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  • richardmitnick 7:31 pm on April 20, 2016 Permalink | Reply
    Tags: ALMA, , , Dusty doughnut around massive black hole spied for first time, ,   

    From New Scientist: “Dusty doughnut around massive black hole spied for first time” 

    NewScientist

    New Scientist

    20 April 2016
    Shannon Hall

    1
    A dusty doughnut might look like this. NASA/JPL-Caltech

    It won’t taste very good. We have for the first time imaged one of the doughnuts of dust long thought to encircle some supermassive black holes.

    Astronomers think all galaxies are “active” at some point in their lifetimes, meaning that the central supermassive black hole feeds on a circling disc of gas. Although that disc can be so bright that it outshines the entire galaxy, some seem to be obscured by a doughnut-shaped structure of dust and gas, called a “torus.” Yet because the centres of these active galaxies are so distant, a dusty torus has never been seen – until now.

    Santiago Garcia-Burillo of Spain’s Madrid Observatory and his colleagues used a radio telescope array to image the torus of NGC 1068, a galaxy 50 million light years away. Although it is one of the brightest and nearest active galaxies, its torus still appears tens of thousands of times smaller than the moon.

    The discovery required 35 radio dishes on the Atacama Large Millimeter/submillimeter Array (ALMA) perched in the high desert of the Chilean Andes.

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array

    “It’s an absolutely remarkable observation,” says Jack Gallimore of Bucknell University in Lewisburg, Pennsylvania. “It’s a real testament to how much of a powerhouse ALMA is.”

    It should also shed light on a long-standing problem in astrophysics, namely what causes a galaxy to become active, says Gallimore. Although we know that clouds of gas must fall from the galaxy towards the supermassive black hole, it’s not that simple.

    As the gas falls inward, it spins faster, allowing it to reach a circular velocity like Earth’s orbit around the sun. “A cloud would eventually be spinning so fast that it would just achieve a stable orbit around the black hole,” says Gallimore. “So that prevents it from falling in and feeding the black hole.”

    And yet these supermassive black holes actively accrete gas and dust – enough to grow to millions or billions of times the sun’s mass. So if astronomers can see how gas flows through the torus, they are likely to get a better handle on what sparks the black hole feeding frenzy behind an active galaxy.

    Science paper:
    ALMA resolves the torus of NGC 1068: continuum and molecular line emission

    See the full article here .

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  • richardmitnick 3:13 pm on April 14, 2016 Permalink | Reply
    Tags: ALMA, , , , Stanford astrophysicists help discover hidden dwarf dark galaxy   

    From Stanford: “Stanford astrophysicists help discover hidden dwarf dark galaxy” 

    Stanford University Name
    Stanford University

    April 14, 2016
    Bjorn Carey, Stanford News Service
    (650) 725-1944
    bccarey@stanford.edu

    1
    Composite image of the gravitational lens SDP.81 showing the distorted image of the more distant galaxy (red arcs) and the nearby lensing galaxy (blue center object). By analyzing the distortions in the ring, astronomers have determined that a dark dwarf galaxy (data indicated by white dot near left lower arc segment) is lurking nearly 4 billion light-years away. (Credit: Y. Hezaveh; ALMA)

    The study develops a powerful tool for discovering galaxies that are otherwise too distant to observe, and could lead to advances that improve our understanding of dark matter.

    New analysis of an image taken by the Atacama Large Millimeter/submillimeter Array (ALMA) reveals evidence that a dwarf dark galaxy – a tiny halo companion of a much larger galaxy – is lurking nearly 4 billion light-years away.

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array

    This discovery, led by a Stanford astrophysicist and announced today, paves the way for ALMA to find many more such objects, which could help astronomers address important questions on the nature of dark matter.

    In 2014, as part of ALMA’s Long Baseline Campaign, astronomers studied a variety of astronomical objects to test the telescope’s new high-resolution capabilities. One of these experimental images was that of an Einstein ring, which was produced by a massive foreground galaxy bending the light emitted by another galaxy nearly 12 billion light-years away.

    This phenomenon, called gravitational lensing, was predicted by Einstein’s theory of general relativity, and it offers a powerful tool for studying galaxies that are otherwise too distant to observe. It also sheds light on the properties of the nearby lensing galaxy because of the way its gravity distorts and focuses light from more distant objects.

    In a new paper accepted for publication in the Astrophysical Journal, astrophysicist Yashar Hezaveh at Stanford and his team explain how detailed analysis of this image of a galaxy called SDP.81 uncovered signs of a hidden dwarf dark galaxy in the halo of a the more nearby galaxy.

    “We can find these invisible objects in the same way that you can see rain droplets on a window: You know they are there because they distort the image of the background objects,” explained Hezaveh. In the case of a raindrop, the image distortions are caused by refraction, but here similar distortions are generated by the gravitational influence of dark matter, according to Einstein’s theory of relativity.

    Current theories suggest that dark matter, which makes up 80 percent of the mass of the universe, is made of as-yet-unidentified particles that don’t interact with visible light or other forms of electromagnetic radiation. Dark matter does, however, have appreciable mass, so it can be identified by its gravitational influence.

    For their analysis, the researchers harnessed thousands of computers working in parallel for many weeks, including the National Science Foundation’s most powerful supercomputer, Blue Waters, to search for subtle anomalies that had a consistent and measurable counterpart in each “band” of radio data.

    Blue Waters supercomputer at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign
    Cray Blue Waters supercomputer at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign

    From these combined computations, the researchers were able to piece together an unprecedented understanding of the lensing galaxy’s halo, the diffuse and predominantly star-free region around the galaxy, and discovered a distinctive clump, less than one-thousandth the mass of the Milky Way.

