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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    Notes

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

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

    Additional information

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

    The research team members are:

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

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

    See the full article here .

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

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

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  • richardmitnick 4:28 pm on December 1, 2016 Permalink | Reply
    Tags: ALMA, , , II Zw 40, , ,   

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

    UCLA bloc

    UCLA

    December 01, 2016
    Katherine Kornei

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

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

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

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

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

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

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

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

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

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

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

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

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

    See the full article here .

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

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

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

    ALMA Array

    ALMA

    04 November 2016
    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

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

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    1
    Galaxies IC 2163 (left) and NGC 2207 (right) recently grazed past each other, triggering a tsunami of stars and gas in IC 2163 and producing the dazzling eyelid-like features there. ALMA image of carbon monoxide (orange), which revealed motion of the gas in these features, is shown on top of Hubble image (blue) of the galaxy pair. Credit: M. Kaufman; B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble Space Telescope

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

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

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

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

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

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

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

    2
    Dazzling eyelid-like features bursting with stars in galaxy IC 2163 formed from a tsunami of stars triggered by a glancing collision with galaxy NGC 2207 (a potion of its spiral arm is shown on right side of image). ALMA image of carbon monoxide (orange), which revealed motion of the gas in these features, is shown on top of Hubble image (blue) of the galaxy. Credit: M. Kaufman; B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble Space Telescope

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

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

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

    said Kaufman.

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

    3
    Annotated image showing dazzling eyelid-like features bursting with stars in galaxy IC 2163 formed from a tsunami of stars triggered by a glancing collision with galaxy NGC 2207 (a potion of its spiral arm is shown on right side of image). ALMA image of carbon monoxide (orange), which revealed motion of the gas in these features, is shown on top of Hubble image (blue) of the galaxy. Credit: M. Kaufman; B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble Space Telescope

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

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

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

    said Kaufman.

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

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

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

    See the full article here .

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

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

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  • richardmitnick 11:11 am on November 1, 2016 Permalink | Reply
    Tags: ALMA, , ,   

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

    ALMA Array

    ALMA

    1

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

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

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

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  • richardmitnick 2:36 pm on October 26, 2016 Permalink | Reply
    Tags: ALMA, , , L1448 IRS3B system, , , , Young Stellar System Caught in Act of Forming Close Multiples   

    From ALMA: “Young Stellar System Caught in Act of Forming Close Multiples” 

    ALMA Array

    ALMA

    26 October 2016
    Dave Finley
    Public Information Officer
    Karl G. Jansky Very Large Array (VLA)
    Tel: 1 575.835-7302
    Email: dfinley@nrao.edu

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

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

    Tel: +81 422 34 3630

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

    1
    ALMA image of the L1448 IRS3B system, with two young stars at the center and a third distant from them. Spiral structure in the dusty disk surrounding them indicates instability in the disk, astronomers said. Credit: Bill Saxton, ALMA (ESO/NAOJ/NRAO), NRAO/AUI/NSF.

    For the first time, astronomers have seen a dusty disk of material around a young star fragmenting into a multiple-star system. Scientists had suspected such a process, caused by gravitational instability, was at work, but new observations with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Karl G. Jansky Very Large Array (VLA) revealed the process in action.

    NRAO/VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA
    NRAO/VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

    “This new work directly supports the conclusion that there are two mechanisms that produce multiple star systems — fragmentation of circumstellar disks, such as we see here, and fragmentation of the larger cloud of gas and dust from which young stars are formed,” said John Tobin, of the University of Oklahoma and Leiden Observatory in the Netherlands.

    Stars form in giant clouds of gas and dust, when the tenuous material in the clouds collapses gravitationally into denser cores that begin to draw additional material inward. The infalling material forms a rotating disk around the young star. Eventually, the young star gathers enough mass to create the temperatures and pressures at its center that will trigger thermonuclear reactions.

    Previous studies had indicated that multiple star systems tend to have companion stars either relatively close, within about 500 times the Earth-Sun distance, or significantly farther apart, more than 1,000 times that distance. Astronomers concluded that the differences in distance result from different formation mechanisms. The more widely-separated systems, they said, are formed when the larger cloud fragments through turbulence, and recent observations have supported that idea.

    The closer systems were thought to result from fragmentation of the smaller disk surrounding a young protostar, but that conclusion was based principally on the relative proximity of the companion stars.

    2
    Combined ALMA and VLA image of L1448 IRS3B system. Credit: Bill Saxton, ALMA (ESO/NAOJ/NRAO), NRAO/AUI/NSF.

    “Now, we’ve seen this disk fragmentation at work,” Tobin said.

