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  • richardmitnick 11:53 am on April 21, 2017 Permalink | Reply
    Tags: ALMA, An Exploration of Dusty Galaxies, , , , , , Submillimeter Common-User Bolometer Array (SCUBA-2), UKIDSS Ultra Deep Survey field   

    From AAS NOVA: ” An Exploration of Dusty Galaxies” 

    AASNOVA

    American Astronomical Society

    21 April 2017
    Susanna Kohler

    1
    A small section of the UKIDSS Ultra Deep Survey field. A new study of 53 submillimeter galaxies in this field reveals more about galaxies in our early universe. [University of Nottingham/Omar Almaini]

    Submillimeter galaxies — i.e., galaxies that we detect in the submillimeter wavelength range — are mysterious creatures. It’s only within the last couple decades that we’ve had telescope technology capable of observing them, and we’re only now getting to the point where angular resolution limits allow us to examine them closely. A new study has taken advantage of new capabilities to explore the properties of a sample of 52 of these galaxies.

    Dusty Star Formation

    Submillimeter galaxies are generally observed in the early universe. Though they’re faint in other wavebands, they’re extremely luminous in infrared and submillimeter — their infrared luminosities are typically trillions of times the Sun’s luminosity. This is thought to be because these galaxies are very actively forming stars at rates of hundreds of times that of the Milky Way!

    2
    Example 10” × 10” true-color images of ten submillimeter galaxies in the authors’ ALMA-identified sample. [Simpson et al. 2017]

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

    Submillimeter galaxies are also extremely dusty, so we don’t see their star formation directly in optical wavelengths. Instead, we see the stellar light after it’s been absorbed and reemitted by interstellar dust lanes — we’re indirectly observing heavily obscured star formation.

    Why look for submillimeter galaxies? Studying them can help us to learn about galaxy and star formation early in our universe’s history, and help us to understand how the universe has evolved into what we see locally today.

    Submillimeter Struggles

    Due to angular resolution limitations in the past, we often couldn’t pin down the exact locations of submillimeter galaxies, preventing us from examining them properly. But now a team of scientists has used the Atacama Large Millimeter/submillimeter array (ALMA) to precisely locate 52 submillimeter galaxies identified by the Submillimeter Common-User Bolometer Array (SCUBA-2) in the UKIDSS Ultra Deep Survey field.

    East Asia Observatory James Clerk Maxwell telescope, Mauna Kea, Hawaii, USA

    The precise locations made possible by ALMA allowed the team — led by James Simpson (University of Edinburgh and Durham University) — to identify the multi-wavelength properties of these galaxies in a pilot study that they hope to extend to many more similar galaxies in the future.

    3
    Photometric redshift distribution of the ALMA-identified submillimeter galaxies in the authors’ sample (grey). [Simpson et al. 2017]

    Lessons from Distant Galaxies

    What did Simpson and collaborators learn in this study?

    1. For the set of galaxies for which the team could measure photometric redshifts, the median redshift was z ~ 2.65 (though redshifts ranged up to z ~ 5).
    2. Submillimeter galaxies are cooler and larger than local far-infrared galaxies (known as ULIRGs). The authors therefore argue that it’s unlikely that ULIRGs are evolved versions of submillimeter galaxies.
    3. Estimates of dust mass in these galaxies suggest that effectively all of the optical-to-near-infrared light from colocated stars is obscured by dust.
    4. Estimates of the future stellar mass of these galaxies suggest that they cannot evolve into lenticular or spiral galaxies. Instead, the authors conclude, submillimeter galaxies must be the progenitors of local elliptical galaxies.

    Citation

    J. M. Simpson et al 2017 ApJ 839 58. doi:10.3847/1538-4357/aa65d0

    Related Journal Articles

    The scuba-2 cosmology legacy survey: alma resolves the rest-frame far-infrared emission of sub-millimeter galaxies doi: 10.1088/0004-637X/799/1/81
    The scuba-2 cosmology legacy survey: alma resolves the bright-end of the sub-millimeter number counts doi: 10.1088/0004-637X/807/2/128
    An alma survey of submillimeter galaxies in the extended chandra deep field south: the redshift distribution and evolution of submillimeter galaxies doi: 10.1088/0004-637X/788/2/125
    The scuba-2 cosmology legacy survey: multiwavelength counterparts to 103 submillimeter galaxies in the ukidss-uds field doi: 10.3847/0004-637X/820/2/82
    The scuba-2 cosmology legacy survey: ultraluminous star-forming galaxies in a z = 1.6 cluster doi: 10.1088/0004-637X/782/1/19
    Extremely red submillimeter galaxies: new z ≳ 4–6 candidates discovered using alma and jansky vla doi: 10.3847/1538-4357/835/2/286

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

    See the full article here .

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  • richardmitnick 10:23 am on April 20, 2017 Permalink | Reply
    Tags: ALMA, , , , , Feeding a Baby Star with a Dusty Hamburger, HH 212 protostellar system   

    From ALMA: “Feeding a Baby Star with a Dusty Hamburger” 

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

    20 April 2017
    Dr. Chin-Fei Lee
    Academia Sinica
    Institute of Astrophysics and Astronomy
    Tel: +886-2-2366-5445
    Email: cflee@asiaa.sinica.edu.tw

    Dr. Mei-Yin Chou
    Academia Sinica
    Institute of Astrophysics and Astronomy
    Tel: +886-2-2366-5415
    Email: cmy@asiaa.sinica.edu.tw

    Valeria Foncea

    Education and Public Outreach Officer

    Joint ALMA Observatory

    Santiago, Chile

    Tel: +56 2 467 6258

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

    1
    A cartoon showing an accretion disk feeding the central protostar and jets coming out from it. Credit: Yin-Chih Tsai/ASIAA

    An international research team, led by Chin-Fei Lee in Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan), has made a new high-fidelity image with the Atacama Large Millimeter/submillimeter Array (ALMA), catching a protostar (baby star) being fed with a dusty “hamburger”, which is a dusty accretion disk. This new image not only confirms the formation of an accretion disk around a very young protostar, but also reveals the vertical structure of the disk for the first time in the earliest phase of star formation. It not only poses a big challenge on some current theories of disk formation, but also potentially brings us key insights on the processes of grain growth and settling that are important to planet formation.

    “It is so amazing to see such a detailed structure of a very young accretion disk. For many years, astronomers have been searching for accretion disks in the earliest phase of star formation, to determine their structure, how they are formed, and how the accretion process takes place. Now using the ALMA with its full power of resolution, we not only detect an accretion disk but also resolve it, especially its vertical structure, in detail”, says Chin-Fei Lee at ASIAA.

    “In the earliest phase of star formation, there are theoretical difficulties in producing such a disk, because magnetic fields can slow down the rotation of collapsing material, preventing such a disk from forming around a very young protostar. This new finding implies that the retarding effect of magnetic fields in disk formation may not be as efficient as we thought before,” says Zhi-Yun Li at University of Virginia.

    2
    Figure 1. Jet and disk in the HH 212 protostellar system: (a) A composite image for the jet in different molecules, produced by combining the images from the Very Large Telescope (McCaughrean et al. 2002) and ALMA (Lee et al. 2015). Orange image around the center shows the dusty envelope+disk at submillimeter wavelength obtained with ALMA at 200 AU resolution. (b) A zoom-in to the very center for the dusty disk at 8 AU resolution. Asterisks mark the possible position of the central protostar. A dark lane is seen in the equator, causing the disk to appear as a “hamburger”. A size scale of our solar system is shown in the lower right corner for size comparison. (c) An accretion disk model that reproduces the observed dust emission in the disk. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al.

    HH 212 is a nearby protostellar system in Orion at a distance of about 1300 ly. The central protostar is very young with an age of only ~40,000 years (which is about 10 millionth of the age of our Sun) and a mass of around a fifth part the one of the Sun. It drives a powerful bipolar jet and thus must accrete material efficiently. Previous search at a resolution of 200 AU only found a flattened envelope spiraling toward the center and a hint of a small dusty disk near the protostar. Now with ALMA at a resolution of 8 AU, which is 25 times higher, we not only detect but also spatially resolve the dusty disk at submillimeter wavelength.

    3
    An accretion disk model that reproduces the observed disk emission. (a) The accretion disk model with the disk surface temperature. (b) The image created based on the model, is roughly the same as the observed image of the disk. Credit: Lee et al.

    The disk is nearly edge-on and has a radius of about 60 AU. Interestingly, it shows a prominent equatorial dark lane sandwiched between two brighter features, due to relatively low temperature and high optical depth near the disk midplane. For the first time, this dark lane is seen at submillimeter wavelength, producing a “hamburger”-shaped appearance that is reminiscent of the scattered-light image of an edge-on disk in optical and near infrared. The structure of the dark lane clearly implies that the disk is flared, as expected in an accretion disk model.

    Our observations open an exciting possibility of directly detecting and characterizing small disks around the youngest protostars through high-resolution imaging with ALMA, which provides strong constraints on theories of disk formation. Our observations of the vertical structure can also yield key insights on the processes of grain growth and settling that are important to planet formation in the earliest phase.

    This research was presented in a paper First detection of equatorial dark dust lane in a protostellar disk at submillimeter wavelength, by Lee et al. to appear in the journal Science Advances.

    The team is composed of Chin-Fei Lee (ASIAA, Taiwan; National Taiwan University, Taiwan), Zhi-Yun Li (University of Virginia, USA), Paul T.P. Ho (ASIAA, Taiwan; East Asia Observatory), Naomi Hirano (ASIAA, Taiwan), Qizhou Zhang (Harvard-Smithsonian Center for Astrophysics, USA), and Hsien Shang (ASIAA, Taiwan).

    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 2:41 pm on April 12, 2017 Permalink | Reply
    Tags: ALMA, , , , , , Planetary body 2014 UZ224 more informally known as DeeDee,   

    From ALMA: “ALMA Investigates ‘DeeDee,’ a Distant, Dim Member of Our Solar System” 

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

    April 12, 2017
    Nicolás Lira T.
    Press Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nicolas.lira@alma.cl

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

    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
    Artist concept of the planetary body 2014 UZ224, more informally known as DeeDee. ALMA was able to observe the faint millimeter-wavelength “glow” emitted by the object, confirming it is roughly 635 kilometers across. At this size, DeeDee should have enough mass to be spherical, the criterion necessary for astronomers to consider it a dwarf planet, though it has yet to receive that official designation. Credit: Alexandra Angelich (NRAO/AUI/NSF)

    Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have revealed extraordinary details about a recently discovered far-flung member of our solar system, the planetary body 2014 UZ224, more informally known as DeeDee.

    2
    ALMA image of the faint millimeter-wavelength “glow” from the planetary body 2014 UZ224, more informally known as DeeDee. At three times the distance of Pluto from the Sun, DeeDee is the second most distant known TNO with a confirmed orbit in our solar system. Credit: ALMA (ESO/NAOJ/NRAO)

    At about three times the current distance of Pluto from the Sun, DeeDee is the second most distant known trans-Neptunian object (TNO) with a confirmed orbit, surpassed only by the dwarf planet Eris. Astronomers estimate that there are tens-of-thousands of these icy bodies in the outer solar system beyond the orbit of Neptune.

    The new ALMA data reveal, for the first time, that DeeDee is roughly 635 kilometers across, or about two-thirds the diameter of the dwarf planet Ceres, the largest member of our asteroid belt. At this size, DeeDee should have enough mass to be spherical, the criterion necessary for astronomers to consider it a dwarf planet, though it has yet to receive that official designation.

    “Far beyond Pluto is a region surprisingly rich with planetary bodies. Some are quite small but others have sizes to rival Pluto, and could possibly be much larger,” said David Gerdes, a scientist with the University of Michigan and lead author on a paper appearing in the Astrophysical Journal Letters. “Because these objects are so distant and dim, it’s incredibly difficult to even detect them, let alone study them in any detail. ALMA, however, has unique capabilities that enabled us to learn exciting details about these distant worlds.”

    Currently, DeeDee is about 92 astronomical units (AU) from the Sun. An astronomical unit is the average distance from the Earth to the Sun, or about 150 million kilometers. At this tremendous distance, it takes DeeDee more than 1,100 years to complete one orbit. Light from DeeDee takes nearly 13 hours to reach Earth.

    Gerdes and his team announced the discovery of DeeDee in the fall of 2016. They found it using the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile as part of ongoing observations for the Dark Energy Survey, an optical survey of about 12 percent of the sky that seeks to understand the as-yet mysterious force that is accelerating the expansion of the universe.

    The Dark Energy Survey produces vast troves of astronomical images, which give astronomers the opportunity to also search for distant solar system objects.

    The initial search, which includes nearly 15,000 images, identified more than 1.1 billion candidate objects. The vast majority of these turned out to be background stars and even more distant galaxies. A small fraction, however, were observed to move slowly across the sky over successive observations, the telltale sign of a TNO.

    One such object was identified on 12 separate images. The astronomers informally dubbed it DeeDee, which is short for Distant Dwarf.

    The optical data from the Blanco telescope enabled the astronomers to measure DeeDee’s distance and orbital properties, but they were unable to determine its size or other physical characteristics. It was possible that DeeDee was a relatively small member of our solar system, yet reflective enough to be detected from Earth. Or, it could be uncommonly large and dark, reflecting only a tiny portion of the feeble sunlight that reaches it; both scenarios would produce identical optical data.

    Since ALMA observes the cold, dark universe, it is able to detect the heat – in the form of millimeter-wavelength light – emitted naturally by cold objects in space. The heat signature from a distant solar system object would be directly proportional to its size.

    “We calculated that this object would be incredibly cold, only about 30 degrees Kelvin, just a little above absolute zero,” said Gerdes.

    While the reflected visible light from DeeDee is only about as bright as a candle seen halfway the distance to the moon, ALMA was able to quickly home in on the planetary body’s heat signature and measure its brightness in millimeter-wavelength light.

    This allowed astronomers to determine that it reflects only about 13 percent of the sunlight that hits it. That is about the same reflectivity of the dry dirt found on a baseball infield.

    By comparing these ALMA observations to the earlier optical data, the astronomers had the information necessary to calculate the object’s size. “ALMA picked it up fairly easily,” said Gerdes. “We were then able to resolve the ambiguity we had with the optical data alone.”

    Objects like DeeDee are cosmic leftovers from the formation of the solar system. Their orbits and physical properties reveal important details about the formation of planets, including Earth.

    This discovery is also exciting because it shows that it is possible to detect very distant, slowly moving objects in our own solar system. The researchers note that these same techniques could be used to detect the hypothesized “Planet Nine” that may reside far beyond DeeDee and Eris.

    “There are still new worlds to discover in our own cosmic backyard,” concludes Gerdes. “The solar system is a rich and complicated place.”

    3

    Orbits of objects in our solar system, showing the current location of the planetary body ‘DeeDee’.
    Credit: Alexandra Angelich (NRAO/AUI/NSF)

    Additional information

    This research is presented in a paper titled “Discovery and physical characterization of a large scattered disk object at 92 AU,” appearing in the Astrophysical Journal Letters.

    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

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

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

    ALMA Array

    NRAO ALMA

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

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

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

     
  • richardmitnick 2:25 pm on April 7, 2017 Permalink | Reply
    Tags: ALMA, ALMA Captures Explosive Star Birth, , , , , Orion Molecular Cloud   

    From ALMA: “ALMA Captures Explosive Star Birth” 

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

    07 April 2017
    Contacts

    John Bally
    University of Colorado, USA
    Email: john.bally@Colorado.EDU

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

    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

    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
    Stellar explosions are most often associated with supernovae, the spectacular deaths of stars. But new ALMA observations of the Orion Nebula complex provide insights into explosions at the other end of the stellar life cycle, star birth. Astronomers captured these dramatic images of the remains of a 500-year-old explosion as they explored the firework-like debris from the birth of a group of massive stars, demonstrating that star formation can be a violent and explosive process too. The colours in the ALMA data represent the relative Doppler shifting of the millimetre-wavelength light emitted by carbon monoxide gas. The blue colour in the ALMA data represents gas approaching at the highest speeds; the red colour is from gas moving toward us more slowly. The background image includes optical and near-infrared imaging from both the Gemini South and ESO Very Large Telescope. The famous Trapezium Cluster of hot young stars appears towards the bottom of this image. The ALMA data do not cover the full image shown here. Credit: ALMA (ESO/NAOJ/NRAO), J. Bally/H. Drass et al.

    3
    In one of the most detailed astronomical images ever produced, NASA/ESA’s Hubble Space Telescope captured an unprecedented look at the Orion Nebula. … This extensive study took 105 Hubble orbits to complete. All imaging instruments aboard the telescope were used simultaneously to study Orion. The Advanced Camera mosaic covers approximately the apparent angular size of the full moon.

    5
    Photo taken by Rogelio Bernal Andreo in October 2010 of the Orion constellation showing the surrounding nebulas of the Orion Molecular Cloud complex. Also captured is the red supergiant Betelgeuse (top left) and the famous belt of Orion composed of the OB stars Altitak, Alnilam and Mintaka. To the bottom right can be found the star Rigel. The red crescent shape is Barnard’s Loop. The photograph appeared as the Astronomy Picture of the Day on October 23, 2010.
    Date 23 August 2012
    Source http://deepskycolors.com/astro/JPEG/RBA_Orion_HeadToToes.jpg

    Star birth can be a violent and explosive event, as dramatically illustrated in new ALMA images.

    Around 500 years ago, a pair of adolescent protostars had a perilously close encounter that blasted their stellar nursery apart.

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have examined the widely scattered debris from this explosive event, gaining new insights into the sometimes-fierce relationship among sibling stars.

    Shortly after starting to form some 100,000 years ago, several protostars in the Orion Molecular Cloud 1 (OMC-1), a dense and active star factory about 1,500 light-years from Earth just behind the Orion Nebula, latched onto each other gravitationally and gradually drew closer.

    Eventually, two of these stars either grazed each other or collided, triggering a powerful eruption that launched other nearby protostars and hundreds of giant streamers of dust and gas into interstellar space at speeds greater than 150 kilometers per second. This cataclysmic interaction released as much energy as our Sun emits over the course of 10 million years.

    Today, the remains of this spectacular explosion are visible from Earth.

    2
    Credit: ALMA (ESO/NAOJ/NRAO), J. Bally

    “What we see in this once calm stellar nursery is a cosmic version of a fireworks display, with giant streamers rocketing off in all directions,” said John Bally with the University of Colorado and lead author on a paper published in the Astrophysical Journal.

    3
    Stellar explosions are most often associated with supernovae, the spectacular deaths of stars. But new ALMA observations of the Orion Nebula complex provide insights into explosions at the other end of the stellar life cycle, star birth. Astronomers captured these dramatic images of the remains of a 500-year-old explosion as they explored the firework-like debris from the birth of a group of massive stars, demonstrating that star formation can be a violent and explosive process too. The colours in the ALMA data represent the relative Doppler shifting of the millimetre-wavelength light emitted by carbon monoxide gas. The blue colour in the ALMA data represents gas approaching at the highest speeds; the red colour is from gas moving toward us more slowly. The background is an infrared image from the HAWK-I camera on ESO’s Very Large Telescope. The ALMA data only cover the region marked by the box. Credit:ALMA (ESO/NAOJ/NRAO), J. Bally/H. Drass et al.

    ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    ESO HAWK-I

    Groups of stars such as those in OMC-1 are born when a cloud of gas hundreds of times more massive than our Sun begins to collapse under its own gravity. In the densest regions, protostars form and begin to drift about randomly. Over time, this random motion can dampen, which allows some of the stars to fall toward a common center of gravity, usually dominated by a particularly large protostar.

    If these stars draw too close to each other before they drift away into the galaxy, violent interactions can occur. According to the researchers, such explosions are expected to be relatively short lived, with the remnants like those seen by ALMA lasting only centuries.

