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  • richardmitnick 7:55 am on March 17, 2017 Permalink | Reply
    Tags: , ALMA Confirms ability to see a “Cosmic Hole, , , , , Millimeter/submillimeter astronomy, , Sunyaev-Zel'dovich effect (SZ effect)   

    From ALMA: “ALMA Confirms ability to see a “Cosmic Hole” 

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

    17 March 2017
    Nicolás Lira T.
    Press Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nicolas.lira@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

    1
    The image shows the measurement of the SZ effect in the galaxy cluster RX J1347.5-1145 taken with ALMA (blue). The background image was taken by the Hubble Space Telescope. A “hole” caused by the SZ effect is seen in the ALMA observations. Credit: ALMA (ESO/NAOJ/NRAO), Kitayama et al., NASA/ESA Hubble Space Telescope.

    Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) successfully imaged a radio “hole” around a galaxy cluster 4.8 billion light-years away from the Earth. This is the highest resolution image ever taken of such a hole caused by the Sunyaev-Zel’dovich effect (SZ effect). The image proves ALMA’s high capability to investigate the distribution and temperature of gas around galaxy clusters through the SZ effect.

    A research team led by Tetsu Kitayama, a professor at Toho University, Japan, used ALMA to investigate the hot gas in a galaxy cluster. The hot gas is an essential component to understand the nature and evolution of galaxy clusters. Even though the hot gas does not emit radio waves detectable with ALMA, the gas scatters the radio waves of the Cosmic Microwave Background and makes a “hole” around the galaxy cluster. This is the Sunyaev-Zel’dovich effect[1].

    The team observed the galaxy cluster RX J1347.5-1145 known among astronomers for its strong SZ effect and which has been observed many times with radio telescopes.

    2
    ROSAT Lensing Cluster RX J1347-1145. Max-Planck-Institut für extraterrestrische Physik

    For example, the Nobeyama 45-m Radio Telescope, operated by the National Astronomical Observatory of Japan, has revealed an uneven distribution of the hot gas in this galaxy cluster, which was not seen in X-ray observations.

    .
    Nobeyama Radio Telescope, located in the Nobeyama highlands in Nagano, Japan

    To better understand the unevenness, astronomers need higher resolution observations. But relatively smooth and widely-distributed objects, such as the hot gas in galaxy clusters, are difficult to image with high-resolution radio interferometers.

    To overcome this difficulty, ALMA utilized the Atacama Compact Array, also known as the Morita Array, the major Japanese contribution to the project.


    Atacama Compact Array alma.mtk.nao.ac.jp

    The Morita Array’s smaller diameter antennas and the close-packed antenna configuration provide a wider field of view. By using the data from the Morita Array, astronomers can precisely measure the radio waves from objects subtending a large angle on the sky.

    3
    This cluster of galaxies, RX J1347.5–1145, was observed by the NASA/ESA Hubble Space Telescope as part of the Cluster Lensing and Supernova survey with Hubble (CLASH). The cluster is one of most massive known galaxy clusters in the Universe. Credit: ESA/Hubble, NASA.


    NASA/ESA Hubble Telescope

    With ALMA, the team obtained an SZ effect image of RX J1347.5-1145, with twice the resolution and ten times better sensitivity than previous observations. This is the first image of the SZ effect with ALMA. The ALMA SZ image is consistent with the previous observations and better illustrates the pressure distribution of hot gas. It proves that ALMA is highly capable of observing the SZ effect and clearly shows that a gigantic collision is ongoing in this galaxy cluster.

    “It was nearly 50 years ago that the SZ effect was proposed for the first time,” explains Kitayama. “The effect is pretty weak, and it has been tough to image the effect with high resolution. Thanks to ALMA, this time we made a long-awaited breakthrough to pave a new path to probe the cosmic evolution.”

    Notes

    “Cosmic Microwave Background (CMB)” radio waves come from every direction. When CMB radio waves pass through the hot gas in a galaxy cluster, the radio waves interact with high-energy electrons in the hot gas and gain energy. As a result, the CMB radio waves shift to higher energy. Observing from the Earth, the CMB in the original energy range has less intensity near the galaxy cluster. This is called the “Sunyaev-Zel’dovich effect,” first proposed by Rashid Sunyaev and Yakov Zel’dovich in 1970.

    Additional information

    These observation results were published as Kitayama et al. The Sunyaev-Zel’dovich effect at 5″: RX J1347.5-1145 imaged by ALMA in the Publications of the Astronomical Society of Japan in October 2016.

    The research team members are: Tetsu Kitayama (Toho University), Shutaro Ueda (Japan Aerospace Exploration Agency), Shigehisa Takakuwa (Kagoshima University / Academia Sinica Institute of Astronomy and Astrophysics), Takahiro Tsutsumi (U. S. National Radio Astronomy Observatory), Eiichiro Komatsu (Max-Planck Institute for Astrophysics / Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo), Takuya Akahori (Kagoshima University), Daisuke Iono (National Astronomical Observatory of Japan / SOKENDAI), Takuma Izumi (The University of Tokyo), Ryohei Kawabe (National Astronomical Observatory of Japan / SOKENDAI / The University of Tokyo), Kotaro Kohno (The University of Tokyo), Hiroshi Matsuo (National Astronomical Observatory of Japan / SOKENDAI), Naomi Ota (Nara Women’s University), Yasushi Suto (The University of Tokyo), Motokazu Takizawa (Yamagata University), and Kohji Yoshikawa (University of Tsukuba).

    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 March 15, 2017 Permalink | Reply
    Tags: , , , Cat's Paw Nebula (also known as NGC 6334), , Millimeter/submillimeter astronomy, Protostar Blazes Bright, , Reshaping Its Stellar Nursery   

    From ALMA: “Protostar Blazes Bright, Reshaping Its Stellar Nursery” 

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

    15 March 2017
    Nicolás Lira T.
    Press Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nicolas.lira@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

    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

    1
    ALMA image of the glowing dust inside NGC 6334I, a protocluster containing an infant star that is undergoing an intense growth spurt, likely triggered by an avalanche of gas falling onto its surface. ALMA (ESO/NAOJ/NRAO); C. Brogan, B. Saxton (NRAO/AUI/NSF).