    Tobin, Kaitlin Kratter of the University of Arizona, and their colleagues used ALMA and the VLA to study a young triple-star system called L1448 IRS3B, located in a cloud of gas in the constellation Perseus, some 750 light-years from Earth. The most central of the young stars is separated from the other two by 61 and 183 times the Earth-Sun distance. All three are surrounded by a disk of material that ALMA revealed to have spiral structure, a feature that, the astronomers said, indicates instability in the disk.

    “This whole system probably is less than 150,000 years old.” Kratter said. “Our analysis indicates that the disk is unstable, and the most widely separated of the three protostars may have formed only in the past 10,000 to 20,000 years,” she added.

    3
    Artist’s conception of how the triple-star system develops. Left, disk of material fragments into separate protostars. Right, the resulting stellar system. Credit: Bill Saxton, NRAO/AUI/NSF.

    The L1448 IRS3B system, the astronomers conclude, provides direct observational evidence that fragmentation in the disk can produce young multiple-star systems very early in their development.

    “We now expect to find other examples of this process and hope to learn just how much it contributes to the population of multiple stars,” Tobin said.

    The scientists presented their findings in the October 27 edition of the journal Nature.

    See the full article here .

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

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

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  • richardmitnick 9:34 am on October 20, 2016 Permalink | Reply
    Tags: ALMA, , , , New Webcams for ALMA and Paranal   

    From ESO: “New Webcams for ALMA and Paranal” 

    ESO 50 Large

    European Southern Observatory

    20 October 2016
    Peter Grimley
    ESO Assistant Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6383
    Email: pgrimley@partner.eso.org

    1

    New high-definition cameras have been installed at ESO’s Very Large Telescope (VLT) and at the Atacama Large Millimeter/submillimeter Array (ALMA) . They will provide improved 24/7 interactive views of these two flagship observatories in Chile and will complement ESO’s suite of existing live webcam views..

    The new cameras provide a live 360-degree view of the activities at the observatories throughout the year and can be used interactively to explore the site in all directions in exquisite detail. In addition, there are several high-resolution “points of interest”, which include a dedicated feed of the Cerro Armazones mountain in Chile — the site of the new European Extremely Large Telescope (E-ELT) — to document the construction of the world’s largest optical telescope, scheduled for completion in 2024. Also shown are the operations of the smaller Auxiliary Telescopes at Paranal, and, on very clear days, the Llullaillaco volcano can be seen, at a distance of 190 km on the Chilean border with Argentina. At the ALMA site, antennas from ESO, North America (USA and Canada) and East Asia (Japan, Taiwan, and Republic of Korea) can be appreciated as well as the APEX telescope in the background. Geographical wonders are also visible in these images: the Licancabur stratovolcano and the curious, blade-like snow formations, known as penitentes, that form only at the high altitudes where ALMA is located.

    The cameras are so sensitive that the night sky over Paranal and ALMA can be experienced as one would see it on site. At times the bright yellow laser beams from the VLT’s Adaptive Optics can be seen firing high up into the atmosphere.

    The new cameras also break new ground by providing the world’s first live observatory views: ALMA and Paranal are presented in razor-sharp 4k fish-eye images for use in planetariums around the world, including the upcoming ESO Supernova Planetarium & Visitor Centre in Germany.

    The cameras have been provided by Apical. Based in France, Apical is a high-tech company specialising in innovative solutions for wide-field and high-resolution imaging and for network connectivity in extreme, challenging places.

    See the full article here .

    A separate post from ALMA is here .

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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

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  • richardmitnick 9:05 am on October 13, 2016 Permalink | Reply
    Tags: ALMA, , , Dense molecular gas disks drive the growth of supermassive black holes, ,   

    From ALMA: “Dense molecular gas disks drive the growth of supermassive black holes” 

    ALMA Array

    ALMA

    13 October 2016
    Takuma Izumi
    The University of Tokyo
    Email: takumaizumi@ioa.s.u-tokyo.ac.jp

    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

    1
    A conceptual rendition of gas being driven into a supermassive black hole following a supernova explosion. Strong turbulence caused by supernova explosions inside a dense molecular gas disk in the central region of a galaxy disturbs the stable motion of gas. This causes the gas to flow further inward toward the supermassive black hole at the center. Credit: The University of Tokyo

    A joint team of University of Tokyo researchers and their collaborators, using the Atacama Large Millimeter/submillimeter Array (ALMA) and other telescopes that utilize radio waves for space observation, revealed that dense molecular gas disks a few hundred light-years in scale located at the centers of galaxies supply gas to supermassive black holes situated within them. This finding provides important insights on the growth of supermassive black holes over cosmic time.

    Supermassive black holes more than a million times the mass of our sun exist at the centers of many galaxies, but how they came to be is unclear. Meanwhile, a correlation between the rate at which stars form in the central regions of galaxies and the amount of gas that falls into supermassive black holes (mass accretion rate) was known to exist, leading some scientists to suggest that the activity involved in star formation fuels the growth of black holes.

    The joint research team led by graduate student and JSPS fellow Takuma Izumi at the Graduate School of Science at the University of Tokyo revealed for the first time—with observational data collected by ALMA in Chile, and other telescopes—that dense molecular gas disks occupying regions as large as a few light-years at the centers of galaxies are supplying gas directly to the supermassive black holes.

    The team also succeeded in explaining, with a theoretical model, that the actual changes (balance of inflow and outflow) in gas levels they observed were the result of the increasing amount of gas falling into the supermassive black holes within the gas disks enhanced by strong turbulence generated by supernova explosions (an activity associated with star formation) when a star inside the dense gas disks dies.

    “The central regions of faraway galaxies, comprising a few light-years in scale, are hard to observe in detail because of their compactness, and there haven’t been many studies showing how black holes grow due to the lack of extensive research. So, this outcome is a big step forward as we successfully revealed one aspect of that process,” says Izumi. He continues, “We hope to expand our research to farther expanses of the universe by utilizing the superb capability of ALMA to help us understand comprehensively the growth of supermassive black holes over cosmic time.”

    These observation results were published as Izumi et al. “Do Circumnuclear Dense Gas Disks Drive Mass Accretion onto Supermassive Black Holes?” in the Astrophysical Journal Letters, issued in August 2016: http://iopscience.iop.org/article/10.3847/0004-637X/827/1/81/meta

    The research team members are: Takuma Izumi (The University of Tokyo), Nozomu Kawakatu (National Institute of Technology, Kure College), and Kotaro Kohno (The University of Tokyo)

    See the full article here .

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

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

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  • richardmitnick 2:30 pm on September 29, 2016 Permalink | Reply
    Tags: ALMA, ALMA Discovers Hidden Spiral Arms Embracing a Young Star, , , ,   

    From ALMA: “ALMA Discovers Hidden Spiral Arms Embracing a Young Star” 

    ALMA Array

    ALMA

    29 September 2016
    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

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

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    1
    ALMA peered into the Ophiuchus star-forming region to study the protoplanetary disk around the young star Elias 2-27. Astronomers discovered a striking spiral pattern in the disk. This feature is the product of density waves – gravitational perturbations in the disk. Credit: L. Pérez (MPIfR), B. Saxton (NRAO/AUI/NSF), ALMA (ESO/NAOJ/NRAO), NASA/JPL Caltech/WISE Team.

    Swirling around the young star Elias 2-27, astronomers discovered a stunning spiral-shape pinwheel of dust. This striking feature, seen with the Atacama Large Millimeter/submillimeter Array (ALMA), is the product of density waves – gravitational perturbations in the disk that produce sweeping arms reminiscent of a spiral galaxy, but on a much smaller scale.

    “These observations are the first direct evidence for density waves in a protoplanetary disk,” said Laura Perez, an astronomer with the Max Planck Institute for Radio Astronomy in Bonn, Germany, and lead author on a paper published in the journal Science.

    Previously, astronomers noted compelling spiral features on the surfaces of protoplanetary disks, but it was unknown if these same spiral patterns also emerged deep within the disk where planet formation takes place. ALMA, for the first time, was able to peer deep into the mid-plane of a disk and discovered the clear signature of spiral density waves.

    Nearest to the star, ALMA found a familiar flattened disk of dust, which extends past the orbit of Neptune in our own solar system. Beyond that point, ALMA detected a narrow band with significantly less dust, which may be indicative of a planet in formation. Springing from the outer edge of this gap are two sweeping spiral arms that extend more than 10 billion kilometers away from their host star.

    2
    ALMA discovered sweeping spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. This spiral feature was produced by density waves – gravitational perturbations in the disk. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

    Finding density waves at these extreme distances may have implications for planet-formation theory, Perez notes. The standard picture of planet formation begins with small planetesimals coming together under gravity. In the outer reaches of a disk, where there is a dearth of planetesimals, gravitational instabilities may also lead directly to the formation of a planet. ALMA’s detection of spiral density waves may be evidence that such a process is taking place.

