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  • richardmitnick 10:35 pm on August 19, 2014 Permalink | Reply
    Tags: , , , , , Sloan Digital Sky Survey   

    From Kavli: “New Survey Begins Mapping Nearby Galaxies “ 

    KavliFoundation

    The Kavli Foundation

    August 18, 2014
    (Originally published by Kavli IPMU)

    A new survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) has been launched that will greatly expand our understanding of galaxies, including the Milky Way, by charting the internal structure and composition of an unprecedented sample of 10,000 galaxies.

    Apache Point Observatory
    Apache Point Observatory

    MaNGA is a part of the fourth generation Sloan Digital Sky Survey (SDSS-IV) and will make maps of stars and gas in galaxies to determine how they have grown and changed over billions of years, using a novel optical fiber bundle technology that can take spectra of all parts of a galaxy at the same time.

    Sloan Digital Sky Survey Telescope
    Sloan Digital Sky Survey Telescope

    The new survey represents a collaboration of more than 200 astronomers at more than 40 institutions on four continents. With the new technology, astronomers will gain a perspective on the building blocks of the universe with a statistical precision that has never been achieved before.

    “Because the life story of a galaxy is encoded in its internal structure—a bit like the way the life story of a tree is encoded in its rings—MaNGA would, for the first time, enable us to map the evolutionary histories of galaxies of all types and sizes, living in all kinds of environments,” said Kevin Bundy, MaNGA’s Principal Investigator from the Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo.

    image
    Previously, SDSS has mapped the universe across billions of light-years, focusing on the time from 7 billion years after the Big Bang to the present and the time from 2 billion years to 3 billion years after the Big Bang. SDSS-IV will focus on mapping the distribution of galaxies and quasars 3 billion years to 7 billion years after the Big Bang, a critical time when dark energy is thought to have started to affect the expansion of the Universe. Image credit: SDSS collaboration and Dana Berry / SkyWorks Digital, Inc. WMAP cosmic microwave background (Credit: NASA/WMAP Science Team)

    This new survey will provide a vast public database of observations that will significantly expand astronomer’s understanding of how tiny differences in the density of the early universe evolved over billions of years into the rich structure of galaxies today. This cosmic story includes the journey of our own Milky Way galaxy from its origins to the birth of our sun and solar system, and eventually the necessary conditions that gave rise to life on Earth.

    “MaNGA will not only teach us about what shapes the appearance of normal galaxies,” said SDSS Project Scientist, Matthew Bershady from the University of Wisconsin, Madison. “It will also almost surely surprise us with new discoveries about the origin of dark matter, super-massive black holes, and perhaps even the nature of gravity itself.” This potential comes from MaNGA’s ability to paint a complete picture of each galaxy using an unprecedented amount of spectral information on the chemical composition and motions of stars and gas.

    To realize this potential, the MaNGA team has developed new technologies for bundling sets of fiber-optic cables into tightly-packed arrays that dramatically enhance the capabilities of existing instrumentation on the 2.5-meter Sloan Foundation Telescope in New Mexico. Unlike nearly all previous surveys, which combine all portions of a galaxy into a single spectrum, MaNGA will obtain as many as 127 different measurements across the full extent of every galaxy. Its new instrumentation enables a survey of more than 10,000 nearby galaxies at twenty times the rate of previous efforts, which did one galaxy at a time.

    But local galaxy studies are far from the only astronomical topic the new SDSS will explore. Another core program called APOGEE-2 will chart the compositions and motions of stars across the entire Milky Way in unprecedented detail, using a telescope in Chile along with the existing Sloan Foundation Telescope.

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    The new SDSS will measure spectra at multiple points in the same galaxy, using a newly created fiber bundle technology. The left-hand side shows the Sloan Foundation Telescope and a close-up of the tip of the fiber bundle. The bottom right illustrates how each fiber will observe a different section of each galaxy. The image (from the Hubble Space Telescope) shows one of the first galaxies that the new SDSS has measured. The top right shows data gathered by two fibers observing two different part of the galaxy, showing how the spectrum of the central regions differs dramatically from outer regions. Image Credit: David Law, SDSS collaboration, and Dana Berry / SkyWorks Digital, Inc. Hubble Space Telescope (Credit:(http://hubblesite.org/newscenter/archive/releases/2008/16/image/cg/): NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University))

    And the new SDSS will continue to improve our understanding of the Universe as a whole. The third core program, eBOSS, will precisely measure the expansion history of the Universe through 80% of cosmic history, back to when the Universe was less than three billion years old. These new detailed measurements will help to improve constraints on the nature of dark energy, the most mysterious experimental result in modern physics.

