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  • richardmitnick 9:59 pm on September 16, 2014 Permalink | Reply
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    From ALMA: “Violent Origins of Pancake Galaxies Probed by ALMA” 

    ESO ALMA Array
    ALMA

    Wednesday, 17 September 2014

    Contacts

    Junko Ueda
    JSPS postdoctoral fellow/NAOJ
    Tel: +88 422 34 3117
    Email: junko.ueda@nao.ac.jp

    Lars Lindberg Christensen
    Head of ESO ePOD
    Garching bei München, Germany
    Tel: +49 89 3200 6761
    Cell: +49 173 3872 621
    Email: lars@eso.org

    Masaaki Hiramatsu
    NAOJ Chile Observatory EPO officer
    Tel: +88 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

    New observations explain why Milky Way-like galaxies are so common in the Universe

    For decades scientists have believed that galaxy mergers usually result in the formation of elliptical galaxies. Now, for the the first time, researchers using ALMA and a host of other radio telescopes have found direct evidence that merging galaxies can instead form disc galaxies, and that this outcome is in fact quite common. This surprising result could explain why there are so many spiral galaxies like the Milky Way in the Universe.

    bunch
    Distribution of gas in merging galaxies observed by radio telescopes. Contours indicate the radio intensity emitted from CO gas. The colour shows the motion of gas. The red color indicates gas is moving away from us while the blue colour is coming closer to us. The gradation from red to blue means that gas is rotating in a disc-like manner around the centre of the galaxy. | Credit: ALMA (ESO/NAOJ/NRAO)/SMA/CARMA/IRAM/J. Ueda et al

    disc
    Example of disc galaxy, The Sculptor Galaxy (NGC 253)
    Atlas Image [or Atlas Image mosaic] courtesy of 2MASS/UMass/IPAC-Caltech/NASA/http://www.nsf.gov/

    An international research group led by Junko Ueda, a Japan Society for the Promotion of Science postdoctoral fellow, has made surprising observations that most galaxy collisions in the nearby Universe — within 40–600 million light-years from Earth — result in so-called disc galaxies. Disc galaxies — including spiral galaxies like the Milky Way and lenticular galaxies — are defined by pancake-shaped regions of dust and gas, and are distinct from the category of elliptical galaxies.

    It has, for some time, been widely accepted that merging disc galaxies would eventually form an elliptically shaped galaxy. During these violent interactions the galaxies do not only gain mass as they merge or cannibalise each-other, but they are also changing their shape throughout cosmic time, and therefore changing type along the way.

    Computer simulations from the 1970s predicted that mergers between two comparable disc galaxies would result in an elliptical galaxy. The simulations predict that most galaxies today are elliptical, clashing with observations that over 70% of galaxies are in fact disc galaxies. However, more recent simulations have suggested that collisions could also form disc galaxies.

    To identify the final shapes of galaxies after mergers observationally, the group studied the distribution of gas in 37 galaxies that are in their final stages of merging. The Atacama Large Millimeter/sub-millimeter Array (ALMA) and several other radio telescopes were used to observe emission from carbon monoxide (CO), an indicator of molecular gas.

    The team’s research is the largest study of molecular gas in galaxies to date and provides unique insight into how the Milky Way might have formed. Their study revealed that almost all of the mergers show pancake-shaped areas of molecular gas, and hence are disc galaxies in the making. Ueda explains: “For the first time there is observational evidence for merging galaxies that could result in disc galaxies. This is a large and unexpected step towards understanding the mystery of the birth of disc galaxies.”

    Nonetheless, there is a lot more to discover. Ueda added: “We have to start focusing on the formation of stars in these gas discs. Furthermore, we need to look farther out in the more distant Universe. We know that the majority of galaxies in the more distant Universe also have discs. We however do not yet know whether galaxy mergers are also responsible for these, or whether they are formed by cold gas gradually falling into the galaxy. Maybe we have found a general mechanism that applies throughout the history of the Universe.”

    The team is composed of Junko Ueda (JSPS postdoctoral fellow/National Astronomical Observatory of Japan [NAOJ]), Daisuke Iono (NAOJ/The Graduate University for Advanced Studies [SOKENDAI]), Min S. Yun (The University of Massachusetts), Alison F. Crocker (The University of Toledo), Desika Narayanan (Haverford College), Shinya Komugi (Kogakuin University/ NAOJ), Daniel Espada (NAOJ/SOKENDAI/Joint ALMA Observatory), Bunyo Hatsukade (NAOJ), Hiroyuki Kaneko (University of Tsukuba), Yoichi Tamura (The University of Tokyo), David J. Wilner (Harvard-Smithsonian Center for Astrophysics), Ryohei Kawabe (NAOJ/ SOKENDAI/The University of Tokyo) and Hsi-An Pan (Hokkaido University/SOKENDAI/NAOJ)

    The data were obtained by ALMA, the Combined Array for Research in Millimeter-wave Astronomy: a millimeter array consisting of 23 parabola antennas in California, the Submillimeter Array a submillimeter array consisting of eight parabola antennas in Mauna Kea, Hawaii, and the Plateau de Bure Interferometer, the NAOJ Nobeyama Radio Observatory 45m radio telescope, USA’s National Radio Astronomy Observatory 12m telescope, USA’s Five College Radio Astronomy Observatory 14m telescope, IRAM’s 30m telescope, and the Swedish-ESO Submillimeter Telescope as a supplement.

    carma
    CARMA Array

    Submillimeter Array Hawaii SAO
    SAO Submillimeter Array on Mauna Kea

    IRAM Interferometer Submillimeter Array of Radio Telescopes
    IRAM Interferometer

    naoj
    NAOJ Nobeyama Radio Observatory 45m radio telescope

    aro
    ARO KP12M Radio Telescope

    IRAM 30m Radio telescope
    IRAM 30m Radio Telescope

    ESO
    Swedish-ESO Submillimeter Telescope

    See the full article, with notes, here.