    Elias 2-27 is located approximately 450 light-years from Earth in the Ophiuchus star-forming complex. Even though it contains only about half the mass of our Sun, this star has an unusually massive protoplanetary disk. The star is estimated to be at least one million years old and still encased in its parent molecular cloud, obscuring it from optical telescopes.

    “There are still questions of how these features form. Perhaps they are the result of a newly forged planet interacting with the protoplanetary disk or simply gravitational instabilities driven by the shear mass of the disk,” said Perez. “ALMA will further dissect this and other similar disks in an upcoming large program, helping astronomers understand the seemingly chaotic forces that eventually give rise to stable planetary systems like our own.”

    The team is composed of L. Perez (Max Planck Institute for Radio Astronomy, Bonn, Germany), J. Carpenter (Joint ALMA Observatory, Santiago, Chile), S. Andrews (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), L. Ricci (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), A. Isella (Rice University, Houston, Texas), H. Linz (Max Planck Institute for Astronomy, Heidelberg, Germany), A. Sargent (Caltech, Pasadena, Calif.), D. Wilner (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), T. Henning (Max Planck Institute for Astronomy, Heidelberg, Germany), A. Deller (The Netherlands Institute for Radio Astronomy, Dwingeloo), C. Chandler (National Radio Astronomy Observatory, Socorro, N.M.), C. Dullemond (Heidelberg University, Germany), J. Lazio (Caltech, Pasadena, Calif.), K. Menten (Max Planck Institute for Radio Astronomy, Bonn, Germany), S. Corder (Joint ALMA Observatory, Santiago, Chile), S. Storm (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.), L. Testi (European Southern Observatory, Garching, Germany), M. Tazzari (European Southern Observatory, Garching, Germany), W. Kwon (Korean Astronomy and Space Science Institute, Daejeon), N. Calvert (University of Michigan, Ann Arbor), J. Greaves (Cardiff University, U.K.), R. Harris (University of Illinois, Urbana), L. Mundy (University of Maryland, College Park).

    See the full article here .

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

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

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  • richardmitnick 7:31 am on September 29, 2016 Permalink | Reply
    Tags: ALMA, ALMA Catches Stellar Cocoon with Curious Chemistry, , , ,   

    From ALMA: “ALMA Catches Stellar Cocoon with Curious Chemistry” 

    ALMA Array

    ALMA

    29 September 2016
    Contacts

    Takashi Shimonishi
    Frontier Research Institute for Interdisciplinary Sciences
    Tohoku University, Sendai, Miyagi, Japan
    Email: shimonishi@astr.tohoku.ac.jp

    Masaaki Hiramatsu
    NAOJ Chile Observatory EPO officer
    Tel: +81 422 34 3630
    Email: hiramatsu.masaaki@nao.ac.jp

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

    1

    A hot and dense mass of complex molecules, cocooning a newborn star, has been discovered by a Japanese team of astronomers using ALMA. This unique hot molecular core is the first of its kind to have been detected outside the Milky Way galaxy. It has a very different molecular composition from similar objects in our own galaxy — a tantalising hint that the chemistry taking place across the Universe could be much more diverse than expected.

    A team of Japanese researchers have used the power of the Atacama Large Millimeter/submillimeter Array (ALMA) to observe a massive star known as ST11 [1] in our neighbouring dwarf galaxy, the Large Magellanic Cloud (LMC). Emission from a number of molecular gases was detected. These indicated that the team had discovered a concentrated region of comparatively hot and dense molecular gas around the newly ignited star ST11. This was evidence that they had found something never before seen outside of the Milky Way — a hot molecular core [2].

    Takashi Shimonishi, an astronomer at Tohoku University, Japan, and the paper’s lead author enthused: “This is the first detection of an extragalactic hot molecular core, and it demonstrates the great capability of new generation telescopes to study astrochemical phenomena beyond the Milky Way.”

    The ALMA observations revealed that this newly discovered core in the LMC has a very different composition to similar objects found in the Milky Way. The most prominent chemical signatures in the LMC core include familiar molecules such as sulfur dioxide, nitric oxide, and formaldehyde — alongside the ubiquitous dust. But several organic compounds, including methanol (the simplest alcohol molecule), had remarkably low abundance in the newly detected hot molecular core. In contrast, cores in the Milky Way have been observed to contain a wide assortment of complex organic molecules, including methanol and ethanol.