    Because of its relationship to the larger galaxy, its estimated mass and lack of an optical counterpart, the astronomers believe this gravitational anomaly may be caused by an extremely faint, dark-matter dominated satellite of the lensing galaxy. According to theoretical projections, most galaxies should be brimming with similar dwarf galaxies and other companion objects. Detecting them, however, has proven challenging. Even in our own Milky Way, astronomers can identify only about 40 of the thousands of satellite dwarfs that are predicted to be present.

    Computer models of the evolution of the universe indicate that if the number of small dark matter clumps around distant galaxies, like the one detected here, is significantly lower than predictions, this would imply that the dark matter particles have a warm temperature.

    Risa Wechsler, an associate professor of physics at Stanford, and graduate student Yao-Yuan Mao used these compter simulations to show that so far this detection is consistent with the predictions of the cold dark matter theoretical model. More observations are needed, however, to definitively rule out the possibility of a warm temperature for dark matter.

    “This detection is very exciting – it shows that we finally have a tool to find these dwarf satellites efficiently in a way that was not possible before,” said Wechsler. “Now we need to look at other galaxies to hopefully find more of these small dark halos to have a statistically significant test of the cold dark matter predictions.”

    The finding is an exciting demonstration of the power of ALMA, said astrophysicist Roger Blandford, the Luke Blossom Professor in the School of Humanities and Science at Stanford, who was involved in the research. “This discovery proves that ALMA can be used to provide valuable new insights into the physics of dark matter.”

    The other Stanford authors on the paper* include Philip Marshall, Warren Morningstar and Laurence Perreault Levasseur. All Stanford authors are also members of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford.

    *Science paper:
    Detection of lensing substructure using ALMA observations of the dusty galaxy SDP.81

    Science team:
    YASHAR D. HEZAVEH1,12 , NEAL DALAL2,3,4,5 , DANIEL P. MARRONE6 , YAO-YUAN MAO1,7 , WARREN MORNINGSTAR1 , DI WEN2 ,
    ROGER D. BLANDFORD1,7 , JOHN E. CARLSTROM8 , CHRISTOPHER D. FASSNACHT9 , GILBERT P. HOLDER10 , ATHOL KEMBALL2 ,
    PHILIP J. MARSHALL7 , NORMAN MURRAY11,13 , LAURENCE PERREAULT LEVASSEUR1 , JOAQUIN D. VIEIRA2 , RISA H. WECHSLER1,7

    Affiliations:

    1 Kavli Institute for Particle Astrophysics and Cosmology and Department
    of Physics, Stanford University, 452 Lomita Mall, Stanford, CA
    94305-4085, USA
    2 Astronomy Department, University of Illinois at Urbana-Champaign,
    1002 W. Green Street, Urbana IL 61801, USA
    3 School of Natural Sciences, Institute for Advanced Study, 1 Einstein
    Drive, Princeton, NJ 08540, USA
    4 Kavli Institute for the Physics and Mathematics of the Universe, TODIAS,
    The University of Tokyo, Chiba, 277-8583, Japan
    5 Department of Chemistry and Physics, University of Kwa-Zulu Natal,
    University Road, Westville, KZN, South Africa
    6 Steward Observatory, University of Arizona, 933 North Cherry Avenue,
    Tucson, AZ 85721, USA
    7 Kavli Institute for Particle Astrophysics and Cosmology and Department
    of Particle Physics and Astrophysics; SLAC National Accelerator
    Laboratory, Menlo Park, CA 94305, USA
    8 Kavli Institute for Cosmological Physics, University of Chicago, 5640
    South Ellis Avenue, Chicago, IL 60637, USA
    9 Department of Physics, University of California, One Shields Avenue,
    Davis, CA 95616, USA
    10 Department of Physics, McGill University, 3600 Rue University,
    Montreal, Quebec H3A 2T8, Canada
    11 CITA, University of Toronto, 60 St. George St., Toronto ON M5S
    3H8, Canada
    12 Hubble Fellow
    13 Canada Research Chair in Astrophysics

    See the full article here .

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    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

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  • richardmitnick 10:38 am on March 31, 2016 Permalink | Reply
    Tags: ALMA, ALMA's Best Image of a Protoplanetary Disk - TW Hydrae, , , ,   

    From ALMA: “ALMA’s Best Image of a Protoplanetary Disk” 

    ALMA Array

    ALMA

    30 March 2016
    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    ALMA protoplanetary  disk  Sun-like star TW Hydrae.
    ALMA image of the planet-forming disk around the young, Sun-like star TW Hydrae. The inset image (upper right) zooms in on the gap nearest to the star, which is at the same distance as the Earth is from the Sun, suggesting an infant version of our home planet could be emerging from the dust and gas. The additional concentric light and dark features represent other planet-forming regions farther out in the disk. Credit: S. Andrews (Harvard-Smithsonian CfA), ALMA (ESO/NAOJ/NRAO)

    The disks of dust and gas that surround young stars are the formation sites of planets. New images from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal never-before-seen details in the [protoplanetary] disk around a nearby Sun-like star, including a tantalizing gap at the same distance from the star as the Earth is from the Sun. This structure may mean that an infant version of our home planet, or possibly a more massive super-Earth, is beginning to form there.

    The star, TW Hydrae, is a popular target of study for astronomers because of its proximity to Earth (approximately 175 light-years away) and its status as a veritable newborn (about 10 million years old). It also has a face-on orientation as seen from Earth. This affords astronomers a rare, undistorted view of the complete disk.