    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 6:53 pm on September 10, 2014 Permalink | Reply
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    From ALMA: “ALMA Achieves New High Frequency Observing Capabilities: Shows Planet Uranus in New Light” 

    ESO ALMA Array
    ALMA

    Wednesday, 10 September 2014
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

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

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

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

    The Atacama Large Millimeter/submillimeter Array (ALMA) has reached a major milestone by extending its vision fully into the realm of the submillimeter, the wavelengths of cosmic light that hold intriguing information about the cold, dark, and distant Universe.

    Uranus
    ALMA high frecuencies image of Uranus

    This achievement opens an entirely new window on the Universe for ALMA and goes beyond its existing capabilities with the Band 9 receivers. It also is a critical step in the telescope’s commissioning process, which brings its full capabilities to bear and makes them available to the international astronomical community.

    As a demonstration of its new capabilities, the commissioning team released a new image of planet Uranus as it appears in submillimeter wavelength light. The image ― obtained with ALMA’s highest frequency, Band 10 receivers ― reveals the icy glow from the planet’s atmosphere, which is a frigid -224 degrees Celsius (making Uranus the coldest planet in the Solar System). ALMA’s now broader range of capabilities will enable astronomers and planetary scientists to study and monitor changes in the atmosphere of Uranus and other distant objects in our Solar System in ways that were previously not possible.

    cold
    The cold atmosphere of Uranus imaged with the ALMA band 10 receivers | Neil Phillips (ESO/JAO) and Ed Fomalont (NRAO)

    JAO astronomer Satoko Takahashi of the National Astronomical Observatory of Japan who lead this effort said: “Before astronomers could take advantage of the highest frequencies, we first had to take the telescope through its paces and establish observing strategies that yield the best, most accurate results. That’s why commissioning is so critical to our success”.

    ALMA observes the cosmos by using a series of precisely tuned receivers that are installed on each of the array’s 66 antennas. Each receiver type is sensitive to a particular “band”, or range of wavelengths, of the electromagnetic spectrum. The highest frequency Band 10 receivers have already been installed and tested on a majority of the ALMA antennas and the remainder will be installed and integrated over the next several months.

    band 10
    ALMA band 10 receiver cartridge | NAOJ

    To take full advantage of ALMA’s new high-frequency capabilities, the commissioning team is in the process of refining two new observing techniques. The first, “band to band transfer,” enables ALMA to observe at high frequencies in less than optimal weather conditions by first observing an object at longer wavelengths, and then using that data to calibrate, or “tune,” the telescope for a particular observation. “This technique will greatly expand the amount of time ALMA can effectively study the Universe at higher frequencies”, added Violette Impellizzeri, JAO astronomer with the National Radio Astronomy Observatory.

    Another technique involves first observing at very broadband wavelengths and then tuning-in to more narrowband, shorter wavelengths. This technique will soon be routine operating procedure, even though it is unique to ALMA at these wavelengths. Combined, these two techniques open up many more hours of observations at shorter wavelengths than would otherwise be possible

    Teams from around the world are still on their way to ALMA to further verify these techniques and provide the optimal observing strategy for observing with ALMA at high frequencies.

    More Information

    The international commissioning team for the High Frequency Observing Campaign was led by Satoko Takasashi of the National Astronomical Observatory of Japan, ALMA’s representative East Asia and Anthony Remijan of the National Radio Astronomy Observatory and the ALMA Program Scientist for Extension and Optimization of Capabilities. Other members include Catherine Vlahakis, Neil Philips, Denis Barkats, Bill Dent (JAO/ESO), Ed Fomalont, Brian Mason, Jennifer Donovan Meyer (NRAO); Violette Impellizzeri, Paulo Cortes, Christian Lopez (JAO/NRAO); Christine Wilson (NRAO/McMaster University); Seiji Kameno, Tsyuoshi Sawada (JAO/NAOJ); Tim Van Kempen, Luke Maud & Remo Tilanus (Leiden); Robert Lucas (Grenoble); Richard Hills (Cambridge); James Chibueze, Akihiko Hirota (JAO/NAOJ).

    See the full article here.

    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 3:42 pm on August 25, 2014 Permalink | Reply
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    From ESO: “New ALMA Equipment Designed in Chile” 


    European Southern Observatory

    25 August 2014
    Richard Hook
    ESO, Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    ALMA Array
    ALMA Array

    New equipment for transporting one of the most sensitive components of the ALMA array — the antenna Front Ends (cryogenic refrigerators) — has been delivered to ALMA by the National Radio Astronomy Observatory (NRAO), the North American associate of the Atacama Large Millimeter/submillimeter Array. This new vehicle, which will save lots of time and increase safety during manoeuvers, was completely designed and built in Chile. It is the first shipment of one of four vehicles for handling the Front Ends that hold the set of detectors inside ALMA´s antennas, and is part of the technological exchange policy with the host country.

    set3

    The Front End Handling Vehicle (FEHV) — a robust elevator-crane car — is the result of a three year design and manufacturing collaboration between NRAO and a team of Chilean professionals from the Prolaser and Maestranza Walper companies, located in the city of Valdivia in the south of Chile. The main tourist attractions of this region inspired the names of each of these four vehicles, being the first one called after a river: Calle-Calle.

    The FEHV will help to shorten the time needed to set up and remove the receivers from the antennas. “This replacement job takes place every five days. Over the 30 year lifetime projected for the observatory using this vehicle will save a huge amount of resources, considering that this specific task takes 2000 person hours a year, approximately”, proudly stated Rodrigo Brito, team leader supervising the official shipment of the manufacturing contribution from the North American partner of ALMA.

    Each cryostat, together with the receivers comprising each Front End, costs about one million dollars, weighs around 750 kilogrammes and must be lifted up almost two metres to be positioned precisely in the confined space inside the antennas cubicles. The FEHV has a built-in platform to lift its load in a safe way, move it and rotate it for perfect alignment during the setup. It weighs 709 kilogrammes and is 2.20 metres long, 1.05 metres wide and 1.50 metres tall.

    See the full article here.

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    ESO, European Southern Observatory, builds and operates a suite of the world’s most advanced ground-based astronomical telescopes.

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  • richardmitnick 1:26 pm on August 20, 2014 Permalink | Reply
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    From ALMA: “ALMA Progress” 

    ESO ALMA Array
    ALMA

    20 August 2014
    Al Wootten

    The ALMA antenna array has moved to configuration C34-6 – 3mm beam 0.6 arcsec, baselines 41-1090m – with the acceptance of key distant antenna stations; earlier observations in configuration C34-5, which includes baselines of 20-900m, were obtained. Observations requiring C34-7 will be made after the next austral summer. Beginning in September, several antennas will be moved to more distant stations to enable tests on baselines of 10km. Early Science will be suspended as key capabilities are readied for the ALMA Cycle 3 Call for Proposals, which will occur in austral autumn 2015.

    Recent weather at Chajnantor has been very good, as is usual for the austral winter. From 1-7 August the precipitable water vapor remained below 1mm, and the resulting excellent high frequency transparency benefitted the high frequency campaign. Multiple objectives were met, including the imaging of Uranus with 29 array elements at ALMA Band 10 (350 microns, 810 GHz) by the Joint ALMA Observatory (JAO) Extension and Optimization of Capabilities (EOC) team. The EOC team also demonstrated the transfer of phase information from lower frequencies, where calibrators are brighter and more densely distributed, to higher frequencies and solved problems with total power observations. Simultaneous sub-arraying within the main 12m array was demonstrated for the first time, a key goal for achieving simultaneous EOC and Early Science operations. On Tuesday, 29 July, the ALMA Phasing Project team, with support from EOC, the ALMA Department of Engineering, and the ALMA Department of Computing integrated the new hydrogen maser into the ALMA system.

    maser
    Hydrogen maser. (Courtesy NASA/JPL-Caltech)

    This is an important milestone toward incorporating ALMA as a Very Long Baseline Interferometry array element. Tests have shown the maser performance is excellent, and it has replaced the rubidium clock as the ALMA time standard.

    ALMA Cycle 2 Early Science began on 3 June, and eight one-week blocks have been completed. Current JAO operations allocate a week every two weeks to extending observational capabilities; three such one-week sessions were complete as of publication.

    Nine ALMA Cycle 2 datasets has been delivered to North American (NA) PIs. During July, one new Cycle 2 Director’s Discretionary Time (DDT) project was received and reviewed. Carryover Cycle 1 projects continue to be observed with a priority below that of highest-ranked Cycle 2 projects; two-thirds of the highest-ranked NA Cycle 1 Projects have seen deliveries of some data. Data have been delivered for 2 DDT projects and ten partially observed filler projects. All Cycle 0 data have been delivered. A total of 109 of the 116 Cycle 0 projects are available in the ALMA Science Archive; only a few projects are still in their proprietary period. Ninety-one scientific papers based on these Cycle 0 projects have been published to date.

    See the full article here.

    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 10:45 pm on August 19, 2014 Permalink | Reply
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    From ALMA: “South Korea Sign Agreement on ALMA “ 

    ESO ALMA Array
    ALMA

    Tuesday, 19 August 2014
    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

    On August 17, 2014, the National Institutes of Natural Sciences (NINS) and Korea Astronomy and Space Science Institute (KASI) signed an agreement concerning the operations and development of ALMA. With this agreement, Korea officially joined in the East Asia ALMA consortium whose current members are Japan and Taiwan.

    people
    The picture shows the attendees of the signing ceremony (from left): Chul-Sung Choi (Director of Space Science Division, KASI), Jongsoo Kim (Director of Radio Astronomy Division, KASI), Youngdeuk Park (Vice President of KASI), Katsuhiko Sato (President of NINS), Inwoo Han (President of KASI), Masahiko Hayashi (Director General of NAOJ), Hideyuki Kobayashi (Deputy Director of NAOJ), Satoru Iguchi (East Asia ALMA Project Manager, NAOJ) Credit: Korea Astronomy and Space Science Institute (KASI)

    Japan and Korea have promoted active collaboration in the field of astronomy. In 2001, the two countries made a successful VLBI observation for the first time by linking the 45-m radio telescope of the Nobeyama Radio Observatory (NRO) of the National Observatory of Japan (NAOJ) and the 14-m radio telescope of the Taeduk Radio Astronomy Observatory of Korea. The following year, NAOJ and KASI officially signed an agreement to further strengthen the collaboration. And a decade later, in March 2012, NAOJ and KASI signed a Memorandum of Understanding (MoU) concerning the collaboration of ALMA.

    This agreement enables Korea’s participation into the ALMA project as well as their contribution to the operations of ALMA and development of new instruments. It is expected that this agreement will enhance the cooperation of two countries in astronomy and greatly promote the diversity and innovativeness of East Asian astronomical researches.

    See the full article here.

    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 3:24 pm on August 5, 2014 Permalink | Reply
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    From NRAO: “ALMA Pinpoints Pluto to Help Guide NASA’s New Horizons Spacecraft” 

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    August 5, 2014
    Charles Blue, NRAO Public Information Officer
    (434) 296-0314; cblue@nrao.edu

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) are making high-precision measurements of Pluto’s location and orbit around the Sun to help NASA’s New Horizons spacecraft accurately home in on its target when it nears Pluto and its five known moons in July 2015.

    ALMA Array
    ALMA

    NASA New Horizons spacecraft
    NASA/New Horizons

    Though observed for decades with ever-larger optical telescopes on Earth and in space, astronomers are still working out Pluto’s exact position and path around our Solar System. This lingering uncertainty is due to Pluto’s extreme distance from the Sun (approximately 40 times farther out than the Earth) and the fact that we have been studying it for only about one-third of its orbit. Pluto was discovered in 1930 and takes 248 years to complete one revolution around the Sun.

