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  • richardmitnick 1:06 pm on June 25, 2019 Permalink | Reply
    Tags: "The Low Density of Some Exoplanets is Confirmed", , , , CfA, , Kepler-9 and its planets Kepler-9b and Kepler-9c   

    From Harvard-Smithsonian Center for Astrophysics: “The Low Density of Some Exoplanets is Confirmed” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    June 21, 2019

    The Kepler mission and its extension, called K2, discovered thousands of exoplanets.

    NASA/Kepler Telescope, and K2 March 7, 2009 until November 15, 2018

    It detected them using the transit technique, measuring the dip in light intensity whenever an orbiting planet moved across the face of its host star as viewed from Earth.

    Planet transit. NASA/Ames

    Transits can not only measure the orbital period, they often can determine the size of the exoplanet from the detailed depth and shape of its transit curve and the host star’s properties. The transit method, however, does not measure the mass of the planet. The radial velocity method, by contrast, which measures the wobble of a host star under the gravitational pull of an orbiting exoplanet, allows for the measurement of its mass. Knowing a planet’s radius and mass allows for the determination of its average density, and hence clues to its composition.

    Radial Velocity Method-Las Cumbres Observatory

    About fifteen years ago, CfA astronomers and others realized that in planetary systems with multiple planets, the periodic gravitational tug of one planet on another will alter their orbital parameters. Although the transit method cannot directly measure exoplanet masses, it can detect these orbital variations and these can be modeled to infer masses. Kepler has identified hundreds of exoplanet systems with transit-timing variations, and dozens have been successfully modeled. Surprisingly, this procedure seemed to find a prevalence of exoplanets with very low densities. The Kepler-9 system, for example, appears to have two planets with densities respectively of 0.42 and 0.31 grams per cubic centimeter. (For comparison, the rocky Earth’s average density is 5.51 grams per cubic centimeter, water is, by definition, 1.0 grams per cubic centimeter, and the gas giant Saturn is 0.69 grams per cubic centimeter.) The striking results cast some doubt on one or more parts of the transit timing variation methodology and created a long-standing concern.

    CfA astronomers David Charbonneau, David Latham, Mercedes Lopez-Morales, and David Phillips, and their colleagues tested the reliability of the method by measuring the densities of the Kepler-9 planets using the radial velocity method, its two Saturn-like planets being among a small group of exoplanets whose masses can be measured (if just barely) with either technique.

    2
    An artist’s depiction of Kepler-9 and its planets Kepler-9b and Kepler-9c. NASA

    They used the HARPS-N spectrometer on the Telescopio Nazionale Galileo in La Palma in sixteen observing epochs; HARPS-N can typically measure velocity variations with an error as tiny as about twenty miles an hour. Their results confirm the very low densities obtained by the transit-timing method, and verify the power of the transit-variation method.

    Harps North at Telescopio Nazionale Galileo –

    Telescopio Nazionale Galileo a 3.58-meter Italian telescope, located at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain, Altitude 2,396 m (7,861 ft)

    Science paper:
    HARPS-N Radial Velocities Confirm the Low Densities of the Kepler-9 Planets
    MNRAS

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 2:57 pm on June 7, 2019 Permalink | Reply
    Tags: "The Co-Evolution of Galaxies and Supermassive Black Holes", , , , CfA,   

    From Harvard-Smithsonian Center for Astrophysics: “The Co-Evolution of Galaxies and Supermassive Black Holes” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    1
    An Illustris-TNG simulation of the stellar content of the universe today on the largest scales showing a projection of stars across a 150 million light-years. Scientists using the code have been able to trace the co-evolution of galaxies and their supermassive black holes. The TNG Collaboration

    The formation and growth of galaxies in the early universe is a key research topic for future giant telescopes like the Giant Magellan Telescope and space missions like the James Webb Space Telescope.

    Giant Magellan Telescope, 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

    NASA/ESA/CSA Webb Telescope annotated

    Meanwhile, computer simulations of cosmic galaxy development have made considerable progress in our understanding. They show that details of galaxy development are closely tied to the properties of the galaxies, like their sizes and star formation rates. These properties are in turn regulated by the galaxies’ gas content, the gas motions (primarily the angular momentum), and some still uncertain mechanisms that regulate star formation like feedback from the nuclear black hole. Finally, there is growing evidence for correlations between the properties of a supermassive black hole and its host galaxy.

    Black holes with millions or even billions of solar masses are found in the centers of most galaxies. The most powerfully active nuclear black holes are in quasars and these have been spotted as far away as the epoch when the universe was less than a billion years old, suggesting that the galaxy- black hole symbiosis was already underway at this early time. Accreting black holes can emit powerful jets or winds that reverse the accretion and drive material outward, sometimes quenching the star formation. These and other lines of evidence help to clarify the co-evolution mechanisms between black holes and galaxies and reveal the joint evolution of the galaxy and the supermassive black hole populations.