    “Previous studies with optical and radio telescopes confirm that this star hosts a prominent disk with features that strongly suggest planets are beginning to coalesce,” said Sean Andrews with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper published today in Astrophysical Journal Letters. “The new ALMA images show the disk in unprecedented detail, revealing a series of concentric dusty bright rings and dark gaps, intriguing features that suggest a planet with an Earth-like orbit is forming there.”

    Other pronounced gap features are located 3 billion and 6 billion kilometers from the central stars, similar to the distances from the Sun to Uranus and Pluto in our own Solar System. They too are likely the result of particles that came together to form planets, which then swept their orbits clear of dust and gas and shepherded the remaining material into well-defined bands.

    For the new TW Hydrae observations, astronomers imaged the faint radio emission from millimeter-size dust grains in the disk, revealing details on the order of the distance between the Earth and the Sun (about 150 million kilometers). These detailed observations were made possible with ALMA’s high-resolution, long-baseline configuration. When ALMA’s dishes are at their maximum separation, up to 15 kilometers apart, the telescope is able to resolve finer details. “This is the highest spatial resolution image ever of a protoplanetary disk from ALMA, and that won’t be easily beat going forward,” said Andrews [1].

    “TW Hydrae is quite special. It is the nearest known protoplanetary disk to Earth and it may closely resemble our Solar System when it was only 10 million years old,” said co-author David Wilner, also with the Harvard-Smithsonian Center for Astrophysics.

    Earlier ALMA observations of another system, HL Tau, show that even younger protoplanetary disks – a mere 1 million years old – can display similar signatures of planet formation.

    2
    ALMA image of the protoplanetary disc around HL Tauri – This is the sharpest image ever taken by ALMA

    By studying the older TW Hydrae disk, astronomers hope to better understand the evolution of our own planet and the prospects for similar systems throughout the Galaxy.

    The astronomers’ next phase of research is to investigate how common these kinds of features are in disks around other young stars and how they might change with time or environment.

    Note

    [1] The angular resolution of the images of HL Tauri was similar to these new observations, but as TW Hydrae is much closer to Earth, finer details can be seen.

    This research was presented in a paper “Ringed Substructure and a Gap at 1 AU in the Nearest Protoplanetary Disk”, by S.M. Andrews et al., appearing in the Astrophysical Journal Letters.

    The team is composed of Sean M. Andrews (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), David J. Wilner (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA) , Zhaohuan Zhu (Princeton University, Princeton, New Jersey, USA), Tilman Birnstiel (Max-Planck-Institut für Astronomie, Heidelberg, Germany), John M. Carpenter (Joint ALMA Observatory, Santiago, Chile), Laura M. Pérez (Max-Planck-Institut für Radioastronomie, Bonn, Germany), Xue-Ning Bai (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Karin I. Öberg (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), A. Meredith Hughes (Wesleyan University, Van Vleck Observatory, Middletown, USA), Andrea Isella (Rice University, Houston, Texas, USA) and Luca Ricci (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA).

    Link to science paper.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small

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  • richardmitnick 9:35 am on March 10, 2016 Permalink | Reply
    Tags: ALMA, , , Mysterious Infrared Light from Space Resolved Perfectly   

    From ALMA: “Mysterious Infrared Light from Space Resolved Perfectly” 

    ALMA Array

    ALMA

    10 March 2016
    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Artist’s impression of the Cosmic Infrared Background resolved with ALMA
    Artist’s impression of the Cosmic Infrared Background resolved with ALMA. (Right) This diagram shows that the sum of the emissions from the faint objects detected with ALMA reaches the CIB measured with satellite observations. Credit: NAOJ

    A research team using the Atacama Large Millimeter/submillimeter Array (ALMA) has detected the faintest millimeter-wave source ever observed. By accumulating millimeter-waves from faint objects like this throughout the Universe, the team finally determined that such objects are 100% responsible for the enigmatic infrared background light filling the Universe. By comparing these to optical and infrared images, the team found that 60% of them are faint galaxies, whereas the rest have no corresponding objects in optical/infrared wavelengths and their nature is still unknown.

    The Universe looks dark in the parts between stars and galaxies. However, astronomers have found that there is faint but uniform light, called the “cosmic background emission,” coming from all directions. This background emission consists of three main components; Cosmic Optical Background (COB), Cosmic Microwave Background (CMB), and Cosmic Infrared Background (CIB).

    The origins of the first two have already been revealed. The COB comes from a huge number of stars, and the CMB comes from hot gas just after the Big Bang. However, the origin of the CIB was still to be solved. Various research projects, including past ALMA observations, have been conducted, but they could only explain half of the CIB.

    A research team led by a graduate student, Seiji Fujimoto, and an associate professor, Masami Ouchi, at the University of Tokyo, tackled this mysterious infrared background by examining the ALMA data archive. ALMA is the perfect tool to investigate the source of the CIB thanks to its unprecedented sensitivity and resolution.

    They went through the vast amount of ALMA data taken during about 900 days in total looking for faint objects. They also searched the datasets extensively for lensed sources, where huge gravity has magnified the source making even fainter objects visible [1].

    “The origin of the CIB is a long-standing missing piece in the energy coming from the Universe,” said Seiji Fujimoto, now studying at the Institute of Cosmic Ray Research, the University of Tokyo. “We devoted ourselves to analyzing the gigantic ALMA data in order to find the missing piece.”

    Finally, the team discovered 133 faint objects, including an object five times fainter than any other ever detected. The researchers found that the entire CIB can be explained by summing up the emissions from such objects [2].

    What is the nature of those sources? By comparing the ALMA data with the data taken by the Hubble Space Telescope and the Subaru Telescope, the team found that 60% of them are galaxies which can also be seen in the optical/infrared images.

