Tagged: CfA Toggle Comment Threads | Keyboard Shortcuts

  • 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.

     
  • richardmitnick 5:07 pm on February 15, 2019 Permalink | Reply
    Tags: , , , CfA, , Energetic Particles Can Bombard Exoplanets, TRAPPIST-1 is a system of seven Earth-sized worlds orbiting an ultra-cool dwarf star about 120 light-years away   

    From Harvard-Smithsonian Center for Astrophysics: “Energetic Particles Can Bombard Exoplanets” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    February 15, 2019

    TRAPPIST-1 is a system of seven Earth-sized worlds orbiting an ultra-cool dwarf star about 120 light-years away.

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

    The star, and hence its system of planets, is thought to be between five-to-ten billion years old, up to twice as old as our own solar system. For scientists seeking evidence for life elsewhere, the advanced age provides more time for chemistry and evolution to operate than the Earth had. On the other hand, the planets are all close to the star (in fact they are probably tidally locked to the star with one side always facing it), and consequently would have soaked up billions more year’s-worth of high energy radiation from the star’s winds, adversely affecting any atmospheres they host.

    In a new paper in The Astrophysical Journal, CfA astronomers Federico Fraschetti, Jeremy Drake, Julian Alvardo-Gomez, Sofia Moschou, and Cecilia Garraffo and a colleague carry out theoretical simulations of the effects of high-energy protons from a stellar wind on nearby exoplanets. These particles are produced by stellar flares or by shock waves driven by magnetic events in the stellar corona. Measurements of solar eruptive events provide the scientists with a basis for their simulations.

    The astronomers calculate the first realistic simulation of the propagation of energetic particles through the turbulent magnetic field environment of an M dwarf star and its wind, and they tailored the details to the TRAPPIST-1 system. They find that particles are trapped within the star’s magnetic field and are directed into two polar streams focused onto the planets’ orbital plane – independent of many of the details. The scientists conclude that the innermost putative habitable planet in the system, TRAPPIST-1e, is bombarded by a proton flux up to a million times larger than that experienced by the present-day Earth. Nevertheless, there are many variables at play, for example the angle between the magnetic field and the rotation axis of the star, and consequently a large uncertainty remains in how these effects actually are manifest in individual situations.

    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 5:41 pm on January 25, 2019 Permalink | Reply
    Tags: A Primordial Star Forming Galaxy, , , , CfA, , Luminous galaxy G09_83808   

    From Harvard-Smithsonian Center for Astrophysics: “A Primordial Star Forming Galaxy” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    January 25, 2019

    1
    A Hubble image of an ultraluminous infrared galaxy in the relatively nearby universe. Astronomers studying ultraluminous galaxies in the remote, early universe have spotted one dating from the epoch only one billion years after the big bang and found, surprisingly, that is it similar to modern ones like this. NASA/ESA Hubble

    Galaxies with extremely high rates of star formation (from hundreds to thousands of solar-masses worth of stars per year) are rare. Our Milky Way, for example, makes only about one star a year. The process of star formation heats up dust to emit in the infrared, and extreme starburst galaxies that make this many per year shine so brightly they can be spotted at cosmological distances. When gravitational lensing by a fortuitously intervening galaxy or cluster of galaxies magnifies the signal, even farther away and cosmically earlier galaxies can be detected.

    Gravitational Lensing NASA/ESA

    To date only a handful of these extreme starburst galaxies have been confirmed from the universe’s first billion years of existence. Although still a small sample, they offer important insights into how stars were made at primordial times when most chemical elements were less abundant. They also help astronomers understand star formation in cases where the physical processes are so dramatic when compared to the process in our galaxy.

    Far infrared and submillimeter sky surveys identified the first extreme galaxies from the emission of dust heated by their star formation activity. The rate of star formation is inferred from the luminosity of the galaxy, and this is calculated from the observed brightness and distance. As usual in astronomy, the distance parameter is key but difficult to measure. For these remote monsters it is generally obtained from the redshift of some strong lines emitted by the galaxy in the far infrared or submillimeter, typically from carbon monoxide (an abundant molecule) and/or from singly ionized atomic carbon.

    CfA astronomer David Wilner was a member of a large team of astronomers that used the Large Millimeter Telescope Alfonso Serrano (LMT) in Mexico to followup the luminous galaxy G09_83808 that was first spotted in Herschel Space Observatory survey images;

    The University of Massachusetts Amherst and Mexico’s Instituto Nacional de Astrofísica, Óptica y Electrónica
    Large Millimeter Telescope Alfonso Serrano, Mexico, at an altitude of 4850 meters on top of the Sierra Negra

    ESA/Herschel spacecraft active from 2009 to 2013

    they also observed it with the ALMA facility to probe its spatial extent and with the Submillimeter Array to measure its carbon line.