    CfA astronomers Lars Hernquist and Rainer Weinberger and their colleagues used the large-scale hydrodynamic simulation called IllustrisTNG to trace the development of galaxies and their black holes. The code is able to model the evolution of a wide range of black hole and galaxy properties as the universe ages. They successfully reproduce the observed correlation between star formation rate and galaxy mass. They find, among numerous other trends, that quiescent galaxies (those no longer actively making stars) first go through a phase of shrinking in size before they undergo a quenching event; they also find that in the cosmic epoch of peak star formation (about ten billion years ago) as many as twenty percent of galaxies hosted an active supermassive black hole.

    science paper:
    Linking Galaxy Structural Properties and Star Formation Activity to Black Hole Activity with IllustrisTNG
    MNRAS

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 3:29 pm on May 11, 2019 Permalink | Reply
    Tags: "Suppressed Star Formation in the Early Universe", , , , CfA, , Massive cluster SPT-CLJ0421   

    From Harvard Smithsonian Center for Astrophysics: “Suppressed Star Formation in the Early Universe” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    May 10, 2019

    6
    A galaxy cluster map portraying the density of galaxies members in the massive cluster SPT-CLJ0421. Astronomers studying five such clusters in the epoch about 4.5 billion years after the big bang conclude that their star formation is quenched. Symbols show the positions of individual galaxies and the cross marks the position of the SPT detection. Credit: Strazzullo et al. 2019

    Massive clusters of galaxies, some with more mass than a hundred Milky Way galaxies, have been detected from cosmic epochs as early as about three billion years after the big bang.

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    Map of voids and superclusters within 500 million light years from Milky Way 8/11/09 http://www.atlasoftheuniverse.com/nearsc.html Richard Powell

    These six images represent the potential for new images and discoveries housed in the Chandra Data Archive. To celebrate October as American Archive Month, these images – which include supernova remnants, pulsars, black holes, and clusters of galaxies – are being released. Each image represents data that are available to both the professional scientific community as well as the general public.

    Their ongoing star formation makes them bright enough to be detected at these distances. These kinds of clusters were predicted by simulations of cosmological evolution but their properties are very uncertain. Astronomers piecing together the evolution of stars in the universe are particularly interested in these clusters because of their abundance of stars and activity.

    Star formation in galaxies is by no means a steady process. Not only can there be bursts of activity, prompted perhaps by a collision with a neighboring galaxy, but the opposite can occur. Star formation can be self- limiting because its massive young stars produce winds and supernovae that can blow apart the natal molecular clouds and disable future star formation. Combined with the disruption induced by jets from an active nuclear supermassive black hole, this disruptive process is called quenching and is thought to be able to bring star formation to a halt. Whether or not this occurs in the early universe, and when and how it proceeds, is a key area of comic research.

    CfA astronomers Matt Ashby and Esra Bulbul are members of the South Pole Telescope (SPT) team that discovered and studies massive galaxy clusters in the early universe.

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago, the University of California, Berkeley, Case Western Reserve University, Harvard/Smithsonian Astrophysical Observatory, the University of Colorado Boulder, McGill University, The University of Illinois at Urbana-Champaign, University of California, Davis, Ludwig Maximilian University of Munich, Argonne National Laboratory, and the National Institute for Standards and Technology. It is funded by the National Science Foundation.

    They recently completed a follow-up study of star formation and the stellar populations in most distant clusters found in the SPT surveys. Using the IRAC camera on the Spitzer Space Telescope along with the Hubble Space Telescope Wide Field camera, they probed five clusters located in the epoch about 4.5 billion years after the big bang, a time when galaxies in general were particularly active in producing new stars.

    IRAC camera on the Spitzer space telescope

    NASA/Spitzer Infrared Telescope

    NASA/ESA Hubble WFC3

    NASA/ESA Hubble Telescope

    Clusters of this size are exceedingly rare at these distances, and this is the first such study ever done of them. Using the infrared colors of the galaxies in the selected SPT clusters, the scientists were able to characterize the stars and the star formation activity. The scientists found that, curiously, during this epoch the massive clusters tend to host a mixture of galaxy types with quiescent galaxies being quite common. Apparently in these quiescent cluster members the quenching of star formation has already occurred. The astronomers conclude that star formation can be efficiently suppressed in the central regions of the most massive clusters even in these early cosmic epochs when the most intense star formation is occurring.

    Science paper
    Galaxy populations in the most distant SPT-SZ clusters
    Astronomy and Astrophysics

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 12:41 pm on April 24, 2019 Permalink | Reply
    Tags: CfA, ,   

    From Harvard-Smithsonian Center for Astrophysics: “CfA Plays Central Role In Capturing Landmark Black Hole Image” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    Peter Edmonds
    Center for Astrophysics | Harvard & Smithsonian
    +1 617-496-1917
    pedmonds@cfa.harvard.edu

    Tyler Jump
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    +1 617-495-7462
    tyler.jump@cfa.harvard.edu

    1
    Messier 87 supermassive black hole depiction

    April 10, 2019

    The first image of a black hole ever taken was released April 10, 2019. This monumental achievement was made possible, in part, by key leadership and funding from the Center for Astrophysics | Harvard & Smithsonian (CfA).