    “SDSS has a proud history of fostering a breadth of cosmic discoveries that connect a deep understanding of the origins of the universe with key insights on the nature of galaxies and the makeup of our own Milky Way,” said Hitoshi Murayama, Director of the Kavli IPMU. “We are delighted to be a part of this endeavor to understand the Universe in the broadest sense, and particularly happy to see our Kevin Bundy playing such a crucial role to make it all happen.”

    With new technology and surveys like MaNGA and the continuing generous support of the Alfred P. Sloan Foundation and participating institutions, the SDSS will remain one of the world’s most productive astronomical facilities. Science results from the SDSS will continue to reshape our view of the fundamental constituents of the cosmos, the universe of galaxies, and our home in the Milky Way.

    ABOUT THE SLOAN DIGITAL SKY SURVEY

    Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah.

    SDSS-IV is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS Collaboration including the Carnegie Institution for Science, Carnegie Mellon University, the Chilean Participation Group, Harvard-Smithsonian Center for Astrophysics, Instituto de Astrofisica de Canarias, The Johns Hopkins University, Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) / University of Tokyo, Lawrence Berkeley National Laboratory, Leibniz Institut fur Astrophysik Potsdam (AIP),Max-Planck-Institut fur Astrophysik (MPA Garching), Max-Planck-Institut fur Extraterrestrische Physik (MPE), Max-Planck-Institut fur Astronomie (MPIA Heidelberg), National Astronomical Observatory of China, New Mexico State University, New York University, The Ohio State University, Pennsylvania State University, Shanghai Astronomical Observatory, United Kingdom Participation Group, Universidad Nacional Autonoma de Mexico, University of Arizona, University of Colorado Boulder, University of Portsmouth, University of Utah, University of Washington, University of Wisconsin, Vanderbilt University, and Yale University.

    SDSS Website – http://www.sdss.org/

    See the full article, with video and additional material here.

    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

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  • richardmitnick 12:59 pm on January 8, 2014 Permalink | Reply
    Tags: , , , , , Sloan Digital Sky Survey   

    From NRAO: “Dwarf Galaxies Give Clues to Origin of Supermassive Black Holes” 

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    Monday, 6 January 2014
    Contact: Dave Finley, Public Information Officer
    (575) 835-7302; dfinley@nrao.edu

    Poring through data from a large sky survey, astronomers have found more than 100 small, dwarf galaxies with characteristics indicating that they harbor massive black holes feeding on surrounding gas. The discovery confounds a common assumption that only much larger galaxies hold such monsters, and may help resolve the question of how such black holes originated and grew in the early Universe.

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    Dwarf galaxy NGC 4395, about 13 million light-years from Earth, known to harbor a black hole some 300,000 times more massive than the Sun. It is a prototypical example of a small galaxy once thought to be too small to contain such a black hole.
    CREDIT: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration; NRAO/AUI/NSF.

    Another view
    image
    An ultraviolet image of NGC 4395 taken with GALEX.
    Credit: GALEX/NASA

    “We’ve shown that even small galaxies can have massive black holes and that they may be more common than previously thought,” said Amy Reines, of the National Radio Astronomy Observatory (NRAO). “This is really exciting because these little galaxies hold the clues to the origin of the first ‘seeds’ of supermassive black holes in the early Universe,” she said. Reines and her colleagues presented their findings to the American Astronomical Society’s meeting in Washington, DC.

    Black holes are concentrations of mass so dense that not even light can escape their gravitational pull. Nearly all “full-sized” galaxies are known to have supermassive black holes, millions or billions of times more massive than the Sun, at their cores. Until recently, however, smaller galaxies were thought not to harbor massive black holes.

    Reines, along with Jenny Greene of Princeton University and Marla Geha of Yale University, analyzed data from the Sloan Digital Sky Survey, and found more than 100 dwarf galaxies whose patterns of light emission indicated the presence of massive black holes and their feeding process.

    “The galaxies are comparable in size to the Magellanic Clouds, dwarf satellite galaxies of the Milky Way,” Geha said. “Previously, such galaxies were thought to be too small to have such massive black holes,” she added.

    In the nearby Universe, astronomers have found a direct relationship between the mass of a galaxy’s central black hole and a “bulge” in its center. This indicates that the black holes and the bulges may have affected each others’ growth.

    “Finding these small galaxies with massive black holes is an important step toward understanding how galaxies and black holes developed together,” Greene said. “These dwarf galaxies are the smallest known to host massive black holes and can provide clues to how supermassive black holes get started in the first place,” she added.

    While today’s larger galaxies hold black holes millions or billions of times more massive than the Sun, the dwarf galaxies in the new study have black holes roughly 100,000 times the Sun’s mass. The supermassive and massive black holes are distinct from stellar-mass black holes — only a few times the mass of the Sun — that result from the collapse of a massive star at the end of its “normal” life.

    Still unknown, the scientists said, is whether the massive black holes initially began as the remnants of extremely massive early stars or some other scenario of collapsing mass.

    “Getting a good census of dwarf galaxies with massive black holes is an important first step to resolving this question,” Reines said.

    See the full article here.

    The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA)*.

    NRAO ALMA
    NRAO ALMA

    NRAO GBT
    NRAO GBT

    NRAO VLA
    NRAO VLA

    The NRAO is building two new major research facilities in partnership with the international community that will soon open new scientific frontiers: the Atacama Large Millimeter/submillimeter Array (ALMA), and the Expanded Very Large Array (EVLA). Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).
    *The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!

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


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  • richardmitnick 5:11 pm on February 19, 2013 Permalink | Reply
    Tags: , , , , , Sloan Digital Sky Survey,   

    From Symmetry: “Spectroscopy – explain it in 60 seconds” 

    scpe
    Illustration: Sandbox Studio, Chicago; Image courtesy of: ESA/Hubble & NASA

    February 18, 2013
    Klaus Honscheid and Eric Huff, Center for Cosmology and AstroParticle Physics, The Ohio State University

    Spectroscopy is a technique that astronomers use to measure and analyze the hundreds of colors contained in the light emitted by stars, galaxies and other celestial objects.

    spec
    Analysis of white light by dispersing it with a prism is an example of spectroscopy

    “Ordinary telescopes show the directions in which objects are located but offer no information on how far away these objects are.

    Spectroscopic surveys make use of the fact that, as light travels to us from distant galaxies, it gets stretched out by the expanding universe and appears redder. By measuring the light spectrum of a galaxy, scientists can determine its redshift and thus its distance.

    The largest spectroscopic survey to date is the Baryon Oscillation Spectroscopic Survey, which is being carried out at the Sloan telescope and will record the spectra of 1.5 million galaxies by the time it’s completed in 2014. BOSS will offer insight into one of the biggest mysteries of the universe: dark energy, the enigmatic force that has accelerated the universe’s expansion over the last 5 billion years.

    scope
    The Sloan Foundation 2.5-m Telescope at the Apache Point Observatory

    An even more ambitious spectroscopic survey to measure the redshifts of 20 million galaxies is now being developed. In a few years, when this new spectroscopic survey experiment goes online, we will finally realize the massive scale of cosmic cartography necessary for truly sensitive measurements of dark energy.”

    See the original article here.

    You can explore the full explain it in 60 seconds archive. It is worth your time.

    Symmetry is a joint Fermilab/SLAC publication.

     
  • richardmitnick 12:50 pm on August 8, 2012 Permalink | Reply
    Tags: , , , , , , , Sloan Digital Sky Survey   

    From Berkeley Lab: “The First Public Data Release from BOSS, the Baryon Oscillation Spectroscopic Survey” 


    Berkeley Lab

    Led by Berkeley Lab scientists, the Sloan Digital Sky Survey’s BOSS is bigger than all other spectroscopic surveys combined for measuring the universe’s large-scale structure

    sdssiii

    image2

    August 08, 2012
    Paul Preuss

    “The Third Sloan Digital Sky Survey (SDSS-III) has issued Data Release 9 (DR9), the first public release of data from the Baryon Oscillation Spectroscopic Survey (BOSS). In this release BOSS, the largest of SDSS-III’s four surveys, provides spectra for 535,995 newly observed galaxies, 102,100 quasars, and 116,474 stars, plus new information about objects in previous Sloan surveys (SDSS-I and II).

    ‘This is just the first of three data releases from BOSS,’ says David Schlegel of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), an astrophysicist in the Lab’s Physics Division and BOSS’s principal investigator. ‘By the time BOSS is complete, we will have surveyed more of the sky, out to a distance twice as deep, for a volume more than five times greater than SDSS has surveyed before – a larger volume of the universe than all previous spectroscopic surveys combined.’”

    See the full article here.

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

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  • richardmitnick 2:24 pm on June 28, 2012 Permalink | Reply
    Tags: , , , , , Sloan Digital Sky Survey   

    From Symmetry/Breaking: “Scientists Discover that Milky Way Was Struck Some 100 Million Years Ago, Still Rings Like a Bell” 

    June 28, 2012 | 11:24 am

    Fermi National Accelerator Laboratory issued the following press release today.

    “Our galaxy, the Milky Way, is a large spiral galaxy surrounded by dozens of smaller satellite galaxies. Scientists have long theorized that occasionally these satellites will pass through the disk of the Milky Way, perturbing both the satellite and the disk. A team of astronomers from Canada and the United States have discovered what may well be the smoking gun of such an encounter, one that occurred close to our position in the galaxy and relatively recently, at least in the cosmological sense.

    mw
    Stars in the disk of the Milky Way move up and down at a speed of about 20-30 kilometers per second while orbiting the center of the galaxy at a brisk 220 kilometers per second. Image: Fermilab

    ‘We have found evidence that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago,’ said Larry Widrow, professor at Queen’s University in Canada. ‘We clearly observe unexpected differences in the Milky Way’s stellar distribution above and below the Galaxy’s midplane that have the appearance of a vertical wave — something that nobody has seen before.’

    The discovery is based on observations of some 300,000 nearby Milky Way stars by the Sloan Digital Sky Survey. Stars in the disk of the Milky Way move up and down at a speed of about 20-30 kilometers per second while orbiting the center of the galaxy at a brisk 220 kilometers per second. Widrow and his four collaborators from the University of Kentucky, the University of Chicago and Fermi National Accelerator Laboratory have found that the positions and motions of these nearby stars weren’t quite as regular as previously thought.”

    The results have been published in The Astrophysical Journal Letters.

    See the full article here.

    symmetrybreaking is a joint Fermilab/SLAC publication

     
  • richardmitnick 1:43 pm on February 1, 2012 Permalink | Reply
    Tags: , , , Sloan Digital Sky Survey   

    From isgtw: “Calculating the Universe” 

    PAUL PREUSS
    FEBRUARY 1, 2012

    “Since 2000, the three Sloan Digital Sky Surveys (SDSS I, II, and III) have surveyed well over a quarter of the night sky, producing the biggest 3-D color map of the Universe ever made. Now, scientists have used this visual information for the most accurate computation yet of how matter clumped together – from a time when the universe was only half its present age until now.

    ‘The way galaxies cluster together over vast expanses of the sky tells us how both ordinary visible matter and underlying invisible dark matter are distributed, across space and back in time,’ said Shirley Ho, an astrophysicist at Lawrence Berkeley National Laboratory and Carnegie Mellon University who led the work. ‘The distribution gives us cosmic rulers to measure how the universe has expanded, and a basis for calculating what’s in it: how much dark matter, how much dark energy, even the mass of the hard-to-see neutrinos it contains. What’s left over is the ordinary matter and energy we’re familiar with.’ “

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    This image shows over a million luminous galaxies at redshifts indicating times when the universe was between seven and eleven billion years old, from which the sample in the current studies was selected. Image by David Kirkby of the University of California at Irvine and the SDSS collaboration.

    sdss III
    SDSS-III

    See the full article here. This is really big stuff.