    “With these limited observational data, our knowledge of Pluto’s position could be wrong by several thousand kilometers, which compromises our ability to calculate efficient targeting maneuvers for the New Horizons spacecraft,” said New Horizons Project Scientist Hal Weaver, from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

    The New Horizons team made use of the ALMA positioning data, together with newly analyzed visible light measurements stretching back to Pluto’s discovery, to determine how to perform the first such scheduled course correction for targeting, known as a Trajectory Correction Maneuver (TCM), in July. This maneuver helped ensure that New Horizons uses the minimum fuel to reach Pluto, saving as much as possible for a potential extended mission to explore Kuiper Belt objects after the Pluto system flyby is complete.

    kuiper
    Kuiper Belt

    To prepare for this first TCM, astronomers needed to pinpoint Pluto’s position using the most distant and most stable reference points possible. Finding such a reference point to accurately calculate trajectories of such small objects at such vast distances is incredibly challenging. Normally, stars at great distances are used by optical telescopes for astrometry (the positioning of things on the sky) since they change position only slightly over many years. For New Horizons, however, even more precise measurements were necessary to ensure its encounter with Pluto would be as on-target as possible.

    The most distant and most apparently stable objects in the Universe are quasars, galaxies more than 10 billion light-years away. Though quasars appear very dim to optical telescopes, they are incredibly bright at radio wavelengths, particularly the millimeter wavelengths that ALMA can see.

    “The ALMA astrometry used a bright quasar named J1911-2006 with the goal to cut in half the uncertainty of Pluto’s position,” said Ed Fomalont, an astronomer with the National Radio Astronomy Observatory in Charlottesville, Virginia, and currently assigned to ALMA’s Operations Support Facility in Chile.

    ALMA was able to study Pluto and its largest moon Charon by picking up the radio emission from their cold surfaces, which are about 43 degrees Kelvin (-230 degrees Celsius).

    The team first observed these two icy worlds in November 2013, and then three more times in 2014 — once in April and twice in July. Additional observations are scheduled for October 2014.

    “By taking multiple observations at different dates, we allow Earth to move along its orbit, offering different vantage points in relation to the Sun,” said Fomalont. “Astronomers can then better determine Pluto’s distance and orbit.” This astronomical technique is called measuring Pluto’s parallax.

    “We are very excited about the state-of-the-art capabilities that ALMA brings to bear to help us better target our historic exploration of the Pluto system,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado. “We thank the entire ALMA team for their support and for the beautiful data they are gathering for New Horizons.”

    The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

    ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by the European Southern Observatory (ESO), on behalf of North America by the National Radio Astronomy Observatory (NRAO), 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.

    New Horizons is the first mission to the Pluto system and the Kuiper Belt of rocky, icy objects beyond. The Johns Hopkins University Applied Physics Laboratory (APL) manages the mission for NASA’s Science Mission Directorate; Alan Stern, of the Southwest Research Institute (SwRI), is the principal investigator and leads the mission. SwRI leads the science team, payload operations and encounter science planning; APL designed, built and operates the New Horizons spacecraft. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Ala. For more information, visit http://pluto.jhuapl.edu.

    See the full article here.

    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)*.

    NRAO ALMA
    NRAO ALMA

    NRAO GBT
    NRAO GBT

    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.

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  • richardmitnick 1:35 pm on July 30, 2014 Permalink | Reply
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    From ALMA: “ALMA Finds Double Star with Weird and Wild Planet-forming Discs” 

    ESO ALMA Array
    ALMA

    Wednesday, 30 July 2014

    Eric L. N. Jensen
    Lead Scientist, Swarthmore College
    Philadelphia, USA
    Tel: +1 610-328-8249
    Email: ejensen1@swarthmore.edu

    Rachel Akeson
    NASA Exoplanet Science Institute, IPAC/Caltech
    Pasadena, USA
    Tel: +1 626-395-1812
    Email: rla@ipac.caltech.edu

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

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

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

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

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have found wildly misaligned planet-forming gas discs around the two young stars in the binary system HK Tauri. These new ALMA observations provide the clearest picture ever of protoplanetary discs in a double star. The new result also helps to explain why so many exoplanets — unlike the planets in the Solar System — came to have strange, eccentric or inclined orbits. The results will appear in the journal Nature on 31 July 2014.

    Unlike our solitary Sun, most stars form in binary pairs — two stars that orbit around each other. Though remarkably plentiful, binaries pose a number of questions, including how and where planets form in such complex environments.

    two
    Fig. 1 Artist’s impression of the misaligned protoplanetary disks around the binary stars in HK Tau. Credit: R. Hurt (NASA/JPL-Caltech/IPAC)

    “ALMA has given us an unprecedented view of a main star and its binary companion sporting mutually misaligned protoplanetary disks,” said Eric Jensen, an astronomer at Swarthmore College in Pennsylvania, USA.

    The two stars in the HK Tauri system, which is located about 450 light-years from Earth in the constellation Taurus, are less than 5 million years old and separated by about 58 billion kilometers, or 13 times the distance of Neptune from the Sun.

    This system’s companion star, dubbed HK Tau B, appears fainter to astronomers on Earth because its disk of dust and gas blocks out much of the starlight. However, since its faint glow is swamped by the dazzling brightness of the star, the disc can be readily detected in visible light and near-infrared wavelengths.

    two2
    Fig. 2: ALMA data of HK Tau shown in a composite image with Hubble infrared and optical data. Credit: B. Saxton (NRAO/AUI/NSF); K. Stapelfeldt et al. (NASA/ESA Hubble)

    The disk around the main star, HK Tau A, is tilted in such a way that the light from its host star shines through unobscured, making it difficult for astronomers to see the disk optically. This is not a problem for ALMA, however, which can readily detect the millimeter-wavelength light emitted by the dust and gas that comprise the disk.

    With its unprecedented resolution and sensitivity, ALMA was able to fully resolve the rotation of HK Tau A’s disk for the first time. This clearer picture enabled the astronomers to calculate that the two discs are out of alignment with each other by at least 60 degrees. So rather than being in the same plane as the orbits of the two stars at least one of the discs must be significantly misaligned.

    “This clear misalignment has given us a remarkable look at a young binary star system,” said Rachel Akeson of the NASA Exoplanet Science Institute at the California Institute of Technology in Pasadena, California. “Though there have been hints before that this type of misaligned system exists, this is the cleanest and most striking example of what is really going on in one of these systems.”

    four
    Fig. 3: The key velocity data taken with ALMA that helped the astronomers determine that the disks in HK Tau were misaligned. The red areas represent material moving away from Earth and the blue indicates material moving toward us. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

    Stars and planets form out of vast clouds of dust and gas. As material in these clouds contracts under gravity, it begins to rotate until most of the dust and gas falls into a flattened protoplanetary disk swirling around a growing central protostar.

    But in binary systems like HK Tauri things are much more complex. When the orbits of the stars and the protoplanetary discs are not roughly in the same plane any planets may end up in highly eccentric and tilted orbits.

    Our results demonstrate that the necessary conditions exist to modify planetary orbits and that these conditions are present at the time of planet formation, apparently due to the binary formation process,” noted Jensen. “We can’t rule other theories out, but we can certainly rule in that a second star will do the job.”

    Since ALMA can see the otherwise invisible dust and gas of protoplanetary disks, it allowed for never-before-seen views of this young binary system. “Because we’re seeing this in the early stages of formation with the protoplanetary disks still in place, we can see better how things are oriented,” noted Akeson.

    Looking forward, the researchers want to determine if this type of system is typical or not. They note that this is a remarkable individual case, but additional surveys are needed to determine if this sort of arrangement is common throughout our Galaxy.


    Fly-in animation of HK Tau and its pair of misalgned planet-forming disks. Credit: Brian Kent, Bill Saxton, Jeff Hellerman (NRAO/AUI/NSF); NASA/JPL-Caltech/R. Hurt (IPAC); NASA/ESA Hubble Karl Stapelfeldt (JPL) et al.

    See the full article, with note, and video, here.

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

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

    NRAO Small

    ESO 50

    NAOJ


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  • richardmitnick 3:21 pm on July 17, 2014 Permalink | Reply
    Tags: ALMA, , , , , ,   

    From NRAO: “ALMA Upgrade to Supercharge Event Horizon Telescope, Astronomy’s ‘Killer App’” 

    NRAO Icon

    National Radio Astronomy Observatory

    NRAO Banner

    June 4, 2014

    Contact: Charles Blue
    cblue@nrao.edu
    (434) 296-0314

    Scientists recently upgraded the Atacama Large Millimeter/submillimeter Array (ALMA) by installing an ultraprecise atomic clock at ALMA’s Array Operations Site, home to the observatory’s supercomputing correlator. This upgrade will eventually allow ALMA to synchronize with a worldwide network of radio astronomy facilities collectively known as the Event Horizon Telescope (EHT).

    Once assembled, the EHT — with ALMA as the largest and most sensitive site — will form an Earth-sized telescope with the magnifying power required to see details at the edge of the supermassive black hole at the center of the Milky Way.

    ALMA Array
    Before ALMA can lend its unmatched capabilities to this and similar scientific observations, however, it must first transform into a different kind of instrument known as a phased array. This new version of ALMA will allow its 66 antennas to function as a single radio dish 85 meters in diameter. It’s this unified power coupled with ultraprecise timekeeping that will allow ALMA to link with other observatories.

    A major milestone along this path was achieved recently when the science team performed what could be considered a “heart transplant” on the telescope by installing a custom-built atomic clock powered by a hydrogen maser. This new timepiece uses a process similar to a laser to amplify a single pure tone, cycles of which are counted to produce a highly accurate ‘tick’.

    ALMA’s original time reference, a clock based on rubidium gas, will be retired and used as a spare after the maser is completely integrated with ALMA’s electronics.

    Shep Doeleman, the principal investigator of the ALMA Phasing Project and assistant director of the Massachusetts Institute of Technology’s Haystack Observatory, participated during the maser installation via remote video link. “Once the phasing is complete, ALMA will use the ultraprecise ticking of this new atomic clock to join the aptly named Event Horizon Telescope as the most sensitive participating site, increasing sensitivity by a factor of 10,” he said.

    Expanding the Frontiers of Astronomy

    Supermassive black holes lurk at the center of all galaxies and contain millions or even billions of times the mass of our Sun. These space-bending behemoths are so massive that nothing, not even light, can escape their gravitational influence. Understanding how a black hole devours matter, powers jets of particles and energy, and distorts space and time are leading challenges in astronomy and physics.

    The black hole at the center of the Milky Way is a 4 million solar mass giant located approximately 26,000 light-years from Earth in the direction of the constellation Sagittarius. It is shrouded from optical telescopes by dense clouds of dust and gas, which is why observatories like ALMA, which operate at the longer millimeter and submillimeter wavelengths, are essential to study its properties.

    Supermassive black holes can be relatively tranquil or they can flare up and drive incredibly powerful jets of subatomic particles deep into intergalactic space; quasars seen in the very early Universe are an extreme example. The fuel for these jets comes from in-falling material, which becomes superheated as it spirals inward. Astronomers hope to capture our Galaxy’s central black hole in the process of actively feeding to better understand how black holes affect the evolution of our Universe and how they shape the development of stars and galaxies.

    A phased ALMA will arrive just in time to observe a highly anticipated cosmic event, the collision of a giant cloud of dust and gas known as G2 with our Galaxy’s central supermassive black hole. It is speculated that this collision may awaken this sleeping giant, generating extreme energy and possibly fueling a jet of subatomic particles, a highly unusual feature in a mature spiral galaxy like the Milky Way. The collision is predicted to begin in 2014 and will likely continue for more than a year.