    “Though fleeting, protostellar explosions may be relatively common,” said Bally. “By destroying their parent cloud, as we see in OMC-1, such explosions may also help to regulate the pace of star formation in these giant molecular clouds.”

    Bally and his team observed this feature previously with the Gemini-South telescope in Chile.

    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile

    These earlier images, taken in the near infrared, reveal the remarkable structure of the streamers, which extend nearly a light-year from end to end.

    Hints of the explosive nature of this outflow were first uncovered in 2009 with the Submillimeter Array in Hawaii.

    CfA Submillimeter Array Mauna Kea, Hawaii, USA

    The new ALMA data, however, provide much greater clarity, unveiling important details about the distribution and high-velocity motion of the carbon monoxide (CO) gas inside the streamers. This helps astronomers understand the underlying force of the blast and the impact such events could have on star formation across the galaxy.

    “People most often associate stellar explosions with ancient stars, like a nova eruption on the surface of a decaying star or the even more spectacular supernova death of an extremely massive star,” Bally says. “ALMA has given us new insights into explosions on the other end of the stellar life cycle, star birth.”

    See the full article here .

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

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

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

    NRAO Small
    ESO 50 Large
    NAOJ

     
  • richardmitnick 2:13 pm on April 5, 2017 Permalink | Reply
    Tags: ALMA, , , Spring Cleaning in an Infant Star System   

    From ALMA: “Spring Cleaning in an Infant Star System” 

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

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

    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

    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
    Credit: ALMA (ESO/NAOJ/NRAO)/ Fedele et al.

    This image depicts the dusty disc encircling the young, isolated star HD 169142. The Atacama Large Millimeter/submillimeter Array (ALMA) imaged this disc in high resolution by picking up faint signals from its constituent millimetre-sized dust grains. The vivid rings are thick bands of dust, separated by deep gaps.

    Optimised to study the cold gas and dust of systems like HD 169142, ALMA’s sharp eyes have revealed the structure of many infant solar systems with similar cavities and gaps. A variety of theories have been proposed to explain them — such as turbulence caused by magnetorotational instability, or the fusing of dust grains — but the most plausible explanation is that these pronounced gaps were carved out by giant protoplanets.

    When solar systems form gas and dust coalesce into planets. These planets then effectively spring clean their orbits, clearing them of gas and dust and herding the remaining material into well-defined bands. The deep gaps seen in this image are consistent with the presence of multiple protoplanets — a finding that agrees with other optical and infrared studies of the same system.

    Observing such dusty protoplanetary discs with ALMA allows scientists to investigate the first steps of planet formation in a bid to unveil the evolutionary paths of these infant systems.

    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 2:52 pm on April 4, 2017 Permalink | Reply
    Tags: ALMA, , ,   

    From MIT: “Seeing black holes and beyond” 

    MIT News

    MIT Widget

    MIT News

    April 4, 2017
    Haystack Observatory

    A powerful new array of radio telescopes is being deployed for the first time this week, as the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile joins a global network of antennas poised to make some of the highest resolution images that astronomers have ever obtained.

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

    The improved level of detail is equivalent to being able to count the stitches on a baseball from 8,000 miles away.

    Scientists at MIT and other institutions are using a method called VLBI (Very Long Baseline Interferometry) to link a group of radio telescopes spread across the globe into what is, in effect, a telescope the size of our planet. Although the technique of VLBI is not new, scientists have just recently begun extending it to millimeter wavelengths to achieve a further boost in resolving power. And now, the addition of ALMA to global VLBI arrays is providing an unprecedented leap in VLBI capabilities.

    European VLBI

    The inclusion of ALMA was recently made possible through the ALMA Phasing Project (APP), an international effort led by the MIT Haystack Observatory in Westford, Massachusetts, and principal investigator Sheperd Doeleman, now at the Harvard–Smithsonian Center for Astrophysics.