    The Event Horizon Telescope, or EHT, is a global array of radio telescopes involving dozens of institutions and hundreds of scientists. The breakthrough discovery by the EHT is an image of Messier 87’s (M87’s) supermassive black hole in the center of the Virgo galaxy cluster, 55 million light years away. This black hole contains 6.5 billion times the mass of our Sun.

    EHT map

    Six papers are being published in the Astrophysical Journal Letters [see link below] today to describe this groundbreaking result.

    “This fulfills our dream to take the first picture of a black hole,” said the CfA’s Sheperd (Shep) S. Doeleman, the Director of the EHT. “We now have access to a cosmic laboratory of extreme gravity where we can test Einstein’s theory of General Relativity and challenge our fundamental assumptions about space and time.”

    Black holes are extremely compressed cosmic objects, containing extraordinary amounts of mass within a tiny region. This mass is shrouded by an event horizon, that is, the boundary beyond which nothing – not even light – can escape from the black hole’s powerful gravitational pull.

    The presence of these objects affects their surroundings in extreme ways, including warping spacetime and heating surrounding material to hundreds of billions of degrees. General Relativity predicts that a black hole will cast a circular shadow upon this bright, glowing material. The newly released image of M87 from the EHT reveals this shadow.

    “For decades, we have studied how black holes swallow material and power the hearts of galaxies,” says Ramesh Narayan, a Harvard University professor and a leader in EHT theory work. “To finally see a black hole in action, bending its nearby light into a bright ring, is a breathtaking confirmation that supermassive black holes exist and match the appearance expected from our simulations.”

    While astronomers have studied black holes for many years, making an image requires a new telescope with unprecedented resolution so it can detect fine details. To create this, the EHT combines the signals from an array of eight existing telescopes around the globe, including the Submillimeter Array (SMA), located on Maunakea in Hawai’i. As CfA engineer, Jonathan Weintroub, explains: “The resolution of the EHT depends on the separation between the telescopes, termed the baseline, as well as the short millimeter radio wavelengths observed. The finest resolution in the EHT comes from the longest baseline, which for M87 stretches from Hawai’i to Spain.” Weintroub, who co-coordinates the EHT’s Instrument Development Group, added: “To optimize the long baseline sensitivity, making detections possible, we developed a specialized system which adds together the signals from all available SMA dishes on Maunakea. In this mode, the SMA acts as a single EHT station.”

    After separately recording the signals at all eight telescopes, the data are flown to [two] locations* to be computationally combined into what would be measured by an Earth-sized telescope.

    MIT Haystack Observatory, Westford, Massachusetts, USA, Altitude 131 m (430 ft)


    Max Planck Institute for Radio Astronomy Bonn Germany

    *MIT Haystack Observatory, Westford, Massachusetts, USA and Max Planck Institute for Radio Astronomy Bonn Germany.

    “The EHT records millions of gigabytes of data from many telescopes that weren’t originally designed to work together,” explains Lindy Blackburn, who led the EHT team for data processing and calibration. “We developed multiple pathways to process and calibrate the data, using new algorithms to computationally stabilize the Earth’s atmosphere and to precisely align the signals from all sites within trillionths of a second.”

    Turning the EHT data into an image required developing new methods and procedures. “We weren’t ready to publish our images until after trying to break them in every way possible,” says Andrew Chael, a Harvard graduate student at the CfA, who developed a new imaging software library for the EHT. “To confirm our results, we compared images among four independent groups of scientists using three different imaging methods.” These tests were designed and led by Katie Bouman, a CfA postdoc who received her PhD in electrical engineering and computer science. Bouman explains, “We’re a melting pot of astronomers, physicists, mathematicians and engineers, and that’s what it took to achieve something once thought impossible.”

    Katie Bouman of Harvard Smithsonian Observatory for Astrophysics, headed to Caltech, with EHT hard drives from Messier 87

    Michael Johnson, a CfA astrophysicist who directs local EHT science and imaging efforts, is excited for the future. “Our image reveals that this enormous black hole — large enough to engulf the solar system — anchors a jet that extends tens of thousands of light years. Expanding the EHT may enable movies that reveal the dynamics of this living system, showing how the jet draws its energy from the black hole.”

    Besides those listed above, many others at the CfA have contributed in countless and invaluable ways. The following CfA scientists and engineers are co-authors of all six of the papers: Mislav Baloković, Lindy Blackburn, Katie Bouman, Roger Brissenden, Andrew Chael, Shep Doeleman, Joseph Farah, Mark Gurwell, David James, Michael Johnson, Garrett Keating, Jim Moran, Ramesh Narayan, Daniel Palumbo, Nimesh Patel, Dominic Pesce, Alexander W. Raymond, Jonathan Weintroub, Maciek Wielgus, and Ken Young.