    High resolution imaging of the event horizon also could improve our understanding of how the highly ordered Universe as described by [Albert]Einstein meshes with the messy and chaotic cosmos of quantum mechanics – two systems for describing the physical world that are woefully incompatible on the smallest of scales.

    Other independent research will target molecules in space to determine whether or not the fundamental constants of nature have changed over cosmic time.

    Shadowy Science

    The light-bending power of black holes also presents a unique opportunity to observe the so-called “shadow” of a black hole. Light near the event horizon of a black hole does not travel in a straight line, but instead takes on weird hyperbolic trajectories and can even achieve a stable orbit. Some of this light, which begins its journey traveling away from observers on Earth, can get twisted back around, warping in such a way that it takes a 180 degree turn. This would allow scientists to study the far-side of a black hole and actually see its shadow in space. Since the size and shape of this shadow depends on the mass and spin of black hole, these observations could tell us much about how space and time are warped in this extreme environment.

    Calculations indicate a resolution of 50 micro-arcseconds (approximately 2,000 times finer than the Hubble Space Telescope) is needed to image the shadow effect. That’s equivalent to reading the date on a quarter at the distance from New York to Los Angeles. This amazing high-resolution imaging is within the reach of the ALMA-enabled Event Horizon Telescope.

    Development Timeline and Funding

    Initial planning for a Phased ALMA Array began in 2008, propelled by the objective of imaging a black hole and other previously unattainable science. The requirements necessary to phase the ALMA array were shared early on with the ALMA design team so the implementation plan would not affect ALMA construction or operations.

    The Phased ALMA Array is funded primarily by the U.S. National Science Foundation. Additional funding is provided through North American contributions to the ALMA Development Fund and international cost sharing through the Academia Sinica Institute of Astronomy and Astrophysics, Max Planck Institute for Radio Astronomy, Universidad de Concepcion, the Japan Society for the Promotion of Science, and the Toray Science Foundation. Initial funding was provided in 2011. The project passed preliminary design review and was approved by the ALMA Board in 2012. The project passed Critical Design Review in 2013.

    The current goal is to test the first combined signal of a phased ALMA and another telescope in 2014, and to undergo full commissioning and be ready for full observations in 2015.

    Technology and Engineering

    ALMA was designed to work as an interferometer – a telescope made up of many individual elements. Each antenna pair creates a single baseline. ALMA can produce as many as 1,291 baselines, some up to 16 kilometers long.

    The phased array, however, operates differently. The signals from all the antennas are simply added together. To do this, specialized electronics and computer equipment are being built at the National Radio Astronomy Observatory’s Central Development Lab in Charlottesville, Virginia. These new circuit boards will be installed into ALMA’s correlator, the supercomputer that combines the signals from the antennas.

    The signal from the phased array will then be time-stamped and encoded by a dedicated atomic clock – the new hydrogen maser procured and tested by MIT’s Haystack Observatory — which will allow the data to be shipped to a central processing center where it will be combined with identically timed signals from other telescopes.

    The high-speed recorders that will capture the torrent of data flowing from the ALMA phased array were designed by the MIT Haystack Observatory. Software to run the new phasing system is being developed by multiple institutions involved in the phasing project.

    Event Horizon Telescope

    The Event Horizon Telescope (EHT) derives its extreme magnifying power from connecting widely spaced radio dishes across the globe into an Earth-sized virtual telescope. This technique, called Very Long Baseline Interferometry (VLBI), is the same process that enables telescopes like the NRAO’s Very Long Baseline Array (VLBA) to achieve such amazing power and resolution. The difference between existing VLBI facilities and the EHT is the sheer geographical scope of the EHT project, its extension to the shortest observing wavelengths, and addition of the unprecedented collecting area enabled by a phased ALMA.

    “By uniting the most advanced millimeter and submillimeter wavelength radio dishes across the globe, the Event Horizon Telescope creates a fundamentally new instrument with the greatest magnifying power ever achieved,” said Doeleman. “Anchored by ALMA, the EHT will open a new window onto black hole research and bring into focus one of the only places in the Universe where Einstein’s theories may break down: at the event horizon.”

    ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), 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.

    The U.S. National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering.

    See the full article here.

    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)*.

    NRAO ALMA
    NRAO ALMA

    NRAO GBT
    NRAO GBT

    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.


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  • richardmitnick 6:00 am on July 13, 2014 Permalink | Reply
    Tags: ALMA, , , , ,   

    From ALMA: “Dynamical Star-Forming Gas Interaction Witnessed by ALMA” 

    ESO ALMA Array
    ALMA

    Thursday, 03 July 2014
    Toshikazu Onishi
    Professor, Osaka Prefecture University
    Tel: +81- 72-254-9727
    Email: ohnishi@p.s.osakafu-u.ac.jp

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

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

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

    Richard Hook
    Public Information Officer, ESO
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591

    Dynamical interaction of star-forming gas was found in a star-forming region by observations with the Atacama Large Millimeter/submillimeter Array (ALMA). This is a remarkable observation result that disproves a conventional assumption that stars are formed by slow contraction of gas clouds.

    image

    A research team led by Kazuki Tokuda and Toshikazu Onishi at Osaka Prefecture University conducted ALMA observations of a high-density gas cloud called MC27/L1521F in the constellation Taurus. From past observation results, it was confirmed that MC27 has a new-born star. And by this observation the research team found a new starless high-density core, which is considered to be very close to the initial stage of star formation, right next to the new-born star. Also, the research team detected an extended gas cloud around MC27 which is assumed to be formed by dynamic gravitational interaction of two or more gas cores. Such dynamical kinematics of star formation which was newly found by this observation will be a key factor in understanding star formation process starting from gas clouds.