    A massive protostar, deeply nestled in its dust-filled stellar nursery, recently roared to life, shining nearly 100 times brighter than before. This outburst, apparently triggered by an avalanche of star-forming gas crashing onto the surface of the star, supports the theory that young stars can undergo intense growth spurts that reshape their surroundings.

    Astronomers made this discovery by comparing new observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile with earlier observations from the Submillimeter Array (SMA) in Hawaii.


    CfA Submillimeter Array Mauna Kea, Hawaii, USA

    “We were amazingly fortunate to detect this spectacular transformation of a young, massive star,” said Todd Hunter, an astronomer at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, USA, and lead author on a paper published in the Astrophysical Journal Letters. “By studying a dense star-forming cloud with both ALMA and the SMA, we could see that something dramatic had taken place, completely changing a stellar nursery over a surprisingly short period of time.”

    In 2008, before the era of ALMA, Hunter and his colleagues used the SMA to observe a small but active portion of the Cat’s Paw Nebula (also known as NGC 6334), a star-forming complex located about 5,500 light-years from Earth in the direction of the southern constellation Scorpius. This nebula is similar in many respects to its northern cousin, the Orion Nebula, which is also brimming with young stars, star clusters, and dense cores of gas that are on the verge of becoming stars. The Cat’s Paw Nebula, however, is forming stars at a faster rate.

    2
    Inside the Cats’s Paw Nebula as seen in an infrared image from NASA’s Spitzer Space Telescope (left), ALMA discovered that an infant star is undergoing an intense growth spurt, shining nearly 100 brighter than before and reshaping its stellar nursery (right). Credit: ALMA (ESO/NAOJ/NRAO), T. Hunter; C. Brogan, B. Saxton (NRAO/AUI/NSF); NASA Spitzer.


    NASA/Spitzer

    The initial SMA observations of this portion of the nebula, dubbed NGC 6334I, revealed what appeared to be a typical protocluster: a dense cloud of dust and gas harboring several still-growing stars.

    Young stars form in these tightly packed regions when pockets of gas become so dense that they begin to collapse under their own gravity. Over time, disks of dust and gas form around these nascent stars and funnel material onto their surfaces helping them grow.

    This process, however, may not be entirely slow and steady. Astronomers now believe that young stars can also experience spectacular growth spurts, periods when they rapidly acquire mass by gorging on star-forming gas.

    The new ALMA observations of this region, taken in 2015 and 2016, reveal that dramatic changes occurred toward a portion of the protocluster called NGC 6334I-MM1 in the years since the original SMA observations. This region is now about four times brighter at millimeter wavelengths, meaning that the central protostar is nearly 100 times more luminous than before.

    The astronomers speculate that leading up to this outburst, an uncommonly large clump of material was drawn into the star’s accretion disk, creating a logjam of dust and gas. Once enough material accumulated, the logjam burst, releasing an avalanche of gas onto the growing star.

    4
    Comparing observations by two different millimeter-wavelength telescopes, ALMA and the SMA, astronomers noted a massive outburst in a star-forming cloud. Because the ALMA images are more sensitive and show finer detail, it was possible to use them to simulate what the SMA could have seen in 2015 and 2016. By subtracting the earlier SMA images from the simulated images, astronomers could see that a significant change had taken place in MM1 while the other three millimeter sources (MM2, MM3, and MM4) are unchanged. ALMA (ESO/NAOJ/NRAO); SMA, Harvard/Smithsonian CfA

    This extreme accretion event greatly increased the star’s luminosity, heating its surrounding dust. It’s this hot, glowing dust that the astronomers observed with ALMA. Though similar events have been observed in infrared light, this is the first time that such an event has been identified at millimeter wavelengths.

    To ensure that the observed changes were not the result of differences in the telescopes or simply a data-processing error, Hunter and his colleagues used the ALMA data as a model to accurately simulate what the SMA — with its more modest capabilities — would have seen if it conducted similar operations in 2015 and 2016. By digitally subtracting the actual 2008 SMA images from the simulated images, the astronomers confirmed that there was indeed a significant and consistent change to one member of the protocluster.

    “Once we made sure we were comparing the two sets of observations on an even playing field, we knew that we were witnessing a very special time in the growth of a star,” said Crystal Brogan, also with the NRAO and co-author on the paper.

    Further confirmation of this event came from complementary data taken by the Hartebeesthoek Radio Astronomy Observatory in South Africa.


    Hartebeesthoek Radio Astronomy Observatory, located west of Johannesburg South Africa

    This single-dish observatory was monitoring the radio signals from masers in the same region. Masers are the naturally occurring cosmic radio equivalent of lasers. They are powered by a variety of energetic processes throughout the universe, including outbursts from rapidly growing stars.

    The data from the Hartebeesthoek observatory reveal an abrupt and dramatic spike in maser emission from this region in early 2015, only a few months before the first ALMA observation. Such a spike is precisely what astronomers would expect to see if there were a protostar undergoing a major growth spurt.

    “These observations add evidence to the theory that star formation is punctuated by a sequence of dynamic events that build up a star, rather than a smooth continuous growth,” concluded Hunter. “It also tells us that it is important to monitor young stars at radio and millimeter wavelengths, because these wavelengths allow us to peer into the youngest, most deeply embedded star-forming regions. Catching such events at the earliest stage may reveal new phenomena of the star-formation process.”

    This research is presented in a paper titled “An extraordinary outburst in the massive protostellar system NGC6334I-MM1: Quadrupling of the millimeter continuum,” by T.R. Hunter et al., published in the Astrophysical Journal Letters [https://arxiv.org/abs/1701.08637].

    See the full article here .

    Please help promote STEM in your local schools.
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    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 8:39 pm on February 7, 2017 Permalink | Reply
    Tags: ALMA Reveals the Structure of a Low-Mass Protostar System, , , , Millimeter/submillimeter astronomy, , The protostar L1527 IRS also known as IRAS 04368+2557   

    From ALMA: “ALMA Reveals the Structure of a Low-Mass Protostar System” 

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

    08 February 2017
    Dr. Nami Sakai
    RIKEN Star and Planet Formation Laboratory, Japan
    Email: nami.sakai@riken.jp
    Tel: +81-(0)48-467-1411

    Nicolás Lira T.
    Press Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nicolas.lira@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

    1
    Artist’s impression of L1527

    2
    The protostar L1527 IRS, also known as IRAS 04368+2557, as seen by NASA’s Spitzer Space Telescope (John Tobin)

    A team of astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the almost edge-on system of the low-mass protostar L1527. This protostar is in a star forming region in the Taurus molecular cloud, about 450 light years away and has a spinning protoplanetary disk, almost edge-on to our view, embedded in a large envelope of molecules and dust. ALMA allowed the researchers to resolve for the first time the structure of this young stellar system.

    One of the big puzzles in astrophysics is how stars like the Sun manage to form from collapsing molecular clouds in star-forming regions of the Universe. The puzzle is known technically as the angular momentum problem in stellar formation. The problem essentially is that the gas in the star-forming cloud have some rotation, which gives each element of the gas an amount of angular momentum. As they collapse inward, eventually they reach a state where the gravitational pull of the nascent star is balanced by the centrifugal force, so that they will no longer collapse inward of a certain radius unless they can shed some of the angular momentum. This point is known as the centrifugal barrier.

    Now, using measurements taken by ALMA’s radio antennas, a group led by Nami Sakai of the RIKEN Star and Planet Formation Laboratory has found clues as to how the gas in the cloud can find their way to the surface of the forming star. To gain a better understanding of the process, Sakai and her group turned to the ALMA observatory, a network of 66 radio dishes located high in the Atacama Desert of northern Chile. The dishes are connected in a carefully choreographed configuration so that they can provide images on radio emissions from protostellar regions around the sky.

    3
    Integrated intensity distributions of CCH and SO, two important molecules, superposed on the 0.8 mm dust continuum map. The IRE traced by CCH is broadened inward of the radius of about 150 au.

    Previously, Sakai had discovered, from observations of molecules around the same protostar, that unlike the commonly held hypothesis, the transition from envelope to the inner disk—which later forms into planets—was not smooth but very complex. “As we looked at the observational data,” says Sakai, “we realized that the region near the centrifugal barrier—where particles can no longer infall—is quite complex, and we realized that analyzing the movements in this transition zone could be crucial for understanding how the envelope collapses.”

    The new observations show a broadening of the envelope in the transition zone between the inner disk and the outer envelope. Sakai compares it to a “traffic jam in the region just outside the centrifugal barrier, where the gas heats up as the result of a shock wave.” And he adds that “It became clear from the observations that a significant part of the angular momentum is lost by gas being cast in the vertical direction from the flattened protoplanetary disk that formed around the protostar.”

    This behavior accorded well with digital simulations the group had done using a purely ballistic model, where the particles behave like simple projectiles that do not need to be influenced by magnetic or other forces.

    Sakai plan to continue to use observations from the powerful ALMA array “to further refine the understanding of the dynamics of stellar formation and fully explain how matter collapses onto the forming star. This work could also help to better understand the evolution of our own Solar System.”

    Additional information

    The research was published in the Monthly Notices of the Royal Astronomical Society published by Oxford University Press as Sakai, Nami et al., Vertical Structure of the Transition Zone from Infalling Rotating Envelope to Disk in the Class 0 Protostar, IRAS04368+2557.

    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 4:27 pm on January 25, 2017 Permalink | Reply
    Tags: , , , Milky-Way-Like Galaxies Seen in their Awkward Adolescent Years, Millimeter/submillimeter astronomy, ,   

    From NRAO: “Milky-Way-Like Galaxies Seen in their Awkward Adolescent Years” 

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    December 20, 2016
    Charles Blue
    NRAO Public Information Officer
    +1 434.296.0314;
    cblue@nrao.edu

    1
    Four Milky-Way-like progenitor galaxies as seen as they would have appeared 9 billion years ago. ALMA observations of carbon monoxide (red) is superimposed on images taken with the Hubble Space Telescope. The carbon monoxide would most likely be suffused throughout the young galaxies. Credit. ALMA (ESO/NAOJ/NRAO) C. Papovich; A. Angelich (NRAO/AUI/NSF); NASA/ESA Hubble Space Telescope

    Spiral galaxies like our own Milky Way were not always the well-ordered, pinwheel-like structures we see in the universe today. Astronomers believe that about 8-10 billion years ago, progenitors of the Milky Way and similar spiral galaxies were smaller, less organized, but amazingly rich in star-forming material; so much so, that they would have been veritable star factories, churning out new stars faster than at any other point in their lifetimes. Now, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have found evidence to support this view. By studying four very young versions of galaxies like the Milky Way as they were seen approximately 9 billion years ago, the astronomers discovered that each galaxy was incredibly rich in carbon monoxide gas, a well-known tracer of star-forming gas. “We used ALMA to detect adolescent versions of the Milky Way and found that such galaxies do indeed have much higher amounts of molecular gas, which would fuel rapid star formation,” said Casey Papovich, an astronomer at Texas A&M University in College Station and lead author on a paper appearing in Nature Astronomy. “I liken these galaxies to an adolescent human who consumes prodigious amounts of food to fuel their own growth during their teenage years.” Though the relative abundance of star-forming gas is extreme in these galaxies, they are not yet fully formed and rather small compared to the Milky Way as we see it today. The new ALMA data indicate that the vast majority of the mass in these galaxies is in cold molecular gas rather than in stars. These observations, the astronomers note, are helping build a complete picture of how matter in Milky-Way-size galaxies evolved and how our own galaxy formed.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

    ALMA Array

    NRAO ALMA

    GBO radio telescope, Green Bank, West Virginia, USA
    Green Bank Observatory radio telescope, Green Bank, West Virginia, USA, formerly supported by NSF, but now on its own
    NRAO VLA
    NRAO VLA

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

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

     
  • richardmitnick 1:05 pm on January 16, 2017 Permalink | Reply
    Tags: , , , , , Millimeter/submillimeter astronomy, ,   

    From Motherboard: “An Earth-Sized Telescope is About to ‘See’ a Black Hole For the First Time” 

    motherboard

    Motherboard

    January 13, 2017
    William Rauscher

    We were perched dizzyingly high in the Chilean Andes, ringed by a herd of sixty-six white giants. Through the broad windows of the low, nondescript building in which we stood, we could see massive white radio antennas outside against the Martian-red soil of the desolate Chajnantor Plateau, their dishes thrust towards a pure blue sky.