    A list of biographies for CfA scientists working on the EHT are located here.

    The EHT and many of its key scientists are funded by a mixture of public (i.e. taxpayer) sources such as the National Science Foundation (NSF) and the Smithsonian Institution (SI) as well as the generosity of private entities including the Templeton Foundation and the Gordon and Betty Moore Foundation (GBMF). The NSF has funded steady advancement of the EHT over more than a decade and SI, administered through SAO, has provided funding for seven years. Doeleman has grants from the NSF and also from the GBMF and the John Templeton Foundation. The GBMF funded key technical developments starting in 2012 and was foundational in building the SAO group.

    SAO is one of the 13 stakeholder institutes for the EHT Board, and the CfA hosts the Array Operations Center for EHT observations. The SMA is a joint project between the Smithsonian Institution and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan. The Greenland Telescope, funded by ASIAA and SAO, joined the EHT for its second observing run in April, 2018.

    For more information on the EHT and this groundbreaking result, visit http://www.eventhorizontelescope.org and follow @ehtelescope on social media. The website for the CfA, which is organized into six research divisions to study the origin, evolution, and ultimate fate of the Universe, is http://www.cfa.harvard.edu.

    The full set of Astrophysical Journal Letters are here:

    https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT

    See the full article here .


    Katie Bouman takes the story to Caltech.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 12:15 pm on April 24, 2019 Permalink | Reply
    Tags: "Scientists Use Asteroid to Measure Smallest Star Size to Date", , , , CfA, , ,   

    From Harvard-Smithsonian Center for Astrophysics: “Scientists Use Asteroid to Measure Smallest Star Size to Date” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    April 16, 2019

    Amy Oliver
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    Fred Lawrence Whipple Observatory
    +1 617-495-7462
    amy.oliver@cfa.harvard.edu

    Tyler Jump
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    +1 617-495-7462
    tyler.jump@cfa.harvard.edu

    1

    Scientists in the VERITAS (Very Energetic Radiation Imaging Telescope Array System) Collaboration have published a paper in Nature Astronomy journal detailing the results of their work with the VERITAS array—located at the Center for Astrophysics’ Fred Lawrence Whipple Observatory in Amado, Arizona—to measure the smallest apparent size of stars in the night sky known to date.

    CfA/VERITAS, a major ground-based gamma-ray observatory with an array of four 12m optical reflectors for gamma-ray astronomy in the GeV – TeV energy range. Located at Fred Lawrence Whipple Observatory,Mount Hopkins, Arizona, US in AZ, USA, Altitude 2,606 m (8,550 ft)

    Measurements taken using the VERITAS telescopes revealed the diameter of a giant star located 2,674 light years from Earth. Taken on February 22, 2018, at the Whipple Observatory, data revealed the star to be 11 times the diameter of Earth’s Sun. Using the four 12-m gamma-ray telescopes of VERITAS, the team collected 300 images per second to detect the diffraction pattern in the shadow sweeping past the telescopes as the star TYC 5517-227-1 was occulted by the 60-km asteroid Imprinetta. “From these data, the brightness profile of the diffraction pattern of the star was reconstructed with high accuracy,” said Dr. Michael Daniel, Operations Manager, VERITAS. “This allowed us to determine the actual diameter of the star, and determine it to be a red giant, although it could previously be classified as ambiguous.”

    Three months later, on May 22, 2018, the team repeated the experiment when asteroid Penelope—diameter 88-km—occulted star TYC 278-748-1 located 700 light years from Earth. “Using the same formula for data collection and calculations, we determined this star to be 2.17 times the diameter Earth’s Sun,” said Daniel. “This direct measurement allowed us to correct an earlier estimation that placed the star’s diameter at 1.415 times that of our sun.”

    With almost any star on the night sky too distant from Earth to be directly measured using even the best of optical telescopes, scientists overcame these limitations using diffraction, which occurs when an object, like an asteroid, passes in front of a star, making a shadow called an occultation. “The incredibly faint shadows of asteroids pass over us every day,” explained Dr. Tarek Hassan, DESY. “But the rim of the shadow isn’t perfectly sharp. Instead, wrinkles of light surround the central shadow, like water ripples.”

    For VERITAS scientists, however, the task was not as easy as turning telescopes to the sky. “Asteroid occultations are difficult to predict,” said Daniel. “The only chance to catch the diffraction pattern is to make very fast snapshots when the shadow of the occultation sweeps across the telescope.”

    Astronomers have similarly used this method— which measures to an angular diameter of roughly one milliarcsecond—to measure angular sizes of stars occulted by Earth’s moon. “The trouble is that not many telescopes are large enough for the occultation method to measure the diffraction pattern with confirmed accuracy over the turbulence in the Earth’s atmosphere,” said Daniel. “VERITAS telescopes are uniquely sensitive as we use them primarily for observing faint light from very-high-energy gamma rays and cosmic rays. While they do not produce images as elegant as those from traditional optical telescopes, they see and capture fast variations of light, and we estimate that they can analyze stars up to ten times farther away with extreme accuracy than optical telescopes using the lunar occultation method can.”