    NASA Hubble Telescope
    NASA/ESA Hubble

    NAOJ Subaru Telescope
    NAOJ/ Subaru

    Dust in galaxies absorbs optical and infrared light and re-emits the energy in longer millimeter waves which can be detected with ALMA.

    “However, we have no idea what the rest of them are. I speculate that they are galaxies obscured by dust. Considering their darkness, they would be very low-mass galaxies.” Masami Ouchi explained passionately. “This means that such small galaxies contain great amounts of dust. That conflicts with our current understanding: small galaxies should contain small amounts of dust. Our results might indicate the existence of many unexpected objects in the distant Universe. We are eager to unmask these new enigmatic sources with future ALMA observations.”.

    Additional information

    These observational results were published as Fujimoto et al. ALMA Census of Faint 1.2 mm Sources Down to ~ 0.02 mJy: Extragalactic Background Light and Dust-poor, High-z Galaxies in the Astrophysical Journal Supplement, issued in December 28, 2015.

    This research is supported by the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan, and KAKENHI Grant-in-Aid for Scientific Research through the Japan Society for the Promotion of Science (JSPS).

    Notes

    [1] See an explanation and video about gravitational lensing.


    Access the video here .

    [2] ALMA detected a part of the CIB with 1 mm wavelengths. The CIB in millimeter and submillimeter waves does not become weak even if the source is located far away. Therefore this wavelength is suitable for looking through the Universe to the most distant parts.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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  • richardmitnick 11:06 am on March 3, 2016 Permalink | Reply
    Tags: ALMA, , ,   

    From ALMA: “ALMA Spots Baby Star’s Growing Blanket” 

    ALMA Array

    ALMA

    01 March 2016
    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Protoplanetary disc from ALMA
    Typical protoplanetary disc. ALMA

    Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the first direct observations delineating the gas disk around a baby star from the infalling gas envelope. This finding fills an important missing piece in our understanding of the early phases of stellar evolution.

    A team led by Yusuke Aso (a graduate student at the University of Tokyo) and Nagayoshi Ohashi (a professor at the Subaru Telescope, National Astronomical Observatory of Japan) observed the baby star named TMC-1A located 450 light years away from us, in the constellation Taurus (the Bull). TMC-1A is a protostar, a star still in the process of forming. Large amounts of gas still surround TMC-1A.

    Stars form in dense gas clouds. Baby stars grow by taking in the surrounding gas, like a fetus receiving nutrition from the mother’s placenta. In this process, gas cannot flow directly into the star. Instead it first accumulates and forms a disk around the star, and then the disk feeds into the star. However, it is still unknown when in the process of star formation this disk appears and how it evolves. Lack of sensitivity and resolution in radio observations has made it difficult to observe these phenomena.

    “The disks around young stars are the places where planets will be formed,” said Aso, the lead author of the paper that appeared in the Astrophysical Journal. “To understand the formation mechanism of a disk, we need to differentiate the disk from the outer envelope precisely and pinpoint the location of its boundary.”

    Using ALMA, the team directly observed the boundary between the inner rotating disk and the outer infalling envelope with high accuracy for the first time. Since gas from the outer envelope is continuously falling into the disk, it had been difficult to identify the transition region in previous studies. In particular, the tenuous but high speed gas in rotating disks is not easy to see. But ALMA has enough sensitivity to highlight such a component and illustrate the speed and distribution of gas in the disk very precisely. This enabled the team to distinguish the disk from the infalling envelope.

    The team found that the boundary between the disk and envelope is located 90 astronomical units from the central baby star. This distance is three times longer than the orbit of Neptune, the outermost planet in the Solar System. The observed disk obeys Keplerian rotation: the material orbiting closer to the central star revolves faster than material further out.

    The high-sensitivity observations provided other important information about the object. From detailed measurement of the rotation speed, the research team could calculate that the mass of the baby star is 0.68 times the mass of the Sun. The team also determined the gas infall rate to be a millionth of the mass of the Sun per year, with a speed of 1 km per second. Gravity causes gas to fall towards the central baby star, but the measured speed is much less than the free-fall speed. Something must be slowing the gas down. The researchers suspect that a magnetic field around the baby star might be what is slowing the gas.

    “We expect that as the baby star grows, the boundary between the disk and the infall region moves outward,” said Aso. “We are sure that future ALMA observations will reveal such evolution.”

    These observational results were published as Aso et al. ALMA Observations of the Transition from Infall Motion to Keplerian Rotation around the Late-phase Protostar TMC-1A in the Astrophysical Journal.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon
    Stem Education Coalition

    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small

    ESO 50

    NAOJ

     
  • richardmitnick 9:30 am on February 13, 2016 Permalink | Reply
    Tags: ALMA, , , HD 142527 binary system, , Planet Formation around Binary Star,   

    From ALMA: “ALMA Unveils Details of Planet Formation around Binary Star” 

    ALMA Array
    ALMA

    13 February 2016
    Nicolás Lira T.
    Education and Public Outreach Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nlira@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    ALMA Planet Formation around Binary Star
    Artist impression of the HD 142527 binary star system based on data from the Atacama Large Millimeter/submillimeter Array (ALMA). The rendition shows a distinctive arc of dust (red) embedded in the protoplanetary disk. The red arc is free of gas, suggesting the carbon monoxide has “frozen out,” forming a layer of frost on the dust grains in that region. Astronomers speculate this frost provides a boost to planet formation. The two dots in the center represent the two stars in the system. Credit: B. Saxton (NRAO/AUI/NSF)

    Using ALMA, astronomers have taken a new, detailed look at the very early stages of planet formation around a binary star. Embedded in the outer reaches of a double star’s protoplanetary disk, the researchers discovered a striking crescent-shape region of dust that is conspicuously devoid of gas. This result, presented at the AAAS meeting in Washington, D.C., provides fresh insights into the planet-forming potential of a binary system.

    Astronomers struggle to understand how planets form in binary star systems. Early models suggested that the gravitational tug-of-war between two stellar bodies would send young planets into eccentric orbits, possibly ejecting them completely from their home system or sending them crashing into their stars. Observational evidence, however, reveals that planets do indeed form and maintain surprisingly stable orbits around double stars.

    To better understand how such systems form and evolve, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) took a new, detailed look at the planet-forming disk around HD 142527, a binary star about 450 light-years from Earth in a cluster of young stars known as the Scorpius-Centaurus Association.

    The HD 142527 system consists of a main star a little more than twice the mass of our Sun and a smaller companion star only about a third the mass of our Sun. They are separated by approximately one billion miles: a little more than the distance from the Sun to Saturn. Previous ALMA studies of this system revealed surprising details about the structure of the system’s inner and outer disks.

    “This binary system has long been known to harbor a planet-forming corona of dust and gas,” said Andrea Isella, an astronomer at Rice University in Houston, Texas. “The new ALMA images reveal previously unseen details about the physical processes that regulate the formation of planets around this and perhaps many other binary systems.”

    ALMA composite  HD 142527 binary star system
    A composite image of the HD 142527 binary star system from data captured by the Atacama Large Millimeter/submillimeter Array shows a distinctive arc of dust (red) and a ring of carbon monoxide (blue and green). The red arc is free of gas, suggesting the carbon monoxide has “frozen out,” forming a layer of frost on the dust grains in that region. Astronomers speculate this frost provides a boost to planet formation. The two dots in the center represent the two stars in the system. Credit: Andrea Isella/Rice University; B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ)

    Planets form out of the expansive disks of dust and gas that surround young stars. Small dust grains and pockets of gas eventually come together under gravity, forming larger and larger agglomerations and eventually asteroids and planets. The fine points of this process are not well understood, however. By studying a wide range of protoplanetary disks with ALMA, astronomers hope to better understand the conditions that set the stage for planet formation across the Universe.

    ALMA’s new, high-resolution images of HD 142527 show a broad elliptical ring around the double star. The disk begins incredibly far from the central star — about 50 times the Sun-Earth distance. Most of it consists of gases, including two forms of carbon monoxide (13CO and C180), but there is a noticeable dearth of gases within a huge arc of dust that extends nearly a third of the way around the star system.

    This crescent-shaped dust cloud may be the result of gravitational forces unique to binary stars and may also be the key to the formation of planets, Isella speculates. Its lack of free-floating gases is likely the result of them freezing out and forming a thin layer of ice on the dust grains.

    “The temperature is so low that the gas turns into ice and sticks to the grains,” Isella said. “This process is thought to increase the capacity for dust grains to stick together, making it a strong catalyst for the formation of planetesimals, and, down the line, of planets.”

    “We’ve been studying protoplanetary disks for at least 20 years,” Isella said. “There are between a few hundred and a few thousands we can look at again with ALMA to find new and surprising details. That’s the beauty of ALMA. Every time you get new data, it’s like opening a present. You don’t know what’s inside.”

    HD 142527 will be the subject of an upcoming paper led by Rice postdoctoral fellow Yann Boehler, who is working in Isella’s group.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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    • richardmitnick 9:50 am on February 13, 2016 Permalink | Reply

      I have requested the full science team from the contacts listed in the article. If I get the listing, the post will be revised to include it.

      Like

  • richardmitnick 11:24 am on February 3, 2016 Permalink | Reply
    Tags: ALMA, , , IRAM, ,   

    From ALMA: “The Frigid Flying Saucer” 

    ESO ALMA Array
    ALMA

    03 February 2016
    Stephane Guilloteau
    Laboratoire d’Astrophysique de Bordeaux
    Floirac, France
    Email: stephane.guilloteau@u-bordeaux.fr

    Emmanuel di Folco
    Laboratoire d’Astrophysique de Bordeaux
    Floirac, France
    Email: emmanuel.di-folco@u-bordeaux.fr

    Vincent Pietu
    IRAM
    Grenoble, France
    Email: pietu@iram.fr

    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    ALMA Flying Saucer protoplanetary disc around 2MASS J16281370-2431391.
    The Flying Saucer protoplanetary disc around 2MASS J16281370-2431391. This close-up infrared view of the Flying Saucer comes from the NASA/ESA Hubble Space Telescope. Credit: ESO/NASA/ESA

    NASA Hubble Telescope
    NASA/ESA Hubble

    Astronomers have used the ALMA and IRAM telescopes to make the first direct measurement of the temperature of the large dust grains in the outer parts of a planet-forming disc around a young star. By applying a novel technique to observations of an object nicknamed the Flying Saucer they find that the grains are much colder than expected: –266 degrees Celsius. This surprising result suggests that models of these discs may need to be revised.

    The international team, led by Stephane Guilloteau at the Laboratoire d’Astrophysique de Bordeaux, France, measured the temperature of large dust grains around the young star 2MASS J16281370-2431391 in the spectacular Rho Ophiuchi star formation region, about 400 light-years from Earth.

    The Rho Ophiuchi star formation region in the constellation of Ophiuchus.
    The Rho Ophiuchi star formation region in the constellation of Ophiuchus. This wide-field view shows a spectacular region of dark and bright clouds, forming part of a region of star formation in the constellation of Ophiuchus (The Serpent Bearer). This picture was created from images in the Digitized Sky Survey 2. Credit: ESO/Digitized Sky Survey 2

    This star is surrounded by a disc of gas and dust — such discs are called protoplanetary discs as they are the early stages in the creation of planetary systems. This particular disc is seen nearly edge-on, and its appearance in visible light pictures has led to its being nicknamed the Flying Saucer.

    The astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the glow coming from carbon monoxide molecules in the 2MASS J16281370-2431391 disc. They were able to create very sharp images and found something strange — in some cases they saw a negative signal! Normally a negative signal is physically impossible, but in this case there is an explanation, which leads to a surprising conclusion.

    Lead author Stephane Guilloteau takes up the story: “This disc is not observed against a black and empty night sky. Instead it’s seen in silhouette in front of the glow of the Rho Ophiuchi Nebula. This diffuse glow is too extended to be detected by ALMA, but the disc absorbs it. The resulting negative signal means that parts of the disc are colder than the background. The Earth is quite literally in the shadow of the Flying Saucer!”

    The team combined the ALMA measurements of the disc with observations of the background glow made with the IRAM 30-metre telescope in Spain [1].

    IRAM 30m Radio telescope
    IRAM 30-metre telescope

    They derived a disc dust grain temperature of only –266 degrees Celsius (only 7 degrees above absolute zero, or 7 Kelvin) at a distance of about 15 billion kilometers from the central star [2]. This is the first direct measurement of the temperature of large grains (with sizes of about one millimeter) in such objects.

    This temperature is much lower than the –258 to –253 degrees Celsius (15 to 20 Kelvin) that most current models predict. To resolve the discrepancy, the large dust grains must have different properties than those currently assumed, to allow them to cool down to such low temperatures.

    “To work out the impact of this discovery on disc structure, we have to find what plausible dust properties can result in such low temperatures. We have a few ideas — for example the temperature may depend on grain size, with the bigger grains cooler than the smaller ones. But it is too early to be sure,” adds co-author Emmanuel di Folco (Laboratoire d’Astrophysique de Bordeaux).

    If these low dust temperatures are found to be a normal feature of protoplanetary discs this may have many consequences for understanding how they form and evolve.

    For example, different dust properties will affect what happens when these particles collide, and thus their role in providing the seeds for planet formation. Whether the required change in dust properties is significant or not in this respect cannot yet be assessed.

    Low dust temperatures can also have a major impact for the smaller dusty discs that are known to exist. If these discs are composed of mostly larger, but cooler, grains than is currently supposed, this would mean that these compact discs can be arbitrarily massive, so could still form giant planets comparatively close to the central star.

    Further observations are needed, but it seems that the cooler dust found by ALMA may have significant consequences for the understanding of protoplanetary discs.

    Notes

    [1] The IRAM measurements were needed as ALMA itself was not sensitive to the extended signal from the background.

    [2] This corresponds to one hundred times the distance from the Earth to the Sun. This region is now occupied by the Kuiper Belt within the Solar System.

    Kuiper Belt
    Known objects in the Kuiper belt beyond the orbit of Neptune. (Scale in AU; epoch as of January 2015.)

    Additional information

    This research was presented in a paper entitled The shadow of the Flying Saucer: A very low temperature for large dust grains, by S. Guilloteau et al., published in Astronomy & Astrophysics Letters.

    The team is composed of S. Guilloteau (University of Bordeaux/CNRS, Floirac, France), V. Piétu (IRAM, Saint Martin d’Hères, France), E. Chapillon (University of Bordeaux/CNRS; IRAM), E. Di Folco (University of Bordeaux/CNRS), A. Dutrey (University of Bordeaux/CNRS), T.Henning (Max Planck Institute für Astronomie, Heidelberg, Germany [MPIA]), D.Semenov (MPIA), T.Birnstiel (MPIA) and N. Grosso (Observatoire Astronomique de Strasbourg, Strasbourg, France).

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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  • richardmitnick 11:45 am on January 27, 2016 Permalink | Reply
    Tags: ALMA, , , , ,   

    From ALMA: “ALMA confirms predictions on the interaction between protoplanetary disks and planets” 

    ESO ALMA Array
    ALMA

    27 January 2016
    Héctor Cánovas
    Universidad de Valparaíso Valparaíso, Chile
    Tel: +56 032 – 299 5555
    Tel: +56 02 84144232
    E-mail: hector.canovas@uv.cl

    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    E-mail: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 202 236 6324
    E-mail: cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    E-mail: rhook@eso.org

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory

    Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    Protoplanetary disc from ALMA
    Image taken by ALMA of the dust ring that surrounds the young star Sz 91. This ring is primarily made up of mm-sized dust particles. The interaction between several recently formed planets and the protoplanetary disk that still surrounds the star probably generate the dust ring observed by ALMA.

    New observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) of the disk that surrounds a young star, less massive than the Sun, confirm theories about the interaction between recently formed planets and disks. A team of astronomers led by Héctor Cánovas from Universidad de Valparaíso and the Millennium ALMA Disk Nucleus (MAD) observed the dust ring possibly sculpted by planets in formation around the star Sz 91, at a distance roughly 650 light years from Earth.

    The results obtained show the first disk around a star that is less massive than ours – it has only half of the mass of our Sun – which simultaneously presents a migration of dust particles from the outermost zones and evident signs of interaction between young planets with the disk in the innermost zone.

    Planets are born in dust and gas disks that surround young stars and feed them with matter, leaving a “footprint” of this interaction in the structure of the disk. The theoretical models that study this interaction predict that the planets carve the protoplanetary disk, creating a “hole” in the innermost part of the disk, and preventing mm-sized dust particles (like grains of sand on a beach) from continuing their journey towards the central star. At the same time, dust particles in the outermost parts of the disk (the farthest from the star) are attracted by the gravitational force of the star.