    This is the Atacama Large Millimeter Array, also known as ALMA—one of the world’s largest radio telescope arrays, an international partnership that spans four continents. In spring of 2017, ALMA, along with eight other telescopes around the world, will aim towards the center of the Milky Way, around 25,000 light years from Earth, in an attempt to capture the first-ever image of a black hole. This is part of a daring astronomy project called the Event Horizon Telescope (EHT).

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

    My partner Dave Robertson and I took turns huffing from a can of oxygen to stave off the altitude sickness that can come on at 16,500 feet. Our guide Danilo Vidal, an energetic Chilean who wore his dark hair in a ponytail, pointed to a grey metal door with a glass window. “If we open that door,” said Vidal, “everyone in science will hate us for the rest of our lives.” Confused by this cryptic statement, I took another hit from the oxygen and peered through the glass, into the heart of the experiment.

    Among a small forest of processors, I could see an eggshell-white box that resembled a dorm room refrigerator. Inside was the brand-new maser, an ultraprecise atomic clock that syncs up every antenna on-site, and then syncs ALMA itself to the Event Horizon Telescope’s global network, lending so much dish-space and processing power that it effectively doubles the entire network’s resolution.

    1
    Christophe Jacques of the NRAO inspects the wiring on ALMA’s new hydrogen maser atomic clock during installation. Image: Carlos Padilla/NRAO/AUI/NSF

    To keep equipment from overheating, the room is kept at an absurdly low temperature—very close to absolute zero. If we opened the door, Vidal explained, emergency systems would instantly shut down the maser to protect it, and ALMA’s beating heart would stop, ruining multiple international astronomy projects, including the EHT.

    Claudio Follert, an ALMA fiber-optic specialist in his mid-fifties, was there in 2014 when the maser first arrived—he told me it was a machine he had never seen before, carried in by strange men. The men were sent by the EHT, which is based out of MIT.

    The EHT is made possible by the maser’s astonishing precision—about one billion times more precise than the clock in your smartphone.

    Designed by an international team led by MIT scientist Shep Doeleman, the EHT is the first of its kind-a global telescope network that uses a technique called interferometry to synthesize astronomical data from multiple sources, each with its own maser—including ALMA in Chile, the Large Millimeter Telescope atop the Sierra Negra volcano in Mexico, and the National Radio Astronomy Observatory in Virginia.

    Together, these telescopes create a super-telescope that is quite literally the size of the Earth, with enough resolution to photograph an orange on the Moon.

    With ALMA recently added to this Avengers-like team of radio telescopes, the network is ten times more sensitive. As a result, Doeleman’s group believes it has the firepower to penetrate the interstellar gases that cloak their targets: supermassive black holes. Drawn into orbit by the black holes’ gravity, these gases form gargantuan clouds that yield nothing to optical telescopes.

    Faint radio signals from the black holes, on the other hand, slip through the gas clouds and are ultimately detected on Earth.

    Black holes are the folk legends of outer space. Since no light can escape them, they’re invisible to the eye, and we have no confirmation that they actually exist—only heaps of indirect evidence, particularly the gravitational wobbles in orbits of nearby stars, the behavior of interstellar gas clouds, and the gaseous jets that spew into space when an unseen source of extreme gravity appears to rip cosmic matter to shreds.

    Black holes challenge our most fundamental beliefs about reality. Visionary scientific minds, including the theoretical physicists Stephen Hawking and Kip Thorne, have devoted entire books to unpacking the hallucinatory scenarios thought to be induced by black holes’ gravitational forces—imagine the bottom of your body violently wrenched away from the top, physically stretching you like a Looney Tunes character, a scenario that Thorne’s Black Holes and Time Warps paints in stomach-churning detail.

    2
    An image from the heart of the Milky Way from NASA’s Chandra X-ray Observatory. The supermassive black hole is at the center. Image: NASA/CXC/MIT/F. Baganoff et al.

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    Sag A*  NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    Black holes are thought to lurk at the centers of galaxies including our own. Prove the existence of Sagittarius A*, the supermassive black hole at the heart of the Milky Way, and you are one step closer to solving another mystery: the origin of humankind, and all life as we know it.

    “The black hole at the center of our galaxy has everything to do with our own origin,” said Violette Impellizzeri, an ALMA astronomer collaborating with Event Horizon Telescope. Supermassive black holes are thought to regulate the stars that surround them, influencing their formation and orbit. “Understanding how our galaxy was formed leads to our own origin directly,” she said.

    Scientists estimate the mass of Sagittarius A* to be four million times that of our Sun, yet its diameter is roughly equal to the distance from our sun to Mercury—not much, in cosmic terms. The resulting density produces gravity so strong that space and time distort around it, making it invisible.

    The current theory, espoused by Thorne, is that the distance from the center of a black hole, known as the singularity, to its edge, known as the event horizon, becomes so warped that it nears infinite length, and light simply runs out of energy as it tries to escape.

    It took Doeleman, the project leader at MIT, to decide that in order to see the unseeable, you would first have to create a new kind of vision. With ALMA as part of the giant EHT network, we can take a radio “photograph” of the matter that orbits Sagittarius A*—called the accretion disk—and finally see the black hole in shadow: its first-ever portrait.

    • Vidal and Follert, the guide and fiber-optic specialist, led us out onto the plateaus. There was work to do: one of the antennas was hobbled by a damaged radio receptor.

    It was blindingly bright and windy, not to mention dry—Chajnantor is located in Chile’s Atacama Desert, the driest place on Earth, if you don’t count the poles. Completely inhospitable for human beings, Chajnantor is an ideal setting for a radio telescope: the elevation puts it closer to the stars, and the strikingly low water vapor keeps the cosmic signals pristine.

    For some, like ALMA’s crew, as well as Doeleman, the extreme environment is part of the attraction. “I just love getting to the telescopes,” he said. At 50, Doeleman is fresh-faced, with glasses and thinning hair that make him look every part the bookish scientist. His outgoing personality and entrepreneurial vigor reflect an explorer’s spirit more at home in the field than behind a desk.

    Doeleman regularly travels to each EHT site around the world, many of them located in extreme environments like the Andes or the Sierra Negra. “The adventure part is what motivates me—driving along dirt roads, up the sides of mountains, to install new instruments, doing observations that have never been done before. It’s a little bit like Jacques Cousteau—we’re not sitting in armchairs in our offices.”

    Outside on Chajnantor, I felt light-headed. I tried to keep my breathing steady: low oxygen can quickly wreck your mental faculties. On the plateau, Dave and I were dwarfed by ALMA’s antennas, which blocked out the desert sun. They felt powerful and eerie, like Easter Island statues. Even when standing directly beneath these behemoths, it wasn’t clear how they were controlled—the white dishes seemed to twist and pivot without warning.

    3
    Using a technique called interferometry, ALMA’s antennas can be configured to act as one giant antenna, and ALMA itself can be synced up with telescopes worldwide. Image: Dave Robertson

    An ALMA antenna is useless when one of its radio receptors is out of tune. We followed Follert up several steel ladders, boots clanging on metal, until we were in a low-ceilinged maintenance room inside one of the antennas. We helped him remove the damaged receptor, a long metal cylinder resembling a futuristic bazooka.

    Vidal drove us back down the mountain to the Operations Support Facility (OSF), ALMA’s headquarters, so we could see the lab where receptors are maintained.

    Per strict international regulations, Vidal was required to breathe through an oxygen tube as he drove, lest the high altitude cause him to lose consciousness behind the wheel.

    As we descended, Vidal radioed at regular intervals to identify our location. All around us the mountain slopes were red, rocky and barren—no wonder that NASA regularly deploys expeditions to this desert to replicate conditions on Mars.

    Located at 9,000 ft, the OSF is where ALMA’s staff call home: a total of 600 scientists working in shifts are based here, including engineers and technicians, from over 20 countries. The working conditions can be extreme. Staff hole up in weeklong shifts separated from friends and family, and endure the short and long-term health risks of high elevation, including a stroke or pulmonary edema, where fluid fills your lungs and you suffocate.

    It is thus maybe not surprising to find out that the entire staff are monitored regularly by medical personnel, and that emergency oxygen and a hyperbaric chamber are on-hand.

    They unwind by exercising and watching movies, although certain sci-fi flicks are frowned upon. “We need a break from space sometimes,” said Follert. Alcohol consumption on site is strictly forbidden—have even a tipple and you risk amplifying the physical effects of high elevation.

    4
    Aerial picture of ALMA’s Operations Support Facility. Image: Carlos Padilla/NRAO/AUI/NSF

    The close teamwork at ALMA is absolutely essential for the life of the observatory. Detecting cosmic radio signals, including those sent from a black hole, requires constant cooperation across teams, who must obsessively calibrate, maintain and repair their instruments to fend off unwanted noise.

    ALMA and the other telescopes on the EHT will soon turn towards the center of the Milky Way to tune in to the black hole’s narrow radio frequency. The data that ALMA collects will be so large, it cannot be transferred online. Instead, physical hard drives will shipped by “sneakernet”: loaded into the belly of a 747 and flown directly to MIT.

    When ALMA’s data is correlated with the other telescopes later this year, Sagittarius A* should appear against the glowing gas of the accretion disk. Maybe.

    Actually, said Doeleman, “we don’t know what we’re going to see. Nature can be cruel. We may see something boring. But we’re not married to one outcome—we’re going to see nature the way nature is.”

    See the full article here .

    The full EHT:

    Event Horizon Telescope Array

    Event Horizon Telescope map

    The locations of the radio dishes that will be part of the Event Horizon Telescope array. Image credit: Event Horizon Telescope sites, via University of Arizona at https://www.as.arizona.edu/event-horizon-telescope.

    Arizona Radio Observatory
    Arizona Radio Observatory/Submillimeter-wave Astronomy (ARO/SMT)

    ESO/APEX
    Atacama Pathfinder EXperiment (APEX)

    CARMA Array no longer in service
    Combined Array for Research in Millimeter-wave Astronomy (CARMA)

    Atacama Submillimeter Telescope Experiment (ASTE)
    Atacama Submillimeter Telescope Experiment (ASTE)

    Caltech Submillimeter Observatory
    Caltech Submillimeter Observatory (CSO)

    IRAM NOEMA interferometer
    Institut de Radioastronomie Millimetrique (IRAM) 30m

    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA
    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA

    Large Millimeter Telescope Alfonso Serrano
    Large Millimeter Telescope Alfonso Serrano

    CfA Submillimeter Array Hawaii SAO
    Submillimeter Array Hawaii SAO

    Future Array/Telescopes

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array, Chile

    Plateau de Bure interferometer
    Plateau de Bure interferometer

    South Pole Telescope SPTPOL
    South Pole Telescope SPTPOL

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    The future is wonderful, the future is terrifying. We should know, we live there. Whether on the ground or on the web, Motherboard travels the world to uncover the tech and science stories that define what’s coming next for this quickly-evolving planet of ours.

    Motherboard is a multi-platform, multimedia publication, relying on longform reporting, in-depth blogging, and video and film production to ensure every story is presented in its most gripping and relatable format. Beyond that, we are dedicated to bringing our audience honest portraits of the futures we face, so you can be better informed in your decision-making today.

     
    • Jim Ruebush 1:51 pm on January 16, 2017 Permalink | Reply

      Very interesting. I look forward to seeing results. The radio telescopes at Atacama are the subject of a blog post of mine a few years ago. http://bit.ly/2jpp7hl

      Only 2 miles from my home in Iowa is a radio telescope part of the VLBA. I’ve been fortunate to go up inside and stand in the dish. What fun.

      Keep up the good work and posts.

      Like

  • richardmitnick 3:00 pm on December 12, 2016 Permalink | Reply
    Tags: , ALMA Finds Compelling Evidence for Pair of Infant Planets around Young Star, , , Millimeter/submillimeter astronomy,   

    From ALMA: “ALMA Finds Compelling Evidence for Pair of Infant Planets around Young Star” 

    ALMA Array

    ALMA

    09 December 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: nicolas.lira@alma.cl

    Laura Pérez
    Max Planck Institute for Radioastronomy
    Bonn, Germany
    Email: lperez@mpifr-bonn.mpg.de

    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

    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
    Composite image of the protoplanetary disk surrounding the young star HD 163296. The inner red area shows the dust of the protoplanetary disk. The broader blue disk is the carbon monoxide gas in the system. ALMA observed that in the outer two gaps in the dust, there was a significant dip in the concentration of carbon monoxide, suggesting two planets are forming there. Credit: ALMA (ESO/NAOJ/NRAO); A. Isella; B. Saxton (NRAO/AUI/NSF)

    Astronomers now know that our galaxy is teeming with planets, from rocky worlds roughly the size of Earth to gas giants bigger than Jupiter. Nearly every one of these exoplanets has been discovered in orbit around a mature star with a fully evolved planetary system.

    New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) contain compelling evidence that two newborn planets, each about the size of Saturn, are in orbit around a young star known as HD 163296. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star’s protoplanetary disk.

    2
    ALMA image of the protoplanetary disk surrounding the young star HD 163296 as seen in dust. New observations suggested that two planets, each about the size of Saturn, are in orbit around the star. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star’s protoplanetary disk. Credit: ALMA (ESO/NAOJ/NRAO); A. Isella; B. Saxton (NRAO/AUI/NSF)

    Previous observations of other young star systems have helped to reshape our understanding of planet formation. For example, ALMA’s images of HL Tauri and TW Hydrae revealed striking gaps and prominent ring structures in the stars’ dusty disks. These features may be the tantalizing first signs that planets are being born. Remarkably, these signs appeared around much younger stars than astronomers thought possible, suggesting that planet formation can begin soon after the formation of a protoplanetary disk.

    “ALMA has shown us amazing images and never-before-seen views of the rings and gaps around young stars that could be the hallmarks of planet formation. However, since we were only looking at the dust in the disks with sufficient detail, we couldn’t be sure what created these features,” said Andrea Isella, an astronomer at Rice University in Houston, Texas, and lead author on a paper published in Physical Review Letters.

    In studying HD 163296, the research team used ALMA to trace, for the first time, the distribution of both the dust and the carbon monoxide (CO) gas components of the disk at roughly the same level of detail.

    These observations revealed three distinct gaps in HD 163296’s dust-filled protoplanetary disk. The first gap is located approximately 60 astronomical units from the central star, which is about twice the distance from our Sun to Neptune (An astronomical unit – AU – is the average distance from the Earth to the Sun.). The other two gaps are 100 AU and 160 AU from the central star, well beyond the extent of our solar system’s Kuiper Belt, the region of icy bodies beyond the orbit of Neptune.

    Using ALMA’s ability to detect the faint millimeter-wavelength “glow” emitted by gas molecules, Isella and his team discovered that there was also an appreciable dip in the amount of CO in the outer two dust gaps.

    By seeing the same features in both the gas and the dust components of the disk, the astronomers believe they have found compelling evidence that there are two planets coalescing remarkably far from the central star. The width and depth of the two CO gaps suggest that each potential planet is roughly the same mass as Saturn, the astronomers said.

    In the gap nearest to the star, the team found little to no difference in the concentration of CO gas compared to the surrounding dusty disk. This means that the innermost gap could have been produced by something other than an emerging planet.

    4
    Artist impression of the protoplanetary disk surrounding the young star HD 163296. By studying the dust (ruddy brown) and carbon monoxide gas (light blue) profiles of the disk, astronomers discovered tantalizing evidence that two planets are forming in the outer two dust gaps in the disk. Credit: B. Saxton, NRAO/AUI/NSF

    “Dust and gas behave very differently around young stars,” said Isella. “We know, for example, that there are certain chemical and physical process that can produce ringed structures in the dust like the ones we have seen previously. We certainly believe these structures could be the work of a nascent planet plowing through the dust, but we simply can’t rule out other possible explanations. Our new observations provide intriguing evidence that planets are indeed forming around this one young star.”

    HD 163296 is roughly 5 million years old and about twice the mass of the Sun. It is located approximately 400 light-years from Earth in the direction of the constellation Sagittarius.

    Additional information

    This research is presented in a paper titled Ringed structure of the HD 163296 disk revealed by ALMA, by Isella et al., published in Physical Review Letters.

    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 9:33 am on December 5, 2016 Permalink | Reply
    Tags: , ALMA measures size of planets’ seeds, , , HD 142527, Millimeter/submillimeter astronomy, , Radio-wave polarization   

    From ALMA: “ALMA measures size of planets’ seeds” 

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

    05 December 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: nicolas.lira@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

    1
    Dust disk around the young star HD 142527 observed with ALMA. Credit: ALMA (ESO/NAOJ/NRAO), Kataoka et al.

    Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA), have for the first time, achieved a precise size measurement of small dust particles around a young star through radio-wave polarization. ALMA’s high sensitivity for detecting polarized radio waves made possible this important step in tracing the formation of planets around young stars.

    Astronomers have believed that planets are formed from gas and dust particles, although the details of the process have been veiled. One of the major enigmas is how dust particles as small as 1 micrometer aggregate to form a rocky planet with a diameter of 10 thousand kilometers. Difficulty in measuring the size of dust particles has prevented astronomers from tracing the process of dust growth.

    2
    Artist’s impression of a dust ring around the young star HD 142527. Dust around the star has an asymmetric distribution. Credit: NAOJ

    Akimasa Kataoka, a Humboldt Research Fellow stationed at Heidelberg University and the National Astronomical Observatory of Japan (NAOJ), tackled this problem. He and his collaborators have theoretically predicted that, around a young star, radio waves scattered by the dust particles should carry unique polarization features. He also noticed that the intensity of polarized emissions allows us to estimate the size of dust particles far better than other methods.

    To test their prediction, the team led by Kataoka observed the young star HD 142527 with ALMA [1] and discovered, for the first time, the unique polarization pattern in the dust disk around the star. As predicted, the polarization has a radial direction in most parts of the disk, but at the edge of the disk, the direction is flipped perpendicular to the radial direction.

    Comparing the observed intensity of the polarized emissions with the theoretical prediction, they determined that the size of the dust particles is at most 150 micrometers. This is the first estimation of the dust size based on polarization. Surprisingly, this estimated size is more than 10 times smaller than previously thought.

    “In the previous studies, astronomers have estimated the size based on radio emissions assuming hypothetical spherical dust particles,” explains Kataoka. “In our study, we observed the scattered radio waves through polarization, which carries independent information from the thermal dust emission. Such a big difference in the estimated size of dust particles implies that the previous assumption might be wrong.”

    3
    Polarization pattern obtained by ALMA around the young star HD 142527. Contours show the total intensity of dust emissions and the color image shows the intensity of polarized emissions. White bars show the direction of polarization. Credit: ALMA (ESO/NAOJ/NRAO), Kataoka et al.

    The team’s idea to solve this inconsistency is to consider fluffy, complex-shaped dust particles, not simple spherical dust [2] . In the macroscopic view, such particles are indeed large, but in the microscopic view, each small part of a large dust particle scatters radio waves and produces unique polarization features. Per the present study, astronomers obtain these “microscopic” features through polarization observations. This idea might prompt astronomers to reconsider the previous interpretation of observational data.

    “The polarization fraction of radio waves from the dust disk around HD 142527 is only a few percent. Thanks to ALMA’s high sensitivity, we have detected such a tiny signal to derive information about the size and shape of the dust particles,” said Kataoka. “This is the very first step in the research on dust evolution with polarimetry, and I believe the future progress will be full of excitement.”

    Notes

    [1]. HD 142527 is located 500 light-years away from the Earth, in the direction of the constellation Lupus, the Wolf. The age of the star is estimated to be 5 million years old and its mass twice that of the Sun. HD 142527 is a popular target among astronomers to study planet formation and several findings about it have previously been reported from ALMA (for example, “ALMA Discovers a Formation Site of a Giant Planetary System”) and the Subaru Telescope (for example, “Diversity the Norm in Protoplanetary Disks: Astronomers Find Donuts, Spirals and Now Banana Splits”).

    [2]. Prior to the ALMA observations, Kataoka had propounded fluffy dust particles around young stars. Such particles are not only favored to explain ALMA’s observational results, but also help overcome other big problems in the dust aggregation process. For details, see the press release “The seeds of planets are fluffy” issued in 2013.

    Additional information

    These observation results were published as Kataoka et al. Millimeter Polarization Observation of the Protoplanetary Disk around HD 142527 in the Astrophysical Journal Letters in November 2016.

    The research team members are:

    Akimasa Kataoka (Humboldt Research Fellowship for Postdoctoral Researchers / Heidelberg University / National Astronomical Observatory of Japan / former Postdoctral Fellowship for Research Abroad at Japan Society for Promoting Science), Takashi Tsukagoshi (Ibaraki University), Munetake Momose (Ibaraki University), Hiroshi Nagai (National Astronomical Observatory of Japan), Takayuki Muto (Kogakuin University), Cornelis P. Dullemond (Heidelberg University), Adriana Pohl (Heidelberg University / Max Planck Institute for Astronomy), Misato Fukagawa (Nagoya University), Hiroshi Shibai (Osaka University), Tomoyuki Hanawa (Chiba University), Koji Murakawa (Osaka Sangyo University)

    This research was supported by a Grant-in-Aid from the Japan Society for the Promotion of Science and the Ministry of Education, Culture, Sports, Science and Technology, Japan (No. 23103004、15K17606、26800106).

    See the full article here .

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    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 4:28 pm on December 1, 2016 Permalink | Reply
    Tags: , , , II Zw 40, Millimeter/submillimeter astronomy, ,   

    From UCLA: “UCLA astronomers watch star clusters spewing out dust” 

    UCLA bloc

    UCLA

    December 01, 2016
    Katherine Kornei

    1
    In the galaxy II Zw 40, dust (shown in yellow) is strongly associated with clusters of stars (shown in orange). UCLA researchers have used new observations of this galaxy to confirm that these stars are creating enormous amounts of dust. S. M. Consiglio et al., Astrophysical Journal Letters, 2016

    Galaxies are often thought of as sparkling with stars, but they also contain gas and dust. Now, a team led by UCLA astronomers has used new data to show that stars are responsible for producing dust on galactic scales, a finding consistent with long-standing theory. Dust is important because it is a key component of rocky planets such as Earth.

    This research is published online today in the Astrophysical Journal Letters.

    Jean Turner, a UCLA professor in the department of astronomy and physics, her graduate student S. Michelle Consiglio, and two other collaborators observed a galaxy roughly 33 million light-years away. The researchers focused on this galaxy, called “II Zw 40,” because it is vigorously forming stars and therefore useful for testing theories of star formation. “This galaxy has one of the largest star-forming regions in the local universe,” Turner said.

    The researchers, led by Consiglio, obtained images of II Zw 40 using the Atacama Large Millimeter/submillimeter Array telescope. This telescope, located in Chile’s Atacama desert, is composed of an array of 66 individual telescopes that function as a single large observatory.

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

    In 2011, Turner took a three-month sabbatical from UCLA to help prepare the Atacama Array to be used by the astronomical community. “I helped with reducing data and served as astronomer on duty,” she said.

    The telescope is sensitive to light in the millimeter and submillimeter part of the electromagnetic spectrum, just slightly shorter than microwaves. Capturing this kind of light requires a telescope at high altitudes — this one is built on a plateau at 16,400 feet — because “the Earth’s atmosphere is beginning to absorb very strongly at those wavelengths,” Turner said. “All ALMA scientists work at a lower elevation because you can’t think well at that altitude,” she added.

    Consiglio and her team observed the central region of II Zw 40, a part of the galaxy with two young clusters of stars, each containing roughly a million stars. By imaging II Zw 40’s star clusters at different wavelengths, they constructed a map that traced the dust in the galaxy. Astronomical dust — made mostly of carbon, silicon and oxygen — is prevalent in the universe. “If you look at the Milky Way in the sky, it looks kind of patchy and splotchy. That’s due to dust blocking the light,” Turner said.

    The researchers tested whether the location of the galaxy’s dust was consistent with the location of the galaxy’s star clusters. They found that it was: Consiglio and her team showed that II Zw 40’s dust was concentrated within roughly 320 light-years of the star clusters. “The dust is all focused near the double cluster,” Turner said. This observation supported their hypothesis that stars are responsible for producing dust. “The double cluster is a ‘soot factory’ polluting its local environment,” Consiglio said.

    Scientists have long theorized that stars produce dust by expelling the elements fused deep within their interiors, enriching their host galaxies in elements heavier than hydrogen and helium. However, astronomical data have thus far not backed up that claim. “People have looked for this large-scale enrichment of galaxies, but they haven’t seen it before,” Turner said. “We’re seeing galaxy-scale enrichment and we see clearly where it is coming from.”

    The researchers propose that the dust enrichment is so obvious in II Zw 40’s star clusters because they contain large numbers of very young, massive stars, which are the producers of dust. “The evolutionary time scales of these stars are short enough that you see the dust before it has a chance to get dispersed very far from its source,” Turner said. “We’re looking at the best place to see dust enrichment, in large star clusters,” Consiglio added.

    These new results motivate the team to observe more star clusters. “This is a snapshot of a double cluster at one age in one galaxy,” Turner said. “Our goal now is to find other sources and look at them in different stages of evolution to better understand the evolution of these giant star clusters and how they enrich their environment in dust.”

    See the full article here .

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    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 1:56 pm on November 4, 2016 Permalink | Reply
    Tags: , , , Galaxies IC 2163 (left) and NGC 2207 (right) recently grazed past each other triggering a tsunami of stars and gas in IC 2163 and producing the dazzling eyelid-like features there., Millimeter/submillimeter astronomy, Tsunami of Stars and Gas Produces Dazzling Eye-shaped Feature in Galaxy   

    From ALMA: “Tsunami of Stars and Gas Produces Dazzling Eye-shaped Feature in Galaxy” 

    ALMA Array

    ALMA

    04 November 2016
    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

    Cell: +56 9 75871963
    Email: valeria.foncea@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

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    Galaxies IC 2163 (left) and NGC 2207 (right) recently grazed past each other, triggering a tsunami of stars and gas in IC 2163 and producing the dazzling eyelid-like features there. ALMA image of carbon monoxide (orange), which revealed motion of the gas in these features, is shown on top of Hubble image (blue) of the galaxy pair. Credit: M. Kaufman; B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble Space Telescope

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered a tsunami of stars and gas that is crashing midway through the disk of a spiral galaxy known as IC 2163. This colossal wave of material – which was triggered when IC 2163 recently sideswiped another spiral galaxy dubbed NGC 2207 – produced dazzling arcs of intense star formation that resemble a pair of eyelids.

    “Although galaxy collisions of this type are not uncommon, only a few galaxies with eye-like, or ocular, structures are known to exist,” said Michele Kaufman, an astronomer formerly with The Ohio State University in Columbus and lead author on a paper published today in the Astrophysical Journal.

    Kaufman and her colleagues note that the paucity of similar features in the observable universe is likely due to their ephemeral nature.

    “Galactic eyelids last only a few tens of millions of years, which is incredibly brief in the lifespan of a galaxy. Finding one in such a newly formed state gives us an exceptional opportunity to study what happens when one galaxy grazes another,” said Kaufman.

    The interacting pair of galaxies resides approximately 114 million light-years from Earth in the direction of the constellation Canis Major. These galaxies brushed past each other – scraping the edges of their outer spiral arms — in what is likely the first encounter of an eventual merger.

    Using ALMA’s remarkable sensitivity and resolution, the astronomers made the most detailed measurements ever of the motion of carbon monoxide gas in the galaxy’s narrow eyelid features. Carbon monoxide is a tracer of molecular gas, which is the fuel for star formation.

    The data reveal that the gas in the outer portion of IC 2163’s eyelids is racing inward at speeds in excess of 100 kilometers a second. This gas, however, quickly decelerates and its motion becomes more chaotic, eventually changing trajectory and aligning itself with the rotation of the galaxy rather than continuing its pell-mell rush toward the center.

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    Dazzling eyelid-like features bursting with stars in galaxy IC 2163 formed from a tsunami of stars triggered by a glancing collision with galaxy NGC 2207 (a potion of its spiral arm is shown on right side of image). ALMA image of carbon monoxide (orange), which revealed motion of the gas in these features, is shown on top of Hubble image (blue) of the galaxy. Credit: M. Kaufman; B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble Space Telescope

    “What we observe in this galaxy is very much like a massive ocean wave barreling toward shore until it interacts with the shallows, causing it to lose momentum and dump all of its water and sand on the beach,”

    said Bruce Elmegreen, a scientist with IBM’s T.J. Watson Research Center in Yorktown Heights, New York, and co-author on the paper.

    “Not only do we find a rapid deceleration of the gas as it moves from the outer to the inner edge of the eyelids, but we also measure that the more rapidly it decelerates, the denser the molecular gas becomes,”

    said Kaufman.

    “This direct measurement of compression shows how the encounter between the two galaxies drives gas to pile up, spawn new star clusters and form these dazzling eyelid features.”

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    Annotated image showing dazzling eyelid-like features bursting with stars in galaxy IC 2163 formed from a tsunami of stars triggered by a glancing collision with galaxy NGC 2207 (a potion of its spiral arm is shown on right side of image). ALMA image of carbon monoxide (orange), which revealed motion of the gas in these features, is shown on top of Hubble image (blue) of the galaxy. Credit: M. Kaufman; B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble Space Telescope

    Computer models predict that such eyelid-like features could evolve if galaxies interacted in a very specific manner.
    “This evidence for a strong shock in the eyelids is terrific. It’s all very well to have a theory and simulations suggesting it should be true, but real observational evidence is great,”

    said Curtis Struck, a professor of astrophysics at Iowa State University in Ames and co-author on the paper.

    “ALMA showed us that the velocities of the molecular gas in the eyelids are on the right track with the predictions we get from computer models,”

    said Kaufman.

    “This critical test of encounter simulations was not possible before.”

    Astronomers believe that such collisions between galaxies were common in the early universe when galaxies were closer together. At that time, however, galactic disks were generally clumpy and irregular, so other processes likely overwhelmed the formation of similar eyelid features.

    The authors continue to study this galaxy pair and currently are comparing the properties (e.g., locations, ages, and masses) of the star clusters previously observed with NASA’s Hubble Space Telescope with the properties of the molecular clouds observed with ALMA. They hope to better understand the differences between molecular clouds and star clusters in the eyelids and those elsewhere in the galaxy pair.

    See the full article here .

    Please help promote STEM in your local schools.
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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 11:11 am on November 1, 2016 Permalink | Reply
    Tags: , , Millimeter/submillimeter astronomy,   

    From ESO’s Oana Sandu: The eyes of ALMA! 

    ALMA Array

    ALMA

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    The eyes of #ALMA! The first link in the chain of reception, conversion, processing, and recording of ALMA’s signals is called the ‘Front End’. It is designed to capture signals from 10 different bands of frequency. © S. Otarola – ALMA(ESO/NAOJ/NRAO)

    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

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    NAOJ

     
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