    Takashi Shimonishi explains: “The observations suggest that the molecular compositions of materials that form stars and planets are much more diverse than we expected.”

    4
    Fig.2 Left: Distributions of molecular line emission from a hot molecular core in the Large Magellanic Cloud observed with ALMA. Emissions from dust, sulfur dioxide (SO2), nitric oxide (NO), and formaldehyde (H2CO) are shown as examples. Right: An infrared image of the surrounding star-forming region (based on the 8 micron data provided by the NASA/Spitzer Space Telescope). Credit: T. Shimonishi/Tohoku University, ALMA (ESO/NAOJ/NRAO)

    The LMC has a low abundance of elements other than hydrogen or helium [3]. The research team suggests that this very different galactic environment has affected the molecule-forming processes taking place surrounding the newborn star ST11. This could account for the observed differences in chemical compositions.

    It is not yet clear if the large, complex molecules detected in the Milky Way exist in hot molecular cores in other galaxies. Complex organic molecules are of very special interest because some are connected to prebiotic molecules formed in space. This newly discovered object in one of our nearest galactic neighbours is an excellent target to help astronomers address this issue. It also raises another question: how could the chemical diversity of galaxies affect the development of extragalactic life?

    Notes

    [1] ST11’s full name is 2MASS J05264658-6848469. This catchily-named young massive star is defined as a Young Stellar Object. Although it currently appears to be a single star, it is possible that it will prove to be a tight cluster of stars, or possibly a multiple star system. It was the target of the science team’s observations and their results led them to realise that ST11 is enveloped by a hot molecular core.

    [2] Hot molecular cores must be: (relatively) small, with a diameter of less than 0.3 light-years; have a density over a thousand billion (1012) molecules per cubic metre (far lower than the Earth’s atmosphere, but high for an interstellar environment); warm in temperature, at over –173 degrees Celsius. This makes them at least 80 degrees Celsius warmer than a standard molecular cloud, despite being of similar density. These hot cores form early on in the evolution of massive stars and they play a key role in the formation of complex chemicals in space.

    [3] The nuclear fusion reactions that take place when a star has stopped fusing hydrogen to helium generate heavier elements. These heavier elements get blasted into space when massive dying stars explode as supernovae. Therefore, as our Universe has aged, the abundance of heavier elements has increased. Thanks to its low abundance of heavier elements, the LMC provides insight into the chemical processes that were taking place in the earlier Universe.

    More information

    This research was presented in a paper published in the Astrophysical Journal on August 9, 2016, entitled The Detection of a Hot Molecular Core in the Large Magellanic Cloud with ALMA.

    The team is composed of Takashi Shimonishi (Frontier Research Institute for Interdisciplinary Sciences & Astronomical Institute, Tohoku University, Japan), Takashi Onaka (Department of Astronomy, The University of Tokyo, Japan), Akiko Kawamura (National Astronomical Observatory of Japan, Japan) and Yuri Aikawa (Center for Computational Sciences, The University of Tsukuba, Japan).

    See the full article here .

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

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

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

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  • richardmitnick 2:39 pm on September 22, 2016 Permalink | Reply
    Tags: ALMA, ALMA Explores the Hubble Ultra Deep Field, , ,   

    From ALMA: “ALMA Explores the Hubble Ultra Deep Field” 

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

    22 September 2016

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

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    James Dunlop
    University of Edinburgh
    Edinburgh, United Kingdom
    Email: jsd@roe.ac.uk

    Fabian Walter
    Max-Planck Institut für Astronomie
    Heidelberg, Germany
    Email: walter@mpia.de

    Manuel Aravena
    Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales
    Santiago, Chile
    Email: manuel.aravenaa@mail.udp.cl

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

    1
    This image combines a background picture taken by the NASA/ESA Hubble Space Telescope (blue/green) with a new very deep ALMA view of this field (orange, marked with circles). All the objects that ALMA sees appear to be massive star-forming galaxies. This image is based on the ALMA survey by J. Dunlop and colleagues, covering the full HUDF area. Credit: ALMA (ESO/NAOJ/NRAO)/NASA/ESA/J. Dunlop et al. and S. Beckwith (STScI) and the HUDF Team.

    2
    These cutout images are from a combination of a background picture taken by the NASA/ESA Hubble Space Telescope (blue/green) with a new very deep ALMA view of the field (orange, marked with circles). All the objects that ALMA sees appear to be massive star-forming galaxies.
    This image is based on the ALMA survey by J. Dunlop and colleagues, covering the full HUDF area. Credit:ALMA (ESO/NAOJ/NRAO)/NASA/ESA/J. Dunlop et al. and S. Beckwith (STScI) and the HUDF Team.