    At its conclusion, the pilot study resulted in the direct measurement of the size of a star at the smallest angular scale in the night sky to date, and established a new method to determine the angular diameter of stars.

    About VERITAS

    VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a ground-based array of four, 12-m optical reflectors for gamma-ray astronomy located at the Center for Astrophysics | Harvard & Smithsonian, Fred Lawrence Whipple Observatory in Amado, Arizona. VERITAS is the world’s most sensitive very-high-energy gamma-ray observatory, and it detects gamma rays via the extremely brief flashes of blue “Cherenkov” light they create when they are absorbed in the Earth’s atmosphere.

    VERITAS is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation, and the Smithsonian Institution, and by NSERC in Canada.

    The VERITAS Collaboration consists of about 80 scientists from 20 institutions in the United States, Canada, Germany and Ireland.

    For more information about VERITAS visit http://veritas.sao.arizona.edu

    About DESY

    DESY is one of the world’s leading particle accelerator centers. Researchers use the large‐scale facilities at DESY to explore the microcosm in all its variety – ranging from the interaction of tiny elementary particles to the behavior of innovative nanomaterials and the vital processes that take place between biomolecules to the great mysteries of the universe. The accelerators and detectors that DESY develops and builds at its locations in Hamburg and Zeuthen are unique research tools. DESY is a member of the Helmholtz Association, and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent).

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 2:52 pm on March 20, 2019 Permalink | Reply
    Tags: Arizona, , CfA, , Muon Hunters 2: Return of the Ring- launches new Zooniverse citizen science project on March 14th 2019., VERITAS (Very Energetic Radiation Imaging Telescope Array System) gamma-ray observatory—a part of the Center for Astrophysics | Harvard & Smithsonian at the Fred Lawrence Whipple Observatory in , Zooniverse- the largest online platform for collaborative volunteer research   

    From Harvard-Smithsonian Center for Astrophysics: “Astrophysicists Once Again Seek Public’s Help to Unmask Muons Disguised as Gamma Rays” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    March 14, 2019

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

    Tyler Jump
    Public Affairs
    Center for Astrophysics | Harvard & Smithsonian
    +1 617-495-7462

    Minneapolis, MN & Amado, AZ –
    Muon Hunters 2: Return of the Ring, launches new Zooniverse citizen science project on March 14th, 2019.

    1
    After achieving highly successful results with their citizen science project, Muon Hunters, in 2017, scientists from the VERITAS (Very Energetic Radiation Imaging Telescope Array System) gamma-ray observatory—a part of the Center for Astrophysics | Harvard & Smithsonian at the Fred Lawrence Whipple Observatory in Amado, Arizona, USA—collaboration are once again asking the public for help in identifying hundreds of thousands of ring patterns produced in the cameras at VERITAS.

    Scientists use VERITAS to study gamma rays—the most energetic radiation in the universe—in order to explore the most exotic and extreme processes and physical conditions in space, like black holes, supernovae, and pulsars.

    Like the original project, Muon Hunters 2: Return of the Ring, will engage citizen scientists to identify patterns from muons—elementary particles like electrons, but heavier—and distinguish them from those produced by gamma rays, which the telescopes are designed to detect.

    “At VERITAS, we’re searching for gamma rays, which have the shortest wavelengths and the highest energy of any portion of the electromagnetic spectrum,” said Dr. Michael Daniel, Operations Manager, VERITAS. Muons are background that we have to get rid of so that we can more easily identify gamma rays, but they’re also useful to help us calibrate our telescopes. That’s where Muon Hunters, and the citizen scientists behind it, come in.”

    New to Muon Hunters 2 is the manner in which data will be presented to citizen scientists. Muon Hunters 2 will present images in a grid pattern, rather than individually, to bring additional efficiency to the project.

    “This time around, we’re trying to make both the project and the telescopes more efficient,” said Dr. Lucy Fortson, University of Minnesota Physics and Astronomy Professor and VERITAS researcher. “We use a machine to help the people work more efficiently and the classifications we get from citizen scientists help the machine to work more efficiently, so it’s a virtuous loop. Scientists will use the images that citizen scientists have identified to better train their computer programs to automatically tell the difference between muons and gamma rays.”

    Muon Hunters 2: The Return of the Ring, is run by Zooniverse, the largest online platform for collaborative volunteer research, in conjunction with VERITAS. Citizen science projects at Zooniverse allow researchers to efficiently and effectively comb through large amounts of complex data utilizing the enthusiastic efforts of millions of volunteers from around the world. Other current Zooniverse projects include Snapshot Safari, in which volunteers identify wildlife to help scientists understand the diversity and dynamics of wildlife populations across the African continent.