    Before this project, the ALMA dishes worked with each other to make observations as a single array; now, the APP has achieved the synchronizing, or “phasing,” of up to 61 ALMA antennas to function as a single, highly sensitive radio antenna — the most antennas ever phased together. To achieve this, the APP team developed custom software and installed several new hardware components at ALMA, including a hydrogen maser (a type of ultraprecise atomic clock), a set of very-high-speed data reformatters, and a fiber optic system for transporting an 8 gigabyte-per-second data stream to four ultrafast data recorders (the Haystack-designed Mark6). The culmination of these efforts is an order-of-magnitude increase in the sensitivity of the world’s millimeter VLBI networks, and a dramatic boost in their ability to create detailed images of sources that previously appeared as mere points of light.

    “A great many people have worked very hard over the past several years to make this dream a reality,” says Geoff Crew, software lead for the APP. “ALMA VLBI is truly going to be transformative for our science.”

    One of the goals of these new technological innovations is to image a black hole. This month, two international organizations are making observations that will allow scientists to construct such an image for the very first time. And the portrait they’re attempting to capture is close to home: Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.

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

    So much data will be collected during the two observation periods that it’s faster to fly them to Haystack than it would be to transmit them electronically. Petabytes of data will be flown from telescopes around the world to Haystack for correlation and processing before images of the black hole can be created. Correlation, which registers the data from all participating telescopes to account for the different arrival times of the radio waves at each site, is done using a specialized bank of powerful computers. MIT Haystack is one of the few radio science facilities worldwide with the necessary technology and expertise to correlate this amount of data. Additional correlation for these sessions is being done at the Max Planck Institute for Radio Astronomy in Bonn, Germany.

    Two observing sessions are taking place. The GMVA (Global mm-VLBI Array) session will observe a variety of sources at a wavelength of 3 millimeters, including Sgr A* and other active galactic nuclei, and the EHT (Event Horizon Telescope) session will observe Sgr A* as well as the supermassive black hole at the center of a nearby galaxy, M87, at a wavelength of 1.3 millimeters. The EHT team includes researchers from MIT’s Haystack Observatory and MIT Computer Science and Artificial Intelligence Laboratory (CSAIL), working with the Harvard-Smithsonian Center for Astrophysics and many other organizations.

    Global mm-VLBI Array

    _______________________________________________________________________________________________________________________________________

    Event Horizon Telescope Array

    Event Horizon Telescope map

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

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

    ESO/APEX
    Atacama Pathfinder EXperiment (APEX)

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

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

    Caltech Submillimeter Observatory
    Caltech Submillimeter Observatory (CSO)

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

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

    Large Millimeter Telescope Alfonso Serrano
    Large Millimeter Telescope Alfonso Serrano

    CfA Submillimeter Array Hawaii SAO
    Submillimeter Array Hawaii SAO

    Future Array/Telescopes

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

    Plateau de Bure interferometer
    Plateau de Bure interferometer

    South Pole Telescope SPTPOL
    South Pole Telescope SPTPOL

    __________________________________________________________________________________________________________________________________

    “Several factors make 1.3 mm the ideal observing wavelength for Sgr A*,” according to APP Project Scientist Vincent Fish. “At longer observing wavelengths, the source would be blurred by free electrons between us and the galactic center, and we wouldn’t have enough resolution to see the predicted black hole shadow. At shorter wavelengths, the Earth’s atmosphere absorbs most of the signal.”

    The current observations are the first in a series of groundbreaking studies in VLBI and radio interferometry that will enable dramatic new scientific discoveries. Data from the newly phased ALMA array will also allow better imaging of other distant radio sources via improved data sampling, increased angular resolution, and eventually spectral-line VLBI — observations of emissions from specific elements and molecules.

    “Phasing ALMA has opened whole new possibilities for ultra high-resolution science that will go far beyond the study of black holes,” says Lynn Matthews, commissioning scientist for the APP. “For example, we expect to be able to make movies of the gas motions around stars that are still in the process of forming and map the outflows that occur from dying stars, both at a level of detail that has never been possible before.”

    The black hole images from the data gathered this month will take months to prepare; researchers expect to publish the first results in 2018.

    The MIT Haystack Observatory team of