    Stars are formed in molecular cloud cores composed of dust and gas which have several solar masses within 0.1 light years. It has already been known that a protostar (baby star) is formed at the center of the molecular cloud cores with increased density of gas and dust, but the distribution of gas and dust around a protostar, or their distribution and kinematics at the birth of a protostar have not yet been well understood.

    To detect a clue to these mysteries, it is necessary to conduct detailed investigation of the environment surrounding a newborn protostar soon after birth or to observe high-density molecular cloud cores at the earliest phase of protostar formation. The research team led by Kazuki Tokuda, a graduate student at Osaka Prefecture University, and Toshikazu Onishi, a professor at the same university, conducted ALMA observations of a molecular cloud core MC27 (about 450 light years away from the Earth in the direction of the constellation Taurus, the Bull) which contains a newborn protostar. By past observations with the Nobeyama Radio Observatory (NRO) 45-m Telescope of the National Astronomical Observatory of Japan (NAOJ), it was found that MC27 is a very high-density molecular cloud core. Also NASA’s Spitzer Space Telescope discovered a very low-luminosity protostar deep inside the high-density molecular cloud core. The research team carried out detailed observations of dust continuum emission at the center of MC27 and molecular lines of HCO+ from high-density gas to study the properties of gas and dust shortly after the birth of a protostar using ALMA that has high sensitivity and high resolution.

    Nobeyama Solar Radio Telescope Array
    Nobeyama

    NASA Spitzer Telescope
    NASA/Spitzer

    The obtained results were far beyond the researcher’s expectations. They found that that the center of MC27 contains not only gas surrounding the protostar but also two high-density gas condensations (Figure 1). One of the gas condensations MMS-2 at a distance of 200 au from the protostar is the highest-density molecular cloud core (with tens of millions of gas molecules within 1 cubic centimeter) ever found in low-mass star forming regions. The research team presumes that MMS-2 is at a stage very close to the birth of a protostar.

    image 1
    Fig. 1: A false-color composite image: ALMA observations of dust continuum emission (green) and high-density gas emission (red), and Spitzer observation of infrared emission (blue). While the infrared image shows only the central protostar, ALMA observation results show high-density molecular cloud cores and an extended gas cloud. Credit: Kazuki Tokuda (Osaka Prefecture University) / ALMA(ESO/NAOJ/NRAO) / NASA / JPL-Caltech

    A newborn protostar is surrounded by a large amount of gas and dust, which are pulled toward the growing protostar by gravity. Since the interstellar matter around the protostars is absorbed into the protostar or blown away within hundreds of thousands of years after the birth of a protostar, it is not easy to probe the conditions of gas and dust at the birth of a protostar. Kazuki Tokuda says, “It was very exciting when we found a star-forming gas condensation right next to the protostar. We might say we are witnessing star-forming gas at the very moment of birth of a star. We will study further and gain better understanding of star formation mechanism.”

    Another finding of this observation is an outflow of gas from the protostar. This outflow is smaller than the outflows ever observed around other protostars. From its dimensions and velocity, the outflow from the protostar is supposed to have occurred from several decades to 200 years ago, which indicates that the protostar is very young. ALMA captured the site where a newborn star just after birth and an “egg of a star” are growing together.

    A further surprising result is the existence of an extended gas cloud which looks like a tail of MMS-2. The length of the cloud reaches 200 au and its velocity is somewhat different from that of the molecular cloud core. Shu-ichiro Inutsuka, a professor at Nagoya University and one of the research collaborators, says, “This long-shaped structure is supposed to be formed by strong gravitational interaction between fast-moving molecular cloud cores.” In physics, “turbulence” indicates a state of gas flow where gas moves around chaotically. When a swirling turbulence occurs, gas clouds are broken apart into smaller clouds. These reshaped small gas clouds are constantly on the move while pulling each other by gravity and their influence ripples across the surrounding environment in a wave-like formation and makes an extended gas structure which looks like a bow.

    The research team assumes the extended gas structure found in MC27 would be associated with such dynamic gas movement as described. Tomoaki Matsumoto, a professor at Hosei University and a member of the research team, did computer simulations of gas clouds where strong turbulence is taking place. As a result of the study, it was found that small gas clouds could form stars inside them while revolving around each other and evolve into a multiple star system with multiple orbits around each other. The obtained results can be interpreted as an initial phase of multiple star formation process.

    Toshikazu Onishi, a member of the research team says, “We first obtained observational data of MMS-2, an extended gas cloud, and a gas outflow at a very early stage by using ALMA. These results will greatly contribute to the establishment of multiple star formation theory. We expect that further detailed observations of MC27 and future ALMA observations of other molecular cloud cores will bring rapid progress in understanding of the star formation mechanism and its process.”

    The research team members are: Kazuki Tokuda (Graduate student at Osaka Prefecture University) Toshikazu Onishi (Professor at Osaka Prefecture University) Kazuya Saigo (Project assistant professor at the National Astronomical Observatory of Japan) Akiko Kawamura (Project associate professor at the National Astronomical Observatory of Japan) Yasuo Fukui (Professor at Nagoya University) Tomoaki Matsumoto (Professor at Hosei University) Shu-ichiro Inutsuka (Professot at Nagoya University) Masahiro Machida (Associate professor at Kyushu University) Kengo Tomida (Research Fellow of the Japan Society for the Promotion of Science, Princeton University/the University of Tokyo) Kengo Tachihara (Associate professor at Nagoya University)

    This research was supported by the Japan Society of the Promotion of Science (JSPS) grants (22244014, 23403001, 23540270).

    See the full article, with notes, here.