    The original Muon Hunters project welcomed 6,107 citizen scientists who made 2,161,338 classifications of 135,000 objects. “We are hoping to have as many, if not more, classifications than we had in the original project,” said Fortson. “The more data we get, the more efficient we can be, and that’s great for both the scientists and the machines.”

    Citizen scientists can become Muon Hunters here.

    About VERITAS

    VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a ground-based array of four, 12-m optical reflectors for gamma-ray astronomy located at the Center for Astrophysics | Harvard & Smithsonian, Fred Lawrence Whipple Observatory in Amado, Arizona. VERITAS detects gamma rays via the extremely brief flashes of blue “Cherenkov” light they create when they are absorbed in the Earth’s atmosphere.

    VERITAS is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation, and the Smithsonian Institution, and by NSERC in Canada.

    The VERITAS Collaboration consists of about 80 scientists from 20 institutions in the United States, Canada, Germany and Ireland.

    For more information about VERITAS visit http://veritas.sao.arizona.edu

    About Muon Hunters

    Muon Hunters is a citizen science-based data collection and identification project led by the University of Minnesota and Zooniverse. The project receives data from VERITAS telescopes and direct support from specific VERITAS collaborating institutions including the University of California-Los Angeles; University of California-Santa Cruz; McGill University, Canada; Deutsches Electron-Synchrotron Laboratory, Berlin, Germany; Barnard College/Columbia University; Cal State University – East Bay; University College Dublin, Ireland; and the Center for Astrophysics | Harvard & Smithsonian. In addition, Muon Hunters is supported by the ASTERICS program of the European Union.

    For more information about Muon Hunters, visit http://www.muonhunters.org

    For more information, contact:
    Dr. Lucy Fortson
    Zooniverse
    lffortson@gmail.com

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 1:56 pm on March 15, 2019 Permalink | Reply
    Tags: "Bright X-Ray Galactic Nuclei", , , , , CfA, ,   

    From Harvard-Smithsonian Center for Astrophysics: “Bright X-Ray Galactic Nuclei” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    1
    A Chandra X-Ray Observatory image of a field of galaxies in the costellation Bootes. A new study of 703 galaxies with supermassive black holes in this field finds that although infrared from dust and X-ray emission from the nucleus tend to be correlated, the infrared emitted by the supermassive black holes is not well correlated with the dust, suggesting the role of our viewing angle of a torus around the black hole nuclei. X-ray: NASA/CXC/CfA/R.Hickox et al.; Moon: NASA/JPL

    All massive galaxies are believed to host supermassive black holes (SMBH) at their centers that grow by accreting mass from their environment. The current picture also imagines that the black holes grow in size as their host galaxy evolves, perhaps because galaxy evolution includes accretion triggered, for example, by galaxy mergers. This general picture has been substantiated by two lines of data.

    The peak epoch of black hole accretion can be measured by observations of nuclear activity, and coincides with the peak epoch of star formation in the universe about ten billion years after the big bang. Star formation is associated with disruptions that stir up the gas and induce accretion. Moreover, the local universe shows a tight correlation between SMBH mass, host galaxy bulge mass, and the spread of stellar velocities. These methods (but with weaker confirmation) can similarly estimate the sizes of SMBH in galaxies in the earlier universe, and find that SMBH growth and galaxy growth are co-evolutionary processes. Indeed, it seems the processes may regulate each other over time to produce the galaxy and SMBH sizes we observe today.

    Both central black hole growth and star formation are fed by the abundance of molecular gas and dust that can be traced by the infrared emitted by the dust.

    Dust grains, heated by the radiation from young stars and AGN accretion, emit strongly in the infrared. Since AGN activity also produces X-rays, the expectation is that AGN should track strong dust emission and that X-ray and infrared emission should be correlated.

    CfA astronomer Mojegan Azadi was a member of a team that examined 703 galaxies with active SMBH nuclei using both X-ray data from Chandra and infrared from Spitzer and Herschel, the largest sample to date making this comparison. Although the team did find a trend consistent with the infrared correlating with AGN X-ray activity over a wide range of cases, they did not find one when compared with the AGN’s infrared (not- X-ray) contributions.

    Since the AGN infrared comes largely from a dusty emitting torus around the SMBH, the difference could point to the role of the angle with which we view the torus. These results help to refine the current models of AGN activity, but the authors note that more sensitive, deeper observations should be able to sort out more clearly the physical processes associated with the AGN.