     
  • richardmitnick 4:07 pm on January 11, 2012 Permalink | Reply
    Tags: , , , , , , Sloan Digital Sky Survey   

    From Berkeley Labs: “Calculating What’s in the Universe from the Biggest Color 3-D Map” 


    Berkeley Lab

    Berkeley Lab scientists and their Sloan Digital Sky Survey colleagues use galactic brightness to build a precision model of the cosmos

    “Since 2000, the three Sloan Digital Sky Surveys (SDSS I, II, III) have surveyed well over a quarter of the night sky and produced the biggest color map of the universe in three dimensions ever. Now scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and their SDSS colleagues, working with DOE’s National Energy Research Scientific Computing Center (NERSC) based at Berkeley Lab, have used this visual information for the most accurate calculation yet of how matter clumps together – from a time when the universe was only half its present age until now.

    i3
    The bottom panel shows the sky coverage of the final SDSS imaging survey, including data from SDSS I, II, and III.
    SDSS imaging covered slightly more than 1/3 of the sky, concentrated in the northern and southern Galactic caps (above and below the plane of the galaxy). In this image, stripes are radiating out from these caps; these stripes are areas imaged by the SEGUE survey, extending toward the plane of the Milky Way. Each orange dot in this map is a galaxy.
    The sequence of zooms in the upper panels zeroes in on the star-forming nebula NGC 604 in the nearby (2.5 million light years) galaxy Messier 33. In all, the SDSS imaging map shown here contains more than a trillion pixels, each one imaged in five colors. Credit: M. Blanton and the SDSS-III collaboration

    i7
    Slices through the SDSS 3-dimensional map of the distribution of galaxies. Earth is at the center, and each point represents a galaxy, typically containing about 100 billion stars. Galaxies are colored according to the ages of their stars, with the redder, more strongly clustered points showing galaxies that are made of older stars. The outer circle is at a distance of two billion light years. The region between the wedges was not mapped by the SDSS because dust in our own Galaxy obscures the view of the distant universe in these directions. Both slices contain all galaxies within -1.25 and 1.25 degrees declination. Credit: M. Blanton and the Sloan Digital Sky Survey.

    ‘The way galaxies cluster together over vast expanses of the sky tells us how both ordinary visible matter and underlying invisible dark matter are distributed, across space and back in time,’ says Shirley Ho, an astrophysicist at Berkeley Lab and Carnegie Mellon University, who led the work. ‘The distribution gives us cosmic rulers to measure how the universe has expanded, and a basis for calculating what’s in it: how much dark matter, how much dark energy, even the mass of the hard-to-see neutrinos it contains. What’s left over is the ordinary matter and energy we’re familiar with.'”

    See the full article here. This is a huge article, with many links to related web sites.

    A US Department of Energy National Laboratory Operated by the University of California

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  • richardmitnick 4:14 pm on January 9, 2012 Permalink | Reply
    Tags: , , , , Sloan Digital Sky Survey   

    From Berkeley Lab: “Clearest Picture Yet of Dark Matter Points the Way to Better Understanding of Dark Energy” 


    Berkeley Lab

    Scientists at Fermilab and Berkeley Lab build the biggest maps of dark matter yet, using methods that will improve ground-based surveys

    JANUARY 09, 2012
    Paul Preuss

    “Two teams of physicists at the U.S. Department of Energy’s Fermilab and Lawrence Berkeley National Laboratory (Berkeley Lab) have independently made the largest direct measurements of the invisible scaffolding of the universe, building maps of dark matter using new methods that, in turn, will remove key hurdles for understanding dark energy with ground-based telescopes.

    The teams’ measurements look for tiny distortions in the images of distant galaxies, called cosmic shear, caused by the gravitational influence of massive, invisible dark matter structures in the foreground. Accurately mapping out these dark-matter structures and their evolution over time is likely to be the most sensitive of the few tools available to physicists in their ongoing effort to understand the mysterious space-stretching effects of dark energy.

    Both teams depended upon extensive databases of cosmic images collected by the Sloan Digital Sky Survey (SDSS), which were compiled in large part with the help of Berkeley Lab and Fermilab.

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    Layering photos of one area of sky taken at various time periods, a process called coaddition, can increase the sensitivity of the images six-fold, by removing errors and enhancing faint light signals. The image on the left shows a single picture of galaxies from SDSS Stripe 82. The image on the right shows the same area after layering, increasing the number of visible, distant galaxies. (Image credit SDSS)

    See the full article here.

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

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    Fermilab continues to be a great source of strength in the U.S. Basic Research Community.

     
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