    The combination of both effects should create dust structures in the form of a ring in disks that host recently formed giant planets on the inside.

    “The sharp image from ALMA shows a ring around the young star. And it is a surprisingly large ring, over three times the size of Neptune’s orbit (a radius of approximately 110 astronomical units (AU)” explains Héctor Cánovas.

    The image from ALMA only shows the ring, as the radio telescope detects the cold dust particles that make it up, and not the planets and the star, as these are primarily made up of hot gas.

    “Based on the current paradigm of planet-disk interactions, only giant planets orbiting the innermost parts of the disk can explain the presence of a ring with such a large radius,” indicates Antonio Hales, ALMA astronomer and member of the research team.

    The accumulation of dust particles in a narrow annular structure, as is the case with Sz91, can favor the formation of more planets, because the high density of dust particles in the ring would provide the ideal conditions for the dust particles to agglutinate and grow in size until they form small planetary nuclei.

    “The results of this investigation show that Sz91 is a highly important protoplanetary disk for the study of planetary formation, planet-disk interactions, and the evolution of these disks around stars of lower mass, as Sz91 shows evidence of all these processes simultaneously,” concludes Matthias Schreiber, coauthor of the study.

    Additional information

    This investigation was presented in an article entitled A ring-like concentration of mm-sized particles in Sz 91, written by Héctor Cánovas and collaborators, which will soon be published in the specialized journal Monthly Notices of the Royal Astronomical Society (MNRAS).

    The research team is made up of Héctor Cánovas, Claudio Cáceres, Matthias Schreiber, Adam Hardy (all from Universidad de Valparaíso and from the Millennium ALMA Disk Nucleus (MAD), Chile), Lucas Cieza (Universidad Diego Portales and MAD, Chile), Francois Ménard (Universidad de Chile) and Antonio Hales (JAO-ALMA, Chile).

    Link

    A ring-like concentration of mm-sized particles in Sz 91

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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  • richardmitnick 10:34 am on January 15, 2016 Permalink | Reply
    Tags: ALMA, , , Chaotic Turbulence Roiling 'Most Luminous Galaxy' in the Universe,   

    From ALMA: “Chaotic Turbulence Roiling ‘Most Luminous Galaxy’ in the Universe” 

    ESO ALMA Array
    ALMA

    15 January 2016
    Tanio Díaz Santos
    Núcleo de Astronomía, Facultad de Ingeniería
    Universidad Diego Portales, Santiago, Chile
    Tel: +56 2 2213 0480
    Email: tanio.diaz@mail.udp.cl

    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    Masaaki Hiramatsu

    Education and Public Outreach Officer, NAOJ Chile
    Observatory
Tokyo, Japan

    Tel: +81 422 34 3630

    E-mail: hiramatsu.masaaki@nao.ac.jp

    Temp 1
    Artist impression of W2246-0526, a single galaxy glowing in infrared light as intensely as approximately 350 trillion suns. It is so violently turbulent that it may eventually jettison its entire supply of star-forming gas, according to new observations with ALMA. Credit: NRAO/AUI/NSF; Dana Berry / SkyWorks; ALMA (ESO/NAOJ/NRAO).

    The most luminous galaxy in the Universe –a so-called obscured quasar 12.4 billion light-years away – is so violently turbulent that it may eventually jettison its entire supply of star-forming gas, according to new observations with the Atacama Large Millimeter/submillimeter Array (ALMA).

    A team of researchers used ALMA to trace, for the first time, the actual motion of the galaxy’s interstellar medium – the gas and dust between the stars. What they found, according to Tanio Díaz-Santos of the Universidad Diego Portales in Santiago, Chile, and lead author of this study, is a galaxy “so chaotic that it is ripping itself apart.”

    Previous studies with NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft reveal that the galaxy, dubbed W2246-0526, is glowing in infrared light as intensely as approximately 350 trillion suns.

    NASA Wise Telescope
    NASA/WISE

    Evidence strongly suggests that this galaxy is actually an obscured quasar, a very distant galaxy [whi h] contains a voraciously feeding supermassive black hole at its center that is completely obscured behind a thick blanket of dust.

    This galaxy’s startling brightness is powered by a tiny, yet incredibly energetic disk of gas that is being superheated as it spirals in on the supermassive black hole. The light from this blazingly bright accretion disk is then absorbed by the surrounding dust, which re-emits the energy as infrared light.

    “These properties make this object a beast in the infrared,” said Roberto Assef, an astronomer with the Universidad Diego Portales and leader of the ALMA observing team. “The powerful infrared energy emitted by the dust then has a direct and violent impact on the entire galaxy, producing extreme turbulence throughout the interstellar medium.”

    The astronomers compare this turbulent action to a pot of boiling water. If these conditions continue, they say, the galaxy’s intense infrared radiation would boil away all of its interstellar gas.

    This galaxy belongs to a very unusual type of quasar known as Hot, Dust-Obscured Galaxies or Hot DOGs These objects are very rare; only 1 out of every 3,000 quasars observed by WISE belong to this class.

    The research team used ALMA to precisely map the motion of ionized carbon atoms throughout the entire galaxy. These atoms, which are tracers for interstellar gas, naturally emit infrared light, which becomes shifted to millimeter wavelengths as it travels the vast cosmic distances to Earth due to the expansion of the Universe.

    “Large amounts of ionized carbon were found in an extremely turbulent dynamic state throughout the galaxy,” Díaz-Santos describes. The data reveal that this interstellar material is careening anywhere from 500 to 600 kilometers per second across the entire galaxy.