    Science paper:
    Infrared Contributions of X-Ray Selected Active Galactic Nuclei in Dusty Star-forming Galaxies
    Arianna Brown, Hooshang Nayyeri, Asantha Cooray, Jingzhe Ma, Ryan C. Hickox, and Mojegan Azadi
    The Astrophysical Journal

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 8:44 am on March 9, 2019 Permalink | Reply
    Tags: "First Detection of the Pre-Biotic Molecule Glycolonitrile in Space", Adenine- one of the four constituent bases of nucleic acids is thought to have formed from one of the two known two-ring nitrogen heterocycles- glycolonitrile (HOCH2CN), Astronomers have calculated that glycolonitrile could then be broken apart by ultraviolet light, CfA, , Glycolonitrile itself however has not been reported leaving a step in the theory of the formation of nucleic acids unconfirmed., Heterocyclic molecules are those containing atoms of at least two different elements (plus hydrogen) arranged in a ring structure, , Nitrogen heterocycles are key components in biological nucleic acids, Target: solar-type protostar IRAS16293-2422B, The team concludes that some other chemical pathways must be operative, The team searched for the characteristic spectral signature of glycolonitrile in three frequency bands of ALMA and found thirty-five of its transitions that were unambiguous, This critical chemical has now been measured and the theory is in general on the right track   

    From Harvard-Smithsonian Center for Astrophysics: “First Detection of the Pre-Biotic Molecule Glycolonitrile in Space” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    March 8, 2019

    1
    A false-color infrared image of the molecular cloud containing the young star IRAS16293-2422. The marked square shows the region where the star is located, and the insert illustrates its chemical richness. Astronomers used the ALMA facility to detect the first evidence in space of the pre-biotic chemical glycolonitrile (HOCH2CN). ALMA (ESO/NAOJ/NRAO)/L. Calçada (ESO) & NASA/JPL-Caltech/WISE Team

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

    NASA Wise Telescope

    Heterocyclic molecules are those containing atoms of at least two different elements (plus hydrogen) arranged in a ring structure. Nitrogen heterocycles are key components in biological nucleic acids, and in theories of the origins of biogenic molecules they were synthesized from abundant, simpler nitrogen molecules like hydrogen cyanide, HCN. Adenine, one of the four constituent bases of nucleic acids, is thought to have formed from one of the two known two-ring nitrogen heterocycles, glycolonitrile (HOCH2CN). In the cold interstellar medium of space, glycolonitrile could assemble on the surfaces of icy grain surfaces via reactions between formaldehyde (H2CO) and hydrogen cyanide. Astronomers have calculated that glycolonitrile could then be broken apart by ultraviolet light, leaving a variety of simpler nitrogen-bearing molecules, some of which have been detected in molecular clouds in space. Glycolonitrile itself, however, has not been reported leaving a step in the theory of the formation of nucleic acids unconfirmed.

    CfA astronomer Rafael Martin-Domenech and his colleagues used the ALMA telescope facility to search for glycolonitrile in the young, solar-type protostar IRAS16293-2422B. This well-studied object lies about five hundred light-years in the constellation of Ophiuchus. It has a cold outer envelope of gas and dust and a hotter inner region heated by the star extending out to about a hundred astronomical units. Numerous, simpler organic molecules had already been seen in this warm zone. The team searched for the characteristic spectral signature of glycolonitrile in three frequency bands of ALMA, and found thirty-five of its transitions that were unambiguous. They modeled the data to reveal two components at two temperatures, about 24K and 158K, coming correspondingly from material in both the cold outer envelope of the star and its hotter inner zone. Their chemical analysis predicts a smaller abundance of the species than is actually seen, for both the cold and warm components, including under a variety of likely conditions including the cosmic ray ionization rate. The team concludes that some other chemical pathways must be operative, but that this critical chemical has now been measured and the theory is in general on the right track.

    Science paper:
    First Detection of the Pre-biotic Molecule Glycolonitrile (HOCH2CN) in the Interstellar Medium,” S. Zeng, D. Quenard, I. Jimenez-Serra, J Martín-Pintado, V. M. Rivilla, L. Testi, and R. Martın-Domenech
    MNRAS

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 3:07 pm on March 1, 2019 Permalink | Reply
    Tags: An unusual microlensing event. The object MOA-2016-BLG-231, , , , , , CfA, , , Parallax measurement   

    From Harvard-Smithsonian Center for Astrophysics: “Discovering a Brown Dwarf Binary Star with Microlensing” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    March 1, 2019

    Brown dwarfs are stars less massive than the sun and unable to burn hydrogen.

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

    They comprise (at least in mass) a bridge between planets and stars, and astronomers think that they form and evolve in ways different from either planets or stars. Gravitational microlensing is an excellent method for detecting them because it does not depend on their light, which is dim, but rather their mass.

    Gravitational Lensing NASA/ESA

    Gravitational microlensing, S. Liebes, Physical Review B, 133 (1964): 835

    When the path of light from a star passes by a brown dwarf acting as a lens, it is magnified into a distorted image, like an object seen through the stem of a wineglass, allowing the detection and characterization of the lensing object. Thirty-two brown dwarfs have been detected by microlensing so far. Five are in isolation, but most are in binary systems, companions to faint M-dwarf stars. They provide important constraints on brown dwarf formation scenarios.