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

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

    NRAO Small

    ESO 50

    NAOJ


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  • richardmitnick 5:02 am on July 3, 2014 Permalink | Reply
    Tags: ALMA, , , ,   

    From ALMA: “Dynamical Star-Forming Gas Interaction Witnessed by ALMA” 

    ESO ALMA Array
    ALMA

    Thursday, 03 July 2014
    Toshikazu Onishi
    Professor, Osaka Prefecture University
    Tel: +81- 72-254-9727
    Email: ohnishi@p.s.osakafu-u.ac.jp

    Valeria Foncea
    Education and Public Outreach Officer
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 467 6258
    Cell: +56 9 75871963
    Email: vfoncea@alma.cl

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

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

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

    Dynamical interaction of star-forming gas was found in a star-forming region by observations with the Atacama Large Millimeter/submillimeter Array (ALMA). This is a remarkable observation result that disproves a conventional assumption that stars are formed by slow contraction of gas clouds.

    gas
    Fig. 1: A false-color composite image: ALMA observations of dust continuum emission (green) and high-density gas emission (red), and Spitzer observation of infrared emission (blue). While the infrared image shows only the central protostar, ALMA observation results show high-density molecular cloud cores and an extended gas cloud. Credit: Kazuki Tokuda (Osaka Prefecture University) / ALMA(ESO/NAOJ/NRAO) / NASA / JPL-Caltech

    A research team led by Kazuki Tokuda and Toshikazu Onishi at Osaka Prefecture University conducted ALMA observations of a high-density gas cloud called MC27/L1521F in the constellation Taurus. From past observation results, it was confirmed that MC27 has a new-born star. And by this observation the research team found a new starless high-density core, which is considered to be very close to the initial stage of star formation, right next to the new-born star. Also, the research team detected an extended gas cloud around MC27 which is assumed to be formed by dynamic gravitational interaction of two or more gas cores. Such dynamical kinematics of star formation which was newly found by this observation will be a key factor in understanding star formation process starting from gas clouds.

    Stars are formed in molecular cloud cores composed of dust and gas which have several solar masses within 0.1 light years. It has already been known that a protostar (baby star) is formed at the center of the molecular cloud cores with increased density of gas and dust, but the distribution of gas and dust around a protostar, or their distribution and kinematics at the birth of a protostar have not yet been well understood.

    To detect a clue to these mysteries, it is necessary to conduct detailed investigation of the environment surrounding a newborn protostar soon after birth or to observe high-density molecular cloud cores at the earliest phase of protostar formation. The research team led by Kazuki Tokuda, a graduate student at Osaka Prefecture University, and Toshikazu Onishi, a professor at the same university, conducted ALMA observations of a molecular cloud core MC27 (about 450 light years away from the Earth in the direction of the constellation Taurus, the Bull) which contains a newborn protostar. By past observations with the Nobeyama Radio Observatory (NRO) 45-m Telescope of the National Astronomical Observatory of Japan (NAOJ), it was found that MC27 is a very high-density molecular cloud core. Also NASA’s Spitzer Space Telescope discovered a very low-luminosity protostar deep inside the high-density molecular cloud core. The research team carried out detailed observations of dust continuum emission at the center of MC27 and molecular lines of HCO+ from high-density gas to study the properties of gas and dust shortly after the birth of a protostar using ALMA that has high sensitivity and high resolution.

    NASA Spitzer Telescope
    NASA/Spitzer

    The obtained results were far beyond the researcher’s expectations. They found that that the center of MC27 contains not only gas surrounding the protostar but also two high-density gas condensations (Fig 1). One of the gas condensations MMS-2 at a distance of 200 au from the protostar is the highest-density molecular cloud core (with tens of millions of gas molecules within 1 cubic centimeter) ever found in low-mass star forming regions. The research team presumes that MMS-2 is at a stage very close to the birth of a protostar.

    A newborn protostar is surrounded by a large amount of gas and dust, which are pulled toward the growing protostar by gravity. Since the interstellar matter around the protostars is absorbed into the protostar or blown away within hundreds of thousands of years after the birth of a protostar, it is not easy to probe the conditions of gas and dust at the birth of a protostar. Kazuki Tokuda says, “It was very exciting when we found a star-forming gas condensation right next to the protostar. We might say we are witnessing star-forming gas at the very moment of birth of a star. We will study further and gain better understanding of star formation mechanism.”

    Another finding of this observation is an outflow of gas from the protostar. This outflow is smaller than the outflows ever observed around other protostars. From its dimensions and velocity, the outflow from the protostar is supposed to have occurred from several decades to 200 years ago, which indicates that the protostar is very young. ALMA captured the site where a newborn star just after birth and an “egg of a star” are growing together.

    A further surprising result is the existence of an extended gas cloud which looks like a tail of MMS-2. The length of the cloud reaches 200 au and its velocity is somewhat different from that of the molecular cloud core. Shu-ichiro Inutsuka, a professor at Nagoya University and one of the research collaborators, says, “This long-shaped structure is supposed to be formed by strong gravitational interaction between fast-moving molecular cloud cores.” In physics, “turbulence” indicates a state of gas flow where gas moves around chaotically. When a swirling turbulence occurs, gas clouds are broken apart into smaller clouds. These reshaped small gas clouds are constantly on the move while pulling each other by gravity and their influence ripples across the surrounding environment in a wave-like formation and makes an extended gas structure which looks like a bow.

    The research team assumes the extended gas structure found in MC27 would be associated with such dynamic gas movement as described. Tomoaki Matsumoto, a professor at Hosei University and a member of the research team, did computer simulations of gas clouds where strong turbulence is taking place. As a result of the study, it was found that small gas clouds could form stars inside them while revolving around each other and evolve into a multiple star system with multiple orbits around each other. The obtained results can be interpreted as an initial phase of multiple star formation process.

    Toshikazu Onishi, a member of the research team says, “We first obtained observational data of MMS-2, an extended gas cloud, and a gas outflow at a very early stage by using ALMA. These results will greatly contribute to the establishment of multiple star formation theory. We expect that further detailed observations of MC27 and future ALMA observations of other molecular cloud cores will bring rapid progress in understanding of the star formation mechanism and its process.”

    See the full article,with notes, here.

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

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

    NRAO Small

    ESO 50

    NAOJ


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