    The astronomers believe that this turbulence is primarily due to the fact that the region around the black hole is at least 100 times more luminous than the rest of the host galaxy combined; in other quasars, the proportion is much more modest. This intense yet localized radiation exerts tremendous pressure on the entire galaxy, to potentially devastating effect.

    “We suspected that this galaxy was in a transformative stage of its life because of the enormous amount of infrared energy discovered with WISE,” said Peter Eisenhardt with NASA’s Jet Propulsion Laboratory in Pasadena, California, and scientific leader of the WISE mission. “Now ALMA has shown us that the raging furnace in this galaxy is making the pot boil over.”

    Current models of galactic dynamics combined with the ALMA data indicate that this galaxy is unstable and its interstellar gas is being blown away in all directions. This means that the galaxy’s Hot DOG days are numbered as it matures into a more traditional unobscured quasar.

    “If this pattern continues, it is possible that in the future W2246 ends up shedding a large part of the gas and dust it contains,” concludes Manuel Aravena also from the Universidad Diego Portales, and co-author of the study. “Only ALMA, with its unparalleled resolution, can allow us to see this object in high definition and fathom such an important episode in the life of this galaxy.”

    This article, The Strikingly Uniform, Highly Turbulent Interstellar Medium of The Most Luminous Galaxy in the Universe, will be published in the Astrophysical Journal Letters.

    From ESO article:

    This research was presented in a paper “The Strikingly Uniform, Highly Turbulent Interstellar Medium of The Most Luminous Galaxy in the Universe”, by T. Díaz-Santos et al., and will be published in the journal Astrophysical Journal Letters.

    The team is composed of T. Díaz-Santos (Universidad Diego Portales, Santiago, Chile), R. J. Assef (Universidad Diego Portales, Santiago, Chile), A. W. Blain (University of Leicester, UK) , C.-W. Tsai (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA) , M. Aravena (Universidad Diego Portales, Santiago, Chile), P. Eisenhardt (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA), J. Wu (University of California Los Angeles, California, USA), D. Stern (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA) and C. Bridge (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA).

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon
    Stem Education Coalition

    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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  • richardmitnick 12:51 pm on December 18, 2015 Permalink | Reply
    Tags: ALMA, ALMA Trilateral Agreement, , , ,   

    From ALMA: “ALMA Trilateral Agreement Signing Ceremony” 

    ESO ALMA Array
    ALMA

    18 December 2015
    Nicolás Lira T.
    Education and Public Outreach Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nlira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory Tokyo, Japan
    Tel: +81 422 34 3630
    E-mail: hiramatsu.masaaki@nao.ac.jp

    Charles E. Blue
    Public Information Officer
    National Radio Astronomy Observatory
    Charlottesville, Virginia, USA
    Tel: +1 434 296 0314
    Cell: +1 434.242.9559
    E-mail: cblue@nrao.edu

    Richard Hook
    Public Information Officer, ESO
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    1
    The ALMA Trilateral Agreement was signed by Tim de Zeeuw, the Director General of ESO, Katsuhiko Sato, the President of NINS, and F. Fleming Crim, the Assistant Director of NSF on behalf of France A. Córdova, the Director of NSF. Credit: ALMA (ESO/NAOJ/NRAO)

    On December 15, 2015, the National Institutes of Natural Sciences of Japan (NINS), the European Southern Observatory (ESO), and the National Science Foundation (NSF) signed an agreement concerning the operations of ALMA. The new agreement signed in Tokyo provides the framework for the long-lasting operations of ALMA over the next 20 years.

    “As NINS, we have responsibility to fulfill our commitment to the operations of ALMA as a party of this agreement.”, told Katsuhiko Sato, the president of NINS, in his speech in the signing ceremony. “We hope our contributions could lead to significant scientific results with ALMA. And, our contributions will be beneficial to global advances in understanding the physics of the Universe as stated in the agreement.”

    The first resolution for ALMA was concluded at the ALMA Coordination Committee meeting held in Tokyo in 2001. This was the formal start of the Atacama Large Millimeter Array as an international collaboration project between Japan, US, and Europe. The ALMA construction budgets were approved in US and Europe in 2001 and 2002 respectively. While the budget in Japan was yet to be approved at that time, NSF and ESO signed a bilateral agreement in 2003 and started construction of ALMA. Japan finally secured the budget in 2004 and joined the project by signing an agreement for the construction of the enhanced ALMA. Japan brought an enhanced capability of submillimeter observations and “Atacama Large Millimeter/submillimeter Array” was realized.

    “Big telescopes demand big partnerships,” said Dr. Córdova, the director of NSF in her video message for the ceremony. “Today’s new trilateral agreement is evidence of that commitment. We mark a point when ALMA’s future is made brighter because of our three organizations’ zeal to learn more about the Universe where we all live.”

    “The ALMA conference which took place in Tokyo last year demonstrated that the dream of a truly transformational facility for astronomy has become a reality,” told Tim de Zeeuw, the Director General of ESO. “I am certain that the power and efficiency of the facility will continue to increase in the years to come. It is a testimony to the visionary and motivated individuals who laid the groundwork more than three decades ago, and turned it onto a reality.”.

    The construction and development of ALMA and initial observations have been carried out based on the agreement signed in 2004. With an inauguration ceremony held in 2013, ALMA formally became a fully-fledged observatory. A new agreement focusing on science operations have been prepared since then, and signed this time by Sato, de Zeeuw and F. Fleming Crim, the assistant director of NSF on behalf of France A. Córdova.

    The new agreement signals the continuing trust and cooperation between ESO, NSF and NINS as ALMA makes the transition from construction into full science operations that are expected to last over three decades.

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small

    ESO 50

    NAOJ

     
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