    The critical parameter of a brown dwarf is its mass, but it is difficult to measure the mass of a lens using microlensing. Using this method, one measures the magnified and distorted stellar image as it changed in time (it varies as the Earth’s vantage point moves), but the technique offers no handle on the distance, and the larger the distance, the larger is the mass needed to generate the same-sized distortion. Recognizing this problem, scientists had predicted that if it ever became possible to observe a microlensing flash from two well-separated vantage points, a parallax measurement (the apparent angular difference between the positions of the star as seen from the two separated sites) would determine the distance of the dark object. The Spitzer Space Telescope circles the Sun in an Earth-trailing orbit, and is currently 1.66 astronomical units away from Earth (one AU is the average distance of the Earth from the Sun).

    NASA/Spitzer Infrared Telescope

    Spitzer is unique in this capability, and it has in fact been used successfully to measure the parallax distance for hundreds of microlensing events, thereby helping to determine the masses of the lenses.

    CfA astronomers Jennifer Yee and In-Gu Shin were members of a large team of microlensing astronomers who used Spitzer together with ground-based telescopes to study an unusual microlensing event. The object, MOA-2016-BLG-231, is located 9400 light-years away in the disk of our galaxy. The shape of its distorted light curve reveals it probably to be a pair of brown dwarfs of masses approximately twenty-one and nine Jupiter-masses, respectively (the smaller one is right at the lower mass limit for being a brown dwarf rather than a giant planet). This is only the fifth brown dwarf binary system discovered in which both objects are brown dwarfs; improved statistics enable astronomers to address the formation mechanisms needed.

    Science paper:
    “Spitzer Microlensing of MOA-2016-BLG-231L: A Counter-rotating Brown Dwarf Binary in the Galactic Disk,” Sun-Ju Chung et al.”
    The Astrophysical Journal

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 9:46 am on February 23, 2019 Permalink | Reply
    Tags: "Simultaneous X-Ray and Infrared Observations of the Galactic Center", , , , CfA,   

    From Harvard-Smithsonian Center for Astrophysics: “Simultaneous X-Ray and Infrared Observations of the Galactic Center” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    1
    A visualization of simulated flaring activity and clouds of material around the supermassive black hole in the galactic center. Astronomers observing these events at X-ray and infrared wavelengths simultaneously report evidence that the X-ray emission often precedes the infrared by ten to twenty minutes, consistent with one class of theoretical models.
    ESO, Gfycat

    The supermassive black hole (SMBH) at the center of our Milky Way galaxy, Sagittarius A*, is by far the closest such object to us, only about 25 thousand light-years away.

    SGR A and SGR A* from Penn State and NASA/Chandra


    Sgr A* from ESO VLT


    SgrA* NASA/Chandra supermassive black hole at the center of the Milky Way


    SGR A* , the supermassive black hole at the center of the Milky Way. NASA’s Chandra X-Ray Observatory

    Although not nearly as active or luminous as other SMBHs, its relative proximity provides astronomers with a unique opportunity to probe what happens close to the “edge” of a black hole. Monitored in the radio since its discovery and more recently in the infrared and the X-ray, Sgr A* appears to be accreting material at a very low rate, only a few hundredths of an Earth-mass per year. Its X-ray emission is persistent, probably resulting from the rapid motions of electrons in the hot accretion flow associated with the black hole. Once a day there are also flares of emission that are highly variable; they appear more often in the infrared than in X-rays. Some submillimeter wavelength flares have also been tentatively linked to IR flares, although their timing seems to be delayed with respect to infrared events. Despite these intensive observational efforts, the physical mechanisms producing flaring around this SMBH are still unknown and are the topic of intense theoretical modeling.

    CfA astronomers Steve Willner, Joe Hora, Giovanni Fazio, and Howard Smith joined their colleagues in undertaking a systematic campaign of simultaneous multiwavelength observations of flaring in SgrA* using the Spitzer and Chandra observatories (the Submillimeter Array was also used in some of the series).

    NASA/Spitzer Infrared Telescope

    NASA/Chandra X-ray Telescope

    CfA Submillimeter Array Mauna Kea, Hawaii, USA, Altitude 4,080 m (13,390 ft)

    In over one hundred hours of data taken over four years (the longest such dataset ever obtained), the team observed four flare events in both X-ray and infrared in which the X-ray event appears to lead the infrared by ten to twenty minutes. The correlation between the observed peaks implies there is some physical connection between them, and the slight timing difference is in agreement with models that describe the flares as coming from magnetically driven particle acceleration and shocks. Exactly simultaneous events can’t be completely ruled out, however, but the results are nevertheless inconsistent with some of the more exotic models that involve the relativistic motion of electrons. If future simultaneous observations planned for the summer of 2019 also see flaring, they can provide new constraints on the time lag and on associated physical models.

    Science paper:
    Simultaneous X-Ray and Infrared Observations of Sagittarius A*’s Variability, The Astrophysical Journal H. Boyce1, D. Haggard, G. Witzel, S. P. Willner, J. Neilsen, J. L. Hora, S. Markoff, G. Ponti, F. Baganoff, E. E. Becklin, G. G. Fazio, P. Lowrance, M. R. Morris, and H. A. Smith.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
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