    5
    Animated GIF showing a trove of galaxies, rich in dust and cold gas (indicating star-forming potential) that was imaged by ALMA (orange) in the Hubble Ultra Deep Field. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble

    International teams of astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to explore the distant corner of the Universe first revealed in the iconic images of the Hubble Ultra Deep Field (HUDF). These new ALMA observations are significantly deeper and sharper than previous surveys at millimetre wavelengths. They clearly show how the rate of star formation in young galaxies is closely related to their total mass in stars. They also trace the previously unknown abundance of star-forming gas at different points in time, providing new insights into the “Golden Age” of galaxy formation approximately 10 billion years ago.

    The new ALMA results will be published in a series of papers appearing in the Astrophysical Journal and Monthly Notices of the Royal Astronomical Society. These results are also among those being presented this week at the Half a Decade of ALMA conference in Palm Springs, California, USA.

    In 2004 the Hubble Ultra Deep Field images — pioneering deep-field observations with the NASA/ESA Hubble Space Telescope — were published. These spectacular pictures probed more deeply than ever before and revealed a menagerie of galaxies stretching back to less than a billion years after the Big Bang. The area was observed several times by Hubble and many other telescopes, resulting in the deepest view of the Universe to date.

    Astronomers using ALMA have now surveyed this seemingly unremarkable, but heavily studied, window into the distant Universe for the first time both deeply and sharply in the millimetre range of wavelengths [1]. This allows them to see the faint glow from gas clouds and also the emission from warm dust in galaxies in the early Universe.

    ALMA has observed the HUDF for a total of around 50 hours up to now. This is the largest amount of ALMA observing time spent on one area of the sky so far.

    One team led by Jim Dunlop (University of Edinburgh, United Kingdom) used ALMA to obtain the first deep, homogeneous ALMA image of a region as large as the HUDF. This data allowed them to clearly match up the galaxies that they detected with objects already seen with Hubble and other facilities.

    This study showed clearly for the first time that the stellar mass of a galaxy is the best predictor of star formation rate in the high redshift Universe. They detected essentially all of the high-mass galaxies [2] and virtually nothing else.

    Jim Dunlop, lead author on the deep imaging paper sums up its importance: “This is a breakthrough result. For the first time we are properly connecting the visible and ultraviolet light view of the distant Universe from Hubble and far-infrared/millimetre views of the Universe from ALMA.”

    The second team, led by Manuel Aravena of the Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile, and Fabian Walter of the Max Planck Institute for Astronomy in Heidelberg, Germany, conducted a deeper search across about one sixth of the total HUDF [3].

    “We conducted the first fully blind, three-dimensional search for cool gas in the early Universe,” said Chris Carilli, an astronomer with the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, USA and member of the research team. “Through this, we discovered a population of galaxies that is not clearly evident in any other deep surveys of the sky.” [4]

    Some of the new ALMA observations were specifically tailored to detect galaxies that are rich in carbon monoxide, indicating regions primed for star formation. Even though these molecular gas reservoirs give rise to the star formation activity in galaxies, they are often very hard to see with Hubble. ALMA can therefore reveal the “missing half” of the galaxy formation and evolution process.

    “The new ALMA results imply a rapidly rising gas content in galaxies as we look back further in time,” adds lead author of two of the papers, Manuel Aravena (Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile). “This increasing gas content is likely the root cause for the remarkable increase in star formation rates during the peak epoch of galaxy formation, some 10 billion years ago.”

    The results presented today are just the start of a series of future observations to probe the distant Universe with ALMA. For example, a planned 150-hour observing campaign of the HUDF will further illuminate the star-forming potential history of the Universe.

    “By supplementing our understanding of this missing star-forming material, the forthcoming ALMA Large Program will complete our view of the galaxies in the iconic Hubble Ultra Deep Field,” concludes Fabian Walter.
    Notes

    [1] Astronomers specifically selected the area of study in the HUDF, a region of space in the faint southern constellation of Fornax (The Furnace), so ground-based telescopes in the southern hemisphere, like ALMA, could probe the region, expanding our knowledge about the very distant Universe.

    Probing the deep, but optically invisible, Universe was one of the primary science goals for ALMA.

    [2] In this context “high mass” means galaxies with stellar masses greater than 20 billion times that of the Sun ( 2 × 1010 solar masses). For comparison, the Milky Way is a large galaxy and has a mass of around 100 billion solar masses.

    [3] This region of sky is about seven hundred times smaller than the area of the disc of the full Moon as seen from Earth. One of the most startling aspects of the HUDF was the vast number of galaxies found in such a tiny fraction of the sky.

    [4] ALMA’s ability to see a completely different portion of the electromagnetic spectrum from Hubble allows astronomers to study a different class of astronomical objects, such as massive star-forming clouds, as well as objects that are otherwise too faint to observe in visible light, but visible at millimetre wavelengths.

    The search is referred to as “blind” as it was not focussed on any particular object.

    The new ALMA observations of the HUDF include two distinct, yet complementary types of data: continuum observations, which reveal dust emission and star formation, and a spectral emission line survey, which looks at the cold molecular gas fueling star formation. The second survey is particularly valuable because it includes information about the degree to which light from distant objects has been redshifted by the expansion of the Universe. Greater redshift means that an object is further away and seen farther back in time. This allows astronomers to create a three-dimensional map of star-forming gas as it evolves over cosmic time.
    More information

    This research was presented in papers titled:

    “A deep ALMA image of the Hubble Ultra Deep Field”, by J. Dunlop et al., to appear in the Monthly Notices of the Royal Astronomical Society.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Search for the [CII] Line and Dust Emission in 6 < z < 8 Galaxies”, by M. Aravena et al., to appear in the Astrophysical Journal.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Molecular Gas Reservoirs in High-Redshift Galaxies”, by R. Decarli et al., to appear in the Astrophysical Journal.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: CO Luminosity Functions and the Evolution of the Cosmic Density of Molecular Gas”, by R. Decarli et al., to appear in the Astrophysical Journal.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Continuum Number Counts, Resolved 1.2-mm Extragalactic Background, and Properties of the Faintest Dusty Star Forming Galaxies”, by M. Aravena et al., to appear in the Astrophysical Journal.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Survey Description”, by F. Walter et al., to appear in the Astrophysical Journal.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: the Infrared excess of UV-selected z= 2-10 Galaxies as a Function of UV-continuum Slope and Stellar Mass”, by R. Bouwens et al., to appear in the Astrophysical Journal.

    “The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Implication for spectral line intensity mapping at millimeter wavelengths and CMB spectral distortions”, by C. L. Carilli et al. to appear in the Astrophysical Journal.

    The teams are composed of:

    M. Aravena (Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile), R. Decarli (Max-Planck Institut für Astronomie, Heidelberg, Germany), F. Walter (Max-Planck Institut für Astronomie, Heidelberg, Germany; Astronomy Department, California Institute of Technology, USA; NRAO, Pete V. Domenici Array Science Center, USA), R. Bouwens (Leiden Observatory, Leiden, The Netherlands; UCO/Lick Observatory, Santa Cruz, USA), P.A. Oesch (Astronomy Department, Yale University, New Haven, USA), C.L. Carilli (Leiden Observatory, Leiden, The Netherlands; Astrophysics Group, Cavendish Laboratory, Cambridge, UK), F.E. Bauer (Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Institute of Astrophysics, Chile; Space Science Institute, Boulder, USA), E. Da Cunha (Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia; Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Australia), E. Daddi (Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, Orme des Merisiers, France), J. Gónzalez-López (Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Santiago, Chile), R.J. Ivison (European Southern Observatory, Garching bei München, Germany; Institute for Astronomy, University of Edinburgh, Edinburgh, UK), D.A. Riechers (Cornell University, 220 Space Sciences Building, Ithaca, USA), I. Smail (Institute for Computational Cosmology, Durham University, Durham, UK), A.M. Swinbank (Institute for Computational Cosmology, Durham University, Durham, UK), A. Weiss (Max-Planck-Institut für Radioastronomie, Bonn, Germany), T. Anguita (Departamento de Ciencias Físicas, Universidad Andrés Bello, Santiago, Chile; Millennium Institute of Astrophysics, Chile), R. Bacon (Université Lyon 1, Saint Genis Laval, France), E. Bell (Department of Astronomy, University of Michigan, USA), F. Bertoldi (Argelander Institute for Astronomy, University of Bonn, Bonn, Germany), P. Cortes (Joint ALMA Observatory – ESO, Santiago, Chile; NRAO, Pete V. Domenici Array Science Center, USA), P. Cox (Joint ALMA Observatory – ESO, Santiago, Chile), J. Hodge (Leiden Observatory, Leiden, The Netherlands), E. Ibar (Instituto de Física y Astronomía, Universidad de Valparaíso, Valparaiso, Chile), H. Inami (Université Lyon 1, Saint Genis Laval, France), L. Infante (Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Santiago, Chile), A. Karim (Argelander Institute for Astronomy, University of Bonn, Bonn, Germany), B. Magnelli (Argelander Institute for Astronomy, University of Bonn, Bonn, Germany), K. Ota (Kavli Institute for Cosmology, University of Cambridge, Cambridge, UK; Cavendish Laboratory, University of Cambridge, UK), G. Popping (European Southern Observatory, Garching bei München, Germany), P. van der Werf (Leiden Observatory, Leiden, The Netherlands), J. Wagg (SKA Organization, Cheshire, UK), Y. Fudamoto (European Southern Observatory, Garching bei München, Germany; Universität-Sternwarte München, München, Germany), D. Elbaz (Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, France), S. Chapman (Dalhousie University, Halifax, Nova Scotia, Canada), L.Colina (ASTRO-UAM, UAM, Unidad Asociada CSIC, Spain), H.W. Rix (Max-Planck Institut für Astronomie, Heidelberg, Germany), Mark Sargent (Astronomy Centre, University of Sussex, Brighton, UK), Arjen van der Wel (Max-Planck Institut für Astronomie, Heidelberg, Germany)

    K. Sheth (NASA Headquarters, Washington DC, USA), Roberto Neri (IRAM, Saint-Martin d’Hères, France), O. Le Fèvre (Aix Marseille Université, Laboratoire d’Astrophysique de Marseille, Marseille, France), M. Dickinson (Steward Observatory, University of Arizona, USA), R. Assef (Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile), I. Labbé (Leiden Observatory, Leiden University, Netherlands), S. Wilkins (Astronomy Centre, University of Sussex, Brighton, UK), J.S. Dunlop (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), R.J. McLure (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), A.D. Biggs (ESO, Garching, Germany), J.E. Geach (University of Hertfordshire, Hatfield, United Kingdom), M.J. Michałowski (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), W. Rujopakarn (Chulalongkorn University, Bangkok, Thailand), E. van Kampen (ESO, Garching, Germany), A. Kirkpatrick (University of Massachusetts, Amherst, Massachusetts, USA), A. Pope (University of Massachusetts, Amherst, Massachusetts, USA), D. Scott (University of British Columbia, Vancouver, British Columbia, Canada), T.A. Targett (Sonoma State University, Rohnert Park, California, USA), I. Aretxaga (Instituto Nacional de Astrofísica, Optica y Electronica, Mexico), J.E. Austermann (NIST Quantum Devices Group, Boulder, Colorado, USA), P.N. Best (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), V.A. Bruce (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), E.L. Chapin (Herzberg Astronomy and Astrophysics, National Research Council Canada, Victoria, Canada), S. Charlot (Sorbonne Universités, UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, Paris, France), M. Cirasuolo (ESO, Garching, Germany), K.E.K. Coppin (University of Hertfordshire, College Lane, Hatfield, United Kingdom), R.S. Ellis (ESO, Garching, Germany), S.L. Finkelstein (The University of Texas at Austin, Austin, Texas, USA), C.C. Hayward (California Institute of Technology, Pasadena, California, USA), D.H. Hughes (Instituto Nacional de Astrofísica, Optica y Electronica, Mexico), S. Khochfar (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), M.P. Koprowski (University of Hertfordshire, College Lane, Hatfield, United Kingdom), D. Narayanan (Haverford College, Haverford, Pennsylvania, USA), C. Papovich (Texas A & M University, College Station, Texas, USA), J.A. Peacock (University of Edinburgh, Royal Observatory, Edinburgh, United Kingdom), B. Robertson (University of California, Santa Cruz, Santa Cruz, California, USA), T. Vernstrom (Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, Ontario, Canada), G.W. Wilson (University of Massachusetts, Amherst, Massachusetts, USA) and M. Yun (University of Massachusetts, Amherst, Massachusetts, USA).

    Links

    Research paper 1 (Dunlop, J. S. et al.)
    Research paper 2 (Aravena, M. et al.)
    Research paper 3 (Decarli, R. et al.)
    Research paper 4 (Decarli, R. et al.)
    Research paper 5 (Aravena, M. et al.)
    Research paper 6 (Walter, F. et al.)
    Research paper 7 (Bouwens, R. et al.)
    Research paper 8 (Carilli, C. L. et al.)
    NRAO press release
    Max Planck Institute for Astronomy press release (English | German)
    Photos of ALMA

    See the full article here .

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

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

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    ESO 50

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