun, but is passing our solar system now at speeds that allow it to make a full rotation around the galaxy every 450 million years, is not a result of the Milky Way’s own internal mass. Instead, it is the relic of gravitational tugging on the Milky Way’s disk by the nearby passage of a satellite galaxy, possibly the Sagittarius Dwarf Spheroidal Galaxy, about 3 billion years ago.

    “We can still see the disk of our galaxy shaking as a result,” Anguiano said.

    The data the team collected from the new tools available to astronomers may be just the beginning of a new wave of discoveries about our universe and how it came to be.

    “We’re entering an age in astronomy, especially in galactic astronomy, in which we are measuring the movement of the stars at such a level of precision that we can map their past orbital paths and start to understand how they may have been affected at earlier times and how other galaxies approaching our own interacted with stars as they were being born,” Anguiano said. “This level of precision has opened a new door to understanding our galaxy’s past and how it was assembled.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UVA campus

    The University of Virginia (U.Va. or UVA), frequently referred to simply as Virginia, is a public-private flagship and research university. Founded in 1819 by Declaration of Independence author Thomas Jefferson, UVA is known for its historic foundations, student-run honor code, and secret societies.

    UNESCO designated UVA as America’s first and only collegiate World Heritage Site in 1987, an honor shared with nearby Monticello. The university was established in 1819, and its original governing Board of Visitors included Thomas Jefferson, James Madison, and James Monroe. Monroe was the sitting President of the United States at the time of its foundation. Former Presidents Jefferson and Madison were UVA’s first two rectors and the Academical Village and original courses of study were conceived and designed by Jefferson.

    The university’s research endeavors are highly recognized. In 2015, Science honored UVA faculty for discovering two of its top 10 annual scientific breakthroughs; from the fields of Medicine and Psychology. UVA is one of 62 institutions in the Association of American Universities (AAU), an organization of preeminent North American research universities. It is the only AAU member university located in Virginia. UVA is classified as a Research University with Very High Research by the Carnegie Foundation, and is considered Virginia’s flagship university by the College Board. The university was the first non-founding member, and the first university of the American South, to attain AAU membership in 1904. UVA has been referred to as a “Public Ivy” by various sources. Companies founded by UVA students and alumni, such as Reddit, generate more than $1.6 trillion in annual revenue – equivalent to an economy the size of Canada, 10th-largest in the world.

    UVA’s academic strength is broad, with 121 majors across the eight undergraduate and three professional schools.[16] Students compete in 26 collegiate sports and UVA leads the Atlantic Coast Conference in men’s NCAA team national championships with 17. UVA is second in women’s NCAA titles with 7. UVA was awarded the Capital One Cup in 2015 after fielding the top overall men’s athletics programs in the nation.

    Students come to attend the university in Charlottesville from all 50 states and 147 countries.[18][19][20] The historical campus occupies 1,682-acre (2.6 sq mi; 680.7 ha), many of which are internationally protected by UNESCO and widely recognized as some of the most beautiful collegiate grounds in the country. UVA additionally maintains 2,913-acre (4.6 sq mi; 1,178.8 ha) southeast of the city, at Morven Farm. The university also manages the College at Wise in Southwest Virginia, and until 1972 operated George Mason University and the University of Mary Washington in Northern Virginia.

     
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