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

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

    The spectral lines date the galaxy to about one billion years after the big bang, making it one of the first discovered whose unambiguous distance was that far away. Calculations of its star formation rate based on the luminosity corrected for effects of extinction and lensing find it to be about 380 solar-masses per year, comparable in fact to some of the ultra-luminous galaxies in our own cosmic era. This result implies that despite about twelve billion years of cosmic history, this galaxy is making stars in the same way as do extreme galaxies today. The object also has a relatively weak atomic carbon line, a characteristic also found (but still not well understood) to apply in luminous local systems. The new result also confirms that the early universe had luminous galaxies with physical processes that, although not well understood, appear to mirror closely local extreme cases.

    Science Paper:
    “A Dusty Star-Forming Galaxy at z = 6 Revealed by Strong Gravitational Lensing,” Jorge A. Zavala et al.
    Nature Astronomy

    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 2:25 pm on January 22, 2019 Permalink | Reply
    Tags: , , , , CfA, , Sagittarius A*   

    From Harvard-Smithsonian Center for Astrophysics: “Lifting the Veil on the Black Hole at the Heart of Our Galaxy” 

    Harvard Smithsonian Center for Astrophysics


    From Harvard-Smithsonian Center for Astrophysics

    January 22, 2019

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

    1

    A black hole four million times as massive as our Sun lurks at the center of the Milky Way. This black hole, called Sagittarius A* (Sgr A*), swallows nearby material that glows brightly as it approaches the event horizon.

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

    This galactic furnace is key to understanding black holes, but our view of it is obscured by lumpy clouds of electrons throughout the Galaxy. These clouds stretch, blur, and crinkle the image of Sgr A*, making it appear as though the black hole is blocked by an enormous sheet of frosted glass.

    Now, a team of astronomers, led by Radboud University PhD student Sara Issaoun, have finally been able to see through these clouds and to study what makes the black hole glow. Issaoun completed this work while participating in the Predoctoral Program at the Smithsonian Astrophysical Observatory in Cambridge, MA.

    “The source of the radiation from Sgr A* has been debated for decades,” says Michael Johnson of the Center for Astrophysics | Harvard and Smithsonian (CfA). “Some models predict that the radiation comes from the disk of material being swallowed by the black hole, while others attribute it to a jet of material shooting away from the black hole. Without a sharper view of the black hole, we can’t exclude either possibility.”

    The team used the technique of Very Long Baseline Interferometry (VLBI), which combines many telescopes to form a virtual telescope the size of the Earth. The decisive advance was equipping the powerful ALMA array of telescopes in northern Chile with a new phasing system. This allowed it to join the GMVA, a global network of twelve other telescopes in North America and Europe.

    GMVA The Global VLBI Array

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

    “ALMA itself is a collection of more than 50 radio dishes. The magic of the new ALMA Phasing System is to allow all these dishes to function as a single telescope, which has the sensitivity of a single dish more than 75 meters across. That sensitivity, and its location high in the Andes mountains, makes it perfect for this Sgr A* study,” says Shep Doeleman of the CfA, who was Principal Investigator of the ALMA Phasing Project.

    “The breakthrough in image quality came from two factors,” explains Lindy Blackburn, a radio astronomer at the CfA. “By observing at high frequencies, the image corruption from interstellar material was less significant, and by adding ALMA, we doubled the resolving power of our instrument.”

    The new images show that the radiation from Sgr A* has a symmetrical morphology and is smaller than expected – it spans a mere 300 millionth of a degree. “This may indicate that the radio emission is produced in a disk of infalling gas rather than by a radio jet,” explains Issaoun, who tested computer simulations against the images. “However, that would make Sgr A* an exception compared to other radio-emitting black holes. The alternative could be that the radio jet is pointing almost directly at us.”

    Issaoun’s supervisor Heino Falcke, Professor of Radio Astronomy at Radboud University, was surprised by this result. Last year, Falcke would have considered this new jet model implausible, but recently another set of researchers came to a similar conclusion using ESO’s Very Large Telescope Interferometer of optical telescopes and an independent technique. “Maybe this is true after all,” concludes Falcke, “and we are looking at this beast from a very special vantage point.”

    To learn more will require pushing these telescopes to even higher frequencies. “The first observations of Sgr A* at 86 GHz date from 26 years ago, with only a handful of telescopes. Over the years, the quality of the data has improved steadily as more telescopes join,” says J. Anton Zensus, director of the Max Planck Institute for Radio Astronomy.

    Michael Johnson is optimistic. “If ALMA has the same success in joining the Event Horizon Telescope at even higher frequencies, then these new results show that interstellar scattering will not stop us from peering all the way down to the event horizon of the black hole.”

    The results were published in The Astrophysical Journal.

    See the full article here .

    See also 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.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: