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  • richardmitnick 2:40 pm on October 16, 2019 Permalink | Reply
    Tags: "ALMA Witness Planet Formation in Action", , , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “ALMA Witness Planet Formation in Action” 

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

    From ALMA

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: pio@eso.org

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Cell phone: +1 (434) 249 3423
    Email: alma-pr@nrao.edu

    1
    Artist’s impression of gas flowing like a waterfall into a protoplanetary disk gap, which is most likely caused by an infant planet. Credit: NRAO/AUI/NSF, S. Dagnello.

    2
    Scientists measured the motion of gas (arrows) in a protoplanetary disk in three directions: rotating around the star, towards or away from the star, and up- or downwards in the disk. The inset shows a close-up of where a planet in orbit around the star pushes the gas and dust aside, opening a gap. Credit: NRAO/AUI/NSF, B. Saxton.

    3
    A computer simulation showed that the patterns of gas flows are unique and are most likely caused by planets in three locations in the disk. Planets in orbit around the star push the gas and dust aside, opening gaps. The gas above the gaps collapses into it like a waterfall, causing a rotational flow of gas in the disk. Credit: ALMA (ESO/NAOJ/NRAO), J. Bae; NRAO/AUI/NSF, S. Dagnello.

    For the first time, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have witnessed 3D motions of gas in a planet-forming disk. At three locations in the disk around a young star called HD 163296, gas is flowing like a waterfall into gaps that are most likely caused by planets in formation. These gas flows have long been predicted and would directly influence the chemical composition of planets atmospheres. This research appears in the latest issue of the journal Nature.

    The birthplaces of planets are disks made out of gas and dust. Astronomers study these so-called protoplanetary disks to understand the processes of planet formation. Beautiful images of disks made with ALMA show distinct gaps and ring features in the dust, which may be caused by infant planets.

    To get more certainty that planets cause these gaps, and to get a complete view of planetary formation, scientists study the gas in the disks in addition to dust. Ninety-nine percent of a protoplanetary disk’s mass is gas, of which carbon monoxide (CO) is the brightest component, and ALMA can observe it.

    Last year, two teams of astronomers demonstrated a new planet-hunting technique using this gas. They measured the velocity of CO gas rotating in the disk around the young star HD 163296. Localized disturbances in the movements of the gas revealed three planet-like patterns in the disk.

    In this new study, lead author Richard Teague from the University of Michigan and his team used new high-resolution ALMA data from the Disk Substructures at High Angular Resolution Project (DSHARP) to study the gas’s velocity in more detail. “With the high-fidelity data from this program, we were able to measure the gas’s velocity in three directions instead of just one,” said Teague. “For the first time, we measured the motion of the gas in every possible direction. Rotating around, moving towards or away from the star, and up or downwards in the disk.”

    Teague and his colleagues saw the gas moving from the upper layers towards the middle of the disk at three different locations. “What most likely happens is that a planet in orbit around the star pushes the gas and dust aside, opening a gap,” Teague explained. “The gas above the gap then collapses into it like a waterfall, causing a rotational flow of gas in the disk.”

    This is the best evidence to date that there are indeed planets forming around HD 163296. But astronomers cannot say with one hundred percent certainty that planets cause the gas flows. For example, the star’s magnetic field could also cause disturbances in the gas. “Right now, only direct observation of the planets could rule out the other options. But, the patterns of these gas flows are unique, and very likely, only planets can cause them,” said coauthor Jaehan Bae of the Carnegie Institution for Science, who tested this theory with a computer simulation of the disk.

    The location of the three predicted planets in this study correspond to the results from last year. Their positions probably are at 87, 140, and 237 AU (An astronomical unit – AU – is the average distance from the Earth to the Sun). The closest planet to HD 163296 is calculated to be half the mass of Jupiter, the middle planet is Jupiter-mass, and the farthest planet is twice as massive as Jupiter.

    Gas flows from the surface towards the midplane of the protoplanetary disk have been predicted since the late nineties. But this is the first time that astronomers observed them. Besides being useful to detect infant planets, these flows can also shape our understanding of how gas giant planets obtain their atmospheres.

    “Planets form in the middle layer of the disk, the so-called midplane. This is a cold place, shielded from radiation from the star,” Teague explained. “We think that the gaps caused by planets bring in warmer gas from the more chemically active outer layers of the disk and that this gas will form the atmosphere of the planet.”

    Teague and his team did not expect that they would be able to see this phenomenon. “The disk around HD 163296 is the brightest and biggest disk we can see with ALMA,” said Teague. “But it was a big surprise to see these gas flows so clearly. The disks appear to be much more dynamic than we thought.”

    “This gives us a much more complete picture of planet formation than we ever dreamed,” said coauthor Ted Bergin of the University of Michigan. “By characterizing these flows, we can determine how planets like Jupiter are born and characterize their chemical composition at birth. We might be able to use this to trace the birth location of these planets, as they can move during formation.”

    Additional information

    This research is presented in a paper by R. Teague et al. in Nature.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 1:13 pm on October 15, 2019 Permalink | Reply
    Tags: "ALMA Observes Counter-intuitive Flows Around Black Hole", , , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “ALMA Observes Counter-intuitive Flows Around Black Hole” 

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

    From ALMA

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Bárbara Ferreira
    ESO Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: pio@eso.org

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Cell phone: +1 (434) 249 3423
    Email: alma-pr@nrao.edu

    1
    Artist impression of the heart of galaxy NGC 1068, which harbors an actively feeding supermassive black hole, hidden within a thick doughnut-shaped cloud of dust and gas. ALMA discovered two counter-rotating flows of gas around the black hole. The colors in this image represent the motion of the gas: blue is material moving toward us, red is moving away. Credit: NRAO/AUI/NSF, S. Dagnello.

    2
    ALMA image showing two disks of gas moving in opposite directions around the black hole in galaxy NGC 1068. The colors in this image represent the motion of the gas: blue is material moving toward us, red is moving away. The white triangles are added to show the accelerated gas that is expelled from the inner disk – forming a thick, obscuring cloud around the black hole. Credit: ALMA (ESO/NAOJ/NRAO), V. Impellizzeri; NRAO/AUI/NSF, S. Dagnello.

    At the center of a galaxy called NGC 1068, a supermassive black hole hides within a thick doughnut-shaped cloud of dust and gas. When astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to study this cloud in more detail, they made an unexpected discovery that could explain why supermassive black holes grew so rapidly in the early Universe.

    “Thanks to the spectacular resolution of ALMA, we measured the movement of gas in the inner orbits around the black hole,” explains Violette Impellizzeri of the National Radio Astronomy Observatory (NRAO), working at ALMA in Chile and lead author on a paper published in The Astrophysical Journal Letters. “Surprisingly, we found two disks of gas rotating in opposite directions.”

    Supermassive black holes already existed when the Universe was young, just a billion years after the Big Bang. But how these extreme objects, whose masses are up to billions of times the mass of the Sun, had time to grow so fast, is an outstanding question among astronomers. This new ALMA discovery could provide a clue. “Counter-rotating gas streams are unstable, which means that clouds fall into the black hole faster than they do in a disk with a single rotation direction,” said Impellizzeri. “This could be a way in which a black hole can grow rapidly.”

    NGC 1068 (also known as Messier 77) is a spiral galaxy approximately 47 million light-years from Earth in the direction of the constellation Cetus. At its center is an active galactic nucleus, a supermassive black hole that is actively feeding itself from a thin, rotating disk of gas and dust, also known as an accretion disk.

    Previous ALMA observations revealed that the black hole is gulping down material and spewing out gas at incredibly high speeds. This gas that gets expelled from the accretion disk likely contributes to hiding the region around the black hole from optical telescopes.

    Impellizzeri and her team used ALMA’s superior zoom lens ability to observe the molecular gas around the black hole. Unexpectedly, they found two counter-rotating disks of gas. The inner disk spans 2-4 light-years and follows the rotation of the galaxy, whereas the outer disk (also known as the torus) spans 4-22 light-years and is rotating the opposite way.

    “We did not expect to see this, because gas falling into a black hole would normally spin around it in only one direction,” said Impellizzeri. “Something must have disturbed the flow because it is impossible for a part of the disk to start rotating backward all on its own.”

    Counter-rotation is not an unusual phenomenon in space. “We see it in galaxies, usually thousands of light-years away from their galactic centers,” explained co-author Jack Gallimore from Bucknell University in Lewisburg, Pennsylvania. “The counter-rotation always results from the collision or interaction between two galaxies. What makes this result remarkable is that we see it on a much smaller scale, tens of light-years instead of thousands from the central black hole.”

    The astronomers think that the backward flow in NGC 1068 might be caused by gas clouds that fell out of the host galaxy, or by a small passing galaxy on a counter-rotating orbit captured in the disk.

    At the moment, the outer disk appears to be in a stable orbit around the inner disk. “That will change when the outer disk begins to fall onto the inner disk, which may happen after a few orbits or a few hundred thousand years. The rotating streams of gas will collide and become unstable, and the disks will likely collapse in a luminous event as the molecular gas falls into the black hole. Unfortunately, we will not be there to witness the fireworks,” said Gallimore.

    Additional Information

    The research team was composed by Violette Impellizzeri1,2, Jack F. Gallimore3, Stefi A. Baum4, Moshe Elitzur5, Richard Davies6, Dieter Lutz6, Roberto Maiolino7, Alessandro Marconi8,9, Robert Nikutta10, Christopher P. O’Dea4, and Eleonora Sani11.

    1 Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile

    2 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA

    3 Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837, USA

    4 University of Manitoba, Department of Physics and Astronomy, Winnipeg, MB R3T 2N2, Canada

    5 Astronomy Department, University of California, Berkeley, CA 94720, USA

    6 Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse 1, D-85748 Garching, Germany

    7 Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

    8 Dipartimento di Fisica e Astronomia, Universit’a di Firenze, via G. Sansone 1, I-50019, Sesto Fiorentino (Firenze), Italy

    9 INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50135, Firenze, Italy

    10 National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719, USA

    11 European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
  • richardmitnick 1:37 pm on October 14, 2019 Permalink | Reply
    Tags: "Feeding a Baby Star Through a Whirlpool in Space", , , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “Feeding a Baby Star Through a Whirlpool in Space” 

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

    From ALMA

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Calum Turner
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: calum.turner@eso.org

    Mariya Lyubenova
    ESO Outreach Astronomer
    Garching bei München, Germany
    Phone: +49 89 32 00 61 88
    Email: mlyubeno@eso.org

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    +1 (434) 249 3423
    alma-pr@nrao.edu

    1

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) detected a pair of spiral arms in an accretion disk around a baby star. Interestingly, these spiral density enhancements make the disk appear like a “space whirlpool.” The finding supports current theories of accretion disk feeding process, and potentially brings critical insights into the processes of grain growth and settling that are important to planet formation. These results appear in an article in Nature Astronomy led by Chin-Fei Lee at Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan).

    “Thanks to the resolving power of ALMA, we finally detected a pair of spirals in a young accretion disk around a baby star. These spirals, long predicted in theory, play a crucial role in the transport of angular momentum. Which allows disk material to swirl towards the baby star”, says Lee with excitement. “Our detection of the spirals is an important milestone in understanding the feeding process of baby stars.”

    Spirals detected in protoplanetary disks around somewhat older stars seem to be produced by interaction with unseen baby planets. Unlike those, the spirals here are induced by accretion of material from the surrounding molecular cloud onto the disk.

    The protostar with its disk lies at the center of HH 111, a pair of supersonic jets emerging from a molecular cloud core located 1300 lightyears away in the constellation Orion. The protostar is about half a million years old, just one ten-thousandth the age of our Sun, and has a mass 50% greater than our Sun. A portion of the flow through the disk onto the budding star is diverted to form the spectacular jets. Previous observations with a resolution of 120 AU (An astronomical unit – AU – is the average distance from the Earth to the Sun) detected the accretion disk orbiting the protostar out to a radius of 160 AU. The new observations with ALMA have a resolution of 16 AU, almost eight times better. With this outstanding capability, astronomers were able to resolve the disk spatially. They detected a pair of spiral arms by the glow of thermal emission from dust particles concentrated there (Figure 1).

    The team’s observations open up the exciting possibility of detecting spiral structures in the accretion disks around protostars through high-resolution and high-sensitivity imaging with ALMA, which allows studying accretion disk feeding processes in depth. Such observations also provide insight into accretion disks around other kinds of astrophysical objects, including the supermassive black holes found at the center of active galaxies.

    2
    (Top) Optical image of the jet in the HH 111 protostellar system taken by the Hubble Space Telescope (Reipurth et al. 1999). (Bottom left) Accretion disk detected with ALMA in dust continuum emission at 850 micron. (Bottom middle) The disk turned (de-projected) to be face-on, showing a pair of faint spirals. (Bottom right) Annularly averaged continuum emission is subtracted to highlight the faint spirals in the disk. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al.

    The team is composed of Chin-Fei Lee (ASIAA, Taiwan; National Taiwan University, Taiwan), Zhi-Yun Li (University of Virginia, USA), and Neal J. Turner (JPL/Caltech, USA).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
  • richardmitnick 4:13 pm on October 9, 2019 Permalink | Reply
    Tags: "Rarest form of CO Provides Hint to the Birth of Planets around Young Star", , , , , , Millimeter/submillimeter astronomy, ,   

    From ALMA: “Rarest form of CO Provides Hint to the Birth of Planets around Young Star” 

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

    From ALMA

    Astronomers have discovered the rarest stable carbon monoxide isotope molecule, 13C17O, in the dust and gas disk around a young star using ALMA for the first time. The observations indicate that the disk is more massive than previous estimates, and they may provide an important key to solve mysteries about the planet formation processes in disks.

    1
    Images of 13C17O line emission (green), 12C16O line emission (blue), and dust continuum emission (red and blue) Credit; ALMA (ESO/NAOJ/NRAO), University of Leeds

    The young star, named HD 163296, is located 330 light-years away in the constellation Sagittarius. It is surrounded by a disk of dust and gas – a so-called protoplanetary disk, in which young planets are forming. This disk has multiple ring and gap patterns which are thought to be sub-structures induced by new-born large planets. (https://alma-telescope.jp/en/news/dsharp-201812)

    Using the Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama Desert, Chile, researchers detected an extremely faint signal showing the existence of 13C17O, a rare carbon monoxide isotopologue, that is to say a molecule containing one or more isotopes.

    The detection has allowed scientists to measure the mass of the gas in the disk more accurately than before. The results show that the disk is much heavier – or more ‘massive’ – than previously thought.

    2
    An artist’s impression of planets forming in the ring of gas and dust surrounding a star. Credit; ESO/ L. Calçada

    Alice Booth, a PhD student in the School of Physics and Astronomy, University of Leeds who led the study [The Astrophysical Journal Letters], said: “Our new observations showed there was between two and six times more mass hiding in the disk than previous observations could measure. This is an important finding in terms of the birth of planetary systems in disks – if they contain more gas, then they have more building material to form more massive planets.”

    The research team members are:
    Alice S. Booth (University of Leeds), Catherine Walsh (University of Leeds), John D. Ilee (University of Leeds), Shota Notsu (Leiden University/Kyoto University), Chunhua Qi (Harvard-Smithsonian Center for Astrophysics), Hideko Nomura (National Astronomical Observatory of Japan/Tokyo Institute of Technology), Eiji Akiyama (Hokkaido University)

    This group’s conclusions are well timed. Recent observations of protoplanetary disks have perplexed astronomers because the disks did not seem to contain enough gas and dust to create the planets observed.

    Dr. John Ilee, a researcher at University of Leeds who was also involved in the study, added: “The disk-exoplanet mass discrepancy raises serious questions about how and when planets are formed. However, if other disks are hiding similar amounts of mass as HD 163296, then we may just have underestimated their masses until now.”

    Disk gas masses are usually estimated by observing common forms of carbon monoxide (CO). This molecule is the most useful to determine disk gas mass, since it is abundant and is much easier to observe in cold disks than hydrogen molecules. However the fact that CO is abundant can also become a problem. If the disks are sufficiently dense, however, then the outermost CO molecules start to block part of the emissions from CO molecules deeper within the disk – and that could result in scientists underestimating the total mass of the gas.

    In this study, the scientists targeted the much rarer 13C17O molecule. Because it is rarer, there is less self-blocking, so that the observers could peer deeper inside the disk and find previously hidden gas.

    The scientists expect that using ALMA, they can observe this rare form of CO in many other disks. Dr. Shota Notsu, a JSPS Overseas Research Fellow in Leiden Observatory, Leiden University who was also involved in this study, said: “Measuring the accurate disk masses is key to understand processes of planet formation. Future studies using the rarest forms of CO will enable us to measure the missing mass in many more protoplanetary disks and determine their planet-forming potential.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
  • richardmitnick 10:02 am on October 4, 2019 Permalink | Reply
    Tags: "Food for young twin stars", , , , , , , Millimeter/submillimeter astronomy,   

    From Max Planck Institute for Extraterrestrial Physics: “Food for young twin stars” 

    From Max Planck Institute for Extraterrestrial Physics

    October 03, 2019
    Dr. Hannelore Hämmerle
    Press Officer Max Planck Institute for Extraterrestrial Physics,
    Garching,Germany
    +49 89 30000-3980
    hannelore.haemmerle@mpe.mpg.de

    Dr. Felipe Alves
    Max Planck Institute for Extraterrestrial Physics,
    Garching, Germany
    +49 89 30000-3897
    falves@mpe.mpg.de

    Stars are born in the midst of large clouds of gas and dust. Local densifications first form “embryos”, which then collect matter and grow. But how exactly does this process, called “accretion”, work? And what happens when two stars form in a disk of matter? High-resolution images of a young stellar binary system for the first time reveal a complex network of accretion filaments nurturing two proto-stars at the centre of the circum-binary disk. With these observations, an international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics was able to identify a two-level accretion process, circum-binary disk to circumstellar disk to stars, constraining the conditions leading to the formation and evolution of binary star systems.

    1
    Cosmic delivery room: This picture shows Barnard 59, part of a vast dark cloud of interstellar dust called the Pipe Nebula. The proto-binary systems [BHB2007] 11 studied with high-resolution images is embedded in dense clouds, but can be observed at longer wavelengths with the radio telescope ALMA (Atacama Large Millimeter/submillimeter Array). © ESO

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

    Most stars in the universe come in the form of pairs – binaries – or even multiple star systems. Now, the formation of such a binary star system has been observed for the first time with high-resolution ALMA (Atacama Large Millimetre/submillimetre Array) images. An international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics targeted the system [BHB2007] 11, the youngest member of a small cluster of young stellar objects in the Barnard 59 core in the Pipe nebula molecular cloud. While previous observations showed an accretion envelope surrounding a circum-binary disk, the new observations now also reveal its inner structure.

    “We see two compact sources, that we interpret as circum-stellar disks around the two young stars,” explains Felipe Alves from MPE, who led the study. “The size of each of these disks is similar to the asteroid belt in our Solar System, and their mutual distance is about 28 times the distance between the Earth and the Sun.” Both proto-stars are surrounded by a circum-binary disk with a total mass of about 80 Jupiter masses, which shows a complex network of dust structures distributed in spiral shapes. The shape of the filaments suggest streamers of in-falling material, which is confirmed by the observation of molecular emission lines.

    2
    A zoom into the shared disk: this observation of ALMA shows that the proto-binary system [BHB2007] 11 is surrounded by dust filaments, where the southern (brighter) young star accretes more material. © MPE

    “This is a really important result,” stresses Paola Caselli, director and MPE and head of the Centre of Astrochemical Studies. “We have finally imaged the complex structure of young binary stars, with their “feeding filaments” connecting them to the circum-binary disk. This provides important constraints for current models of star formation.”

    The astronomers interpret the filaments as inflow streamers from the extended circum-binary disk, where the circum-stellar disk around the less massive of the two proto-stars receives more input, consistent with theoretical predictions. The estimated accretion rate is only about 0.01 Jupiter masses per year, which agrees with rates estimated for other proto-stellar systems. In a similar way as the circum-binary disk feeds the circum-stellar disks, each circum-stellar disk feeds the proto-star in its centre. At the disk-star level though, the accretion rate inferred from the observations is higher for the more massive object. The observation of emission from an extended radio jet for the northern object confirms this result, which is an independent indication that this proto-star is indeed accreting more material.

    “We expect this two-level accretion process to drive the dynamics of the binary system during its mass accretion phase,” states Alves. “While the good agreement of these observations with theory is already very promising, we will need to study more young binary systems in detail to further constrain the conditions that lead to stellar multiplicity.”

    Original publication:
    Gas flow and accretion via spiral streamers and circumstellar disks in a young binary protostar
    Science

    The team is composed of F. O. Alves (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany), P. Caselli (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Germany), J. M. Girart (Institut de Ciències de l’Espai, Consejo Superior de Investigaciones Científicas, Spain and Institut d’Estudis Espacials de Catalunya, Spain), D. Segura-Cox (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany), G. A. P. Franco (Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil), A. Schmiedeke (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany) and B. Zhao (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    For their astrophysical research, the MPE scientists measure the radiation of far away objects in different wavelenths areas: from millimetere/sub-millimetre and infared all the way to X-ray and gamma-ray wavelengths. These methods span more than twelve decades of the electromagnetic spectrum.

    The research topics pursued at MPE range from the physics of cosmic plasmas and of stars to the physics and chemistry of interstellar matter, from star formation and nucleosynthesis to extragalactic astrophysics and cosmology. The interaction with observers and experimentalists in the institute not only leads to better consolidated efforts but also helps to identify new, promising research areas early on.

    The structural development of the institute mainly has been directed by the desire to work on cutting-edge experimental, astrophysical topics using instruments developed in-house. This includes individual detectors, spectrometers and cameras but also telescopes and integrated, complete payloads. Therefore the engineering and workshop areas are especially important for the close interlink between scientific and technical aspects.

    The scientific work is done in four major research areas that are supervised by one of the directors:

    Center for Astrochemical Studies (CAS)
    Director: P. Caselli

    High-Energy Astrophysics
    Director: P. Nandra

    Infrared/Submillimeter Astronomy
    Director: R. Genzel

    Optical & Interpretative Astronomy
    Director: R. Bender

    Within these areas scientists lead individual experiments and research projects organised in about 25 project teams.

    The Max Planck Society is Germany’s most successful research organization. Since its establishment in 1948, no fewer than 18 Nobel laureates have emerged from the ranks of its scientists, putting it on a par with the best and most prestigious research institutions worldwide. The more than 15,000 publications each year in internationally renowned scientific journals are proof of the outstanding research work conducted at Max Planck Institutes – and many of those articles are among the most-cited publications in the relevant field.

    What is the basis of this success? The scientific attractiveness of the Max Planck Society is based on its understanding of research: Max Planck Institutes are built up solely around the world’s leading researchers. They themselves define their research subjects and are given the best working conditions, as well as free reign in selecting their staff. This is the core of the Harnack principle, which dates back to Adolph von Harnack, the first president of the Kaiser Wilhelm Society, which was established in 1911. This principle has been successfully applied for nearly one hundred years. The Max Planck Society continues the tradition of its predecessor institution with this structural principle of the person-centered research organization.

    The currently 83 Max Planck Institutes and facilities conduct basic research in the service of the general public in the natural sciences, life sciences, social sciences, and the humanities. Max Planck Institutes focus on research fields that are particularly innovative, or that are especially demanding in terms of funding or time requirements. And their research spectrum is continually evolving: new institutes are established to find answers to seminal, forward-looking scientific questions, while others are closed when, for example, their research field has been widely established at universities. This continuous renewal preserves the scope the Max Planck Society needs to react quickly to pioneering scientific developments.

     
  • richardmitnick 12:38 pm on August 22, 2019 Permalink | Reply
    Tags: , , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “ALMA Shows What’s Inside Jupiter’s Storms” 

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

    From ALMA

    22 August, 2019

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Cell phone: +1 (434) 249 3423
    Email: alma-pr@nrao.edu

    1
    Radio image of Jupiter made with ALMA. Bright bands indicate high temperatures and dark bands low temperatures. The dark bands correspond to the zones on Jupiter, which are often white at visible wavelengths. The bright bands correspond to the brown belts on the planet. This image contains over 10 hours of data, so fine details are smeared by the planet’s rotation. Credit: ALMA (ESO/NAOJ/NRAO), I. de Pater et al.; NRAO/AUI NSF, S. Dagnello

    Swirling clouds, big colorful belts, giant storms. The beautiful and incredibly turbulent atmosphere of Jupiter has been showcased many times. But what is going on below the clouds? What is causing the many storms and eruptions that we see on the ‘surface’ of the planet? However, to study this, visible light is not enough. We need to study Jupiter using radio waves.

    New radio wave images made with the Atacama Large Millimeter/submillimeter Array (ALMA) provide a unique view of Jupiter’s atmosphere down to fifty kilometers below the planet’s visible (ammonia) cloud deck.

    “ALMA enabled us to make a three-dimensional map of the distribution of ammonia gas below the clouds. And for the first time, we were able to study the atmosphere below the ammonia cloud layers after an energetic eruption on Jupiter,” said Imke de Pater of the University of California, Berkeley (EE. UU.).

    The atmosphere of giant Jupiter is made out of mostly hydrogen and helium, together with trace gases of methane, ammonia, hydrosulfide, and water. The top-most cloud layer is made up of ammonia ice. Below that is a layer of solid ammonia hydrosulfide particles, and deeper still, around 80 kilometers below the upper cloud deck, there likely is a layer of liquid water. The upper clouds form the distinctive brown belts and white zones seen from Earth.

    Many of the storms on Jupiter take place inside those belts. They can be compared to thunderstorms on Earth and are often associated with lightning events. Storms reveal themselves in visible light as small bright clouds, referred to as plumes. These plume eruptions can cause a major disruption of the belt, which can be visible for months or years.

    The ALMA images were taken a few days after amateur astronomers observed an eruption in Jupiter’s South Equatorial Belt in January 2017. A small bright white plume was visible first, and then a large-scale disruption in the belt was observed that lasted for weeks after the eruption.

    De Pater and her colleagues used ALMA to study the atmosphere below the plume and the disrupted belt at radio wavelengths and compared these to UV-visible light and infrared images made with other telescopes at approximately the same time.

    “Our ALMA observations are the first to show that high concentrations of ammonia gas are brought up during an energetic eruption,” said de Pater. “The combination of observations simultaneously at many different wavelengths enabled us to examine the eruption in detail. Wich led us to confirm the current theory that energetic plumes are triggered by moist convection at the base of water clouds, which are located deep in the atmosphere. The plumes bring up ammonia gas from deep in the atmosphere to high altitudes, well above the main ammonia cloud deck,” she added.

    “These ALMA maps at millimeter wavelengths complement the maps made with the National Science Foundation’s Very Large Array in centimeter wavelengths,” said Bryan Butler of the National Radio Astronomy Observatory.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    “Both maps probe below the cloud layers seen at optical wavelengths and show ammonia-rich gases rising into and forming the upper cloud layers (zones), and ammonia-poor air sinking down (belts).”

    “The present results show superbly what can be achieved in planetary science when an object is studied with various observatories and at various wavelengths”. Explains Eric Villard, an ALMA astronomer part of the research team. “ALMA, with its unprecedented sensitivity and spectral resolution at radio wavelengths, worked together successfully with other major observatories around the world, to provide the data to allow a better understanding of the atmosphere of Jupiter.”

    3
    Flat map of Jupiter in radio waves with ALMA (top) and visible light with the Hubble Space Telescope (bottom). The eruption in the South Equatorial Belt is visible in both images. Credit: ALMA (ESO/NAOJ/NRAO), I. de Pater et al.; NRAO/AUI NSF, S. Dagnello; NASA/Hubble

    Science paper:
    First ALMA Millimeter Wavelength Maps of Jupiter, with a Multi-Wavelength Study of Convection
    https://arxiv.org/pdf/1907.11820.pdf

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
  • richardmitnick 12:29 pm on August 7, 2019 Permalink | Reply
    Tags: "ALMA Identified Dark Ancestors of Massive Elliptical Galaxies", , , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “ALMA Identified Dark Ancestors of Massive Elliptical Galaxies” 

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

    From ALMA

    7 August, 2019

    Tao Wang
    Postdoctoral fellow
    Institute of Astronomy, The University of Tokyo / National Astronomical Observatory of Japan
    Email: taowang@ioa.s.u-tokyo.ac.jp

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Calum Turner
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: calum.turner@eso.org

    Mariya Lyubenova
    ESO Outreach Astronomer
    Garching bei München, Germany
    Phone: +49 89 32 00 61 88
    Email: mlyubeno@eso.org

    Iris Nijman
    Public Information Officer
    National Radio Astronomy Observatory Charlottesville, Virginia – USA
    Cell phone: +1 (434) 249 3423
    Email: alma-pr@nrao.edu

    1
    An artistic representation of the distant galaxies observed with ALMA. ALMA identified faint galaxies invisible to the Hubble Space Telescope. For the research team, these galaxies precede the massive elliptical galaxies of the present Universe. Credits: NAOJ

    Astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to identify 39 faint galaxies that are not seen with the Hubble Space Telescope’s most in-depth view of the Universe, 10 billion light-years away. They are ten times more numerous than similarly massive but optically–bright galaxies detected with Hubble. The research team assumes that these faint galaxies precede massive elliptical galaxies in the present Universe. However, no significant theories for the evolution of the Universe have predicted such an abundant population of star-forming, dark, massive galaxies. The new ALMA results throw into question our understanding of the early Universe. These results appear in the latest issue of the journal Nature.

    “Previous studies have found extremely active star-forming galaxies in the early Universe, but their population is quite limited,” says Tao Wang, lead author of this research at the University of Tokyo, the French Alternative Energies and Atomic Energy Commission (CEA), and the National Astronomical Observatory of Japan (NAOJ). “Star formation in the dark galaxies we identified is less intense, but they are 100 times more abundant than the extreme starbursts. It is important to study such a major component of the history of the Universe to comprehend galaxy formation.”

    Wang and his team targeted three ALMA windows to the deep Universe opened up by the Hubble Space Telescope (HST): the CANDELS fields. The team discovered 63 extremely red objects in the infrared images taken by NASA’s Spitzer Space Telescope: they are too red to be detected with HST. However, Spitzer’s limited spatial resolution prevented astronomers from identifying their nature.

    ALMA detected submillimeter-wave emission from 39 out of the 63 extremely red objects. Thanks to its high resolution and sensitivity, ALMA confirmed that they are massive, star-forming galaxies that are producing stars 100 times more efficiently than the Milky Way. These galaxies are representative of the majority of massive galaxies in the Universe 10 billion years ago, most of which have so far been missed by previous studies.

    “By maintaining this rate of star formation, these ALMA-detected galaxies will likely transform into the first population of massive elliptical galaxies formed in the early Universe,” says David Elbaz, an astronomer at CEA, and coauthor on the paper, “But there is a problem. They are unexpectedly abundant.” The researchers estimated their number density to be equivalent to 530 objects in a square degree in the sky. This number density well exceeds predictions from current theoretical models and computer simulations. Also, according to the widely accepted model of the Universe with a particular type of dark matter, it is challenging to build a large number of massive objects in such an early phase of the Universe. Together, the present ALMA results challenge our current understanding of the evolution of the Universe.

    “Like the galaxy Messier 87, from which astronomers recently obtained the first-ever image of a black hole, massive elliptical galaxies are located in the heart of galaxy clusters.

    The first image of a black hole, Messier 87 Credit Event Horizon Telescope Collaboration, via NSF and ERC 4.10.19

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

    Scientist believes that these galaxies formed most of their stars in the early Universe,” explains Kotaro Kohno, a professor at the University of Tokyo and member of the research team. “However, previous searches for the progenitors of these massive galaxies have been unsuccessful because they were based solely on galaxies that are easily detectable by HST. The discovery of this large number of massive, HST-dark galaxies provides direct evidence for the early assembly of massive galaxies during the first billion years of the Universe.” More detailed follow-up observations with ALMA and NASA’s James Webb Space Telescope are essential to provide further insights into the nature of these galaxies. New studies could enable a complete view of galaxy formation in the early Universe.”

    2
    ALMA identified 39 faint galaxies that are not seen with the Hubble Space Telescope’s most in-depth view of the Universe 10 billion light-years away. This example image shows a comparison of Hubble and ALMA observations. The squares numbered from 1 to 4 are the locations of faint galaxies unseen in the Hubble image. Credit: The University of Tokyo/CEA/NAOJ.

    The research team members are:
    T. Wang (The University of Tokyo/CEA/National Astronomical Observatory of Japan), C. Schreiber (CEA/Leiden University/Oxford University), D. Elbaz (CEA), Y. Yoshimura (The University of Tokyo), K. Kohno (The University of Tokyo), X. Shu (Anhui Normal University), Y. Yamaguchi (The University of Tokyo), M. Pannella (Ludwig-Maximilians-Universitat,), M. Franco (CEA), J. Huang (National Astronomical Observatories of China), C.-F. Lim (Academia Sinica Institute of Astronomy and Astrophysics), and W.-H. Wang (Academia Sinica Institute of Astronomy and Astrophysics).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
  • richardmitnick 8:51 am on June 21, 2019 Permalink | Reply
    Tags: , , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “Planetary Rings of Uranus Glow in Cold Light” 

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

    From ALMA

    20 June, 2019

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Calum Turner
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: calum.turner@eso.org

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

    1
    Artist impression of the planet Uranus and its dark ring system. Rather than observing the reflected sunlight from these rings, astronomers have imaged the millimeter and mid-infrared “glow” naturally emitted by the frigidly cold particles of the rings themselves. Credit: NRAO/AUI/NSF; S. Dagnello

    Using the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Telescope (VLT), astronomers have imaged the cold, rock-strewn rings encircling the planet Uranus. Rather than observing the reflected sunlight from these rings, ALMA and the VLT imaged the millimeter and mid-infrared glow naturally emitted by the frigidly cold particles of the rings themselves. Only discovered in 1977, Uranus rings are invisible to most but the largest telescopes. However, they are surprisingly bright in the thermal images from ALMA and VLT.

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    The thermal glow gives astronomers another window onto the rings, which only have been seen because they reflect a little light from the Sun. The new images taken by ALMA and the VLT allowed the team for the first time to measure the temperature of the rings: a cool 77º Kelvin, or 77º degrees above absolute zero; equivalent to -196.15º Celsius.

    The observations also confirm that Epsilon, Uranus’s brightest and densest ring, differs from the other known rings within our solar system, in particular, the spectacularly beautiful rings of Saturn, that “are broad, bright and have a range of particle sizes, from micron-sized dust in the innermost D ring to tens of meters in size in the main rings,” said Imke de Pater, a UC Berkeley professor of astronomy. “The small end is missing in the main rings of Uranus; the brightest ring, epsilon, is composed of golf ball-sized and larger rocks.”

    By comparison, Jupiter’s rings contain mostly small, micron-sized particles (a micron is a thousandth of a millimeter). Neptune’s rings are also mostly dust, and even Uranus has broadsheets of dust between its narrow main rings.

    “We already know that the Epsilon ring is a bit weird because we don’t see the smaller stuff,” said Edward Molter, a graduate student from the same university. “Something has been sweeping the smaller stuff out, or it’s all glomming together. We just don’t know. This is a step to further understanding their composition and whether all of the rings came from the same source material or are different for each one.”

    Rings could be former asteroids captured by the planet’s gravity, remnants of moons that crashed into one another and shattered, the remains of moons torn apart when they got too close to Uranus, or debris remaining from the formation 4.5 billion years ago.

    The new data was published this week in The Astronomical Journal. De Pater and Molter led the ALMA observations, while Michael Roman and Leigh Fletcher from the University of Leicester, U.K., led the VLT observations.

    “The rings of Uranus are compositionally different from Saturn’s main ring, in the sense that in optical and infrared, the albedo, thus the reflectance capacity, is much lower: they are really dark, like charcoal,” Molter said. “They are also extremely narrow compared to the rings of Saturn. The widest of them, Epsilon, varies from 20 to 100 kilometers wide, whereas Saturn’s are hundreds or tens of thousands of kilometers wide.”

    The lack of dust-sized particles in Uranus’s main rings was first noted when Voyager 2 flew by the planet in 1986, however, the spacecraft was unable to measure the temperature of the rings. To date, astronomers have counted a total of 13 rings around the planet, with some bands of dust between the rings.

    “It’s cool that we can even do this with the instruments we have,” Molter said. “I was just trying to image the planet as best I could, and I saw the rings. It was amazing.”

    Both the VLT and ALMA observations were designed to explore the temperature structure of Uranus’ atmosphere, with VLT probing shorter wavelengths than ALMA.

    “We were astonished to see the rings jump out clearly when we reduced the data for the first time,” Fletcher said.

    This presents an exciting opportunity for the upcoming James Webb Space Telescope, which will be able to provide vastly improved details on the Uranian rings once launched in the coming decade.

    The research team was composed by Edward M. Molter [1], Imke de Pater [1], Michael T. Roman [2], and Leigh N. Fletcher [2].

    [1] Astronomy Department, University of California, Berkeley; Berkeley CA, 94720, USA.
    [2] Department of Physics & Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, UK.

    2
    Composite image of Uranus’s atmosphere and rings at radio wavelengths, taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in December 2017. The image shows thermal emission, or heat, from the rings of Uranus for the first time, enabling scientists to determine their temperature is a frigid 77 K (-320 F). Dark bands in Uranus’s atmosphere at these wavelengths show the presence of radiolight-absorbing molecules, in particular hydrogen sulfide (H2S) gas, whereas bright regions like the north polar spot contain very few of these molecules. Credit: ALMA (ESO/NAOJ/NRAO); E. Molter and I. de Pater.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
  • richardmitnick 3:24 pm on June 17, 2019 Permalink | Reply
    Tags: , ALMA Finds Earliest Example of Merging Galaxies, , , , , Millimeter/submillimeter astronomy,   

    From ALMA: “ALMA Finds Earliest Example of Merging Galaxies” 

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

    From ALMA

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu
    Education and Public Outreach Officer, NAOJ Chile
    Observatory
, Tokyo – Japan
    Phone: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    Calum Turner
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Phone: +49 89 3200 6670
    Email: calum.turner@eso.org

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

    17 June, 2019

    1
    Composite image of B14-65666 showing the distributions of dust (red), oxygen (green), and carbon (blue), observed by ALMA and stars (white) observed by the Hubble Space Telescope. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Hashimoto et al.

    Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) observed the earliest combined signals of oxygen, carbon, and dust from a galaxy in the Universe, 13 billion years ago. By comparing the different signals, the team determined that the galaxy is, in fact, two merging galaxies, making it the earliest example of merging galaxies yet discovered.

    Takuya Hashimoto at Waseda University, Japan, and his team used ALMA to observe B14-65666, an object located 13 billion light-years away in the constellation Sextans. Because of the finite speed of light, the signals we receive from B14-65666 today had to travel for 13 billion years to reach us. In other words, they show us the image of what the galaxy looked like 13 billion years ago, less than 1 billion years after the Big Bang.

    ALMA achieved the earliest observation of radio emissions from oxygen, carbon, and dust in B14-65666. The detection of multiple signals allows astronomers to retrieve complementary information.

    Data analysis showed that the emissions are divided into two blobs. Previous observations with the Hubble Space Telescope (HST) had revealed two-star clusters in B14-65666. Now, with the three emission signals detected by ALMA, the team was able to show that the two blobs do in-fact form a single system, but with different speeds; which indicates that the blobs are two merging galaxies. The earliest known example of merging galaxies. The research team estimated that the total stellar mass of B14-65666 is less than 10% that of the Milky Way, meaning that it’s in its earliest phases of evolution. Despite its youth, B14-65666 is producing stars 100 times more actively than the Milky Way. Such active star-formation rate is another signature of galactic mergers because the gas compression in colliding galaxies naturally leads to bursty star-formation.

    “With rich data from ALMA and HST, combined with advanced data analysis, we could put the pieces together to show that B14-65666 is a pair of merging galaxies in the earliest era of the Universe,” explains Hashimoto. “Detection of radio waves from three components in such a distant object demonstrates ALMA’s high capability to investigate the distant Universe.”

    Present galaxies like our Milky Way have experienced countless, often violent, mergers. Sometimes a more massive galaxy swallowed a smaller one. In rare cases, galaxies with similar sizes merged to form a new, larger galaxy. Mergers are essential for galaxy evolution, attracting many astronomers eager to trace back them.

    “Our next step is to search for nitrogen, another major chemical element, and even the carbon monoxide molecule,” said Akio Inoue, a professor at Waseda University. “Ultimately, we hope to observationally understand the circulation and accumulation of elements and material in the context of galaxy formation and evolution.”

    These observation results were published as T. Hashimoto et al. “’Big Three Dragons’: a z = 7.15 Lyman Break Galaxy Detected in [OIII] 88 um, [CII] 158 um, and Dust Continuum with ALMA” in the Publications of the Astronomical Society of Japan on June 18, 2019.

    The research team members are: Takuya Hashimoto (Waseda University/Osaka Sangyo University/National Astronomical Observatory of Japan), Akio Inoue (Waseda University/Osaka Sangyo University), Ken Mawatari (Osaka Sangyo University/The University of Tokyo), Yoichi Tamura (Nagoya University), Hiroshi Matsuo (National Astronomical Observatory of Japan/SOKENDAI), Hisanori Furusawa (National Astronomical Observatory of Japan), Yuichi Harikane (The University of Tokyo), Takatoshi Shibuya (Kitami Institute of Technology), Kirsten K. Knudsen (Chalmers University of Technology), Kotaro Kohno (The University of Tokyo), Yoshiaki Ono (The University of Tokyo), Erik Zackrisson (Uppsala University), Takashi Okamoto (Hokkaido University), Nobunari Kashikawa (National Astronomical Observatory of Japan/SOKENDAI/ The University of Tokyo), Pascal A. Oesch (University of Geneva), Masami Ouchi (The University of Tokyo/National Astronomical Observatory of Japan), Kazuaki Ota (Kyoto University), Ikkoh Shimizu (Osaka University), Yoshiaki Taniguchi (The Open University of Japan), Hideki Umehata (The Open University of Japan/RIKEN), Darach Watson (University of Copenhagen).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 10:58 am on June 15, 2019 Permalink | Reply
    Tags: , , , , , Millimeter/submillimeter astronomy, New ALMA Image Reveals Migrating Planet in Protoplanetary Disk   

    From ALMA: “New ALMA Image Reveals Migrating Planet in Protoplanetary Disk” 

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

    From ALMA

    Nicolás Lira
    Education and Public Outreach Coordinator
    Joint ALMA Observatory, Santiago – Chile
    Phone: +56 2 2467 6519
    Cell phone: +56 9 9445 7726
    Email: nicolas.lira@alma.cl

    1
    ALMA observation of HD169142 which shows an outer region composed of thin rings and a double gap. These fine structures had never seen before in the outer parts of a disk with a deep chasm which severs the protoplanetary environment into inner and outer regions. On the other hand, the ALMA high-resolution image also reveals a bright inner ring with signs of being subject to dynamical perturbations. Solar system size approximated by Pluto’s orbit is shown for comparison. Credit: N. Lira – ALMA (ESO/NAOJ/NRAO); S. Pérez – USACH/UChile.

    2
    Comparison between ALMA image and theoretical simulation of the protoplanetary disk in HD169142. Simulated image of a planet with ten times the mass of Earth, sculpting the outer regions of a protoplanetary disk. The fine rings are composed of dust particles which are trapped into concentric structures by pressure waves excited during the interaction between the planet and the disk. Credit: N. Lira – ALMA (ESO/NAOJ/NRAO); S. Pérez – USACH/UChile.

    3
    Labelled ALMA image describing the structure of the protoplanetary disk in HD169142. Credit: N. Lira – ALMA (ESO/NAOJ/NRAO); S. Pérez – USACH/UChile.

    A new high-resolution image from the Atacama Large Millimeter/submillimeter Array (ALMA) features a protoplanetary disk with an isolated outer region composed of an intricate system of thin rings and gaps, instead of the wide and smooth ring expected for these disks. The isolation of this never seen before structures allowed a research team to explain it with a straightforward interpretation: a single, migrating planet ten times the mass of Earth sculpting the dust particles into multiple narrow rings.

    Finding direct connections between the gaps seen in protoplanetary disks and the properties of planets opens a new window to investigate a population of young planets that are exceedingly difficult to detect with any other method.

    ALMA has seen a plethora of rings and gaps in almost all protoplanetary disks it has observed at high resolution, yet the origins of these structures remain a matter of intense debate. As the quality of the observations increases, the ringed structures grow in number and complexity, challenging a simple interpretation based on planetary origins. The new ALMA observations of HD169142, a protoplanetary disk 370 light-years away in the constellation of Sagittarius, allowed a team led by Sebastian Perez, from University of Santiago (Chile) to explain the seemingly complex architecture of protoplanetary ring systems with the presence of a single low-mass planet.

    Even though it was designed to avoid disks with evidence of deep gaps and holes, the DSHARP ALMA Large Program unveiled, less than a year ago, several new ring systems. In the absence of a clear gap that separates an outer region, the superposition of multiple rings due to several planets hampers simple and clear explanations such as that found for HD169142. This particular ring system thus allows a proof of concept to interpret the detailed architecture of the outer region of protoplanetary disks, with low mass planet formation of mini-Neptune’s size. The fact that the middle ring is closer to the inner ring is the first evidence for planetary migration in disk observations. The planet moves closer to the star, shrinking its orbit, while shepherding the middle ring with it.

    “The high-fidelity of ALMA helped us reveal unexpected substructure in the outer ring of a system thought to have no narrow rings” explains Sebastian Pérez, from Universidad de Santiago, and lead author of this research. “The community has made great progress on interpreting these sharp rings seen in young planetary systems. Here, one small planet interacting with tiny dust particles can reproduce these rings in isolation, revealing its properties in an indirect way. This one and other similar experiments open new possibilities of characterization of super young extra-solar planets.”

    Science paper:
    Dust Unveils the Formation of a Mini-Neptune Planet in a Protoplanetary Ring
    [The Astronomical Journal]

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The 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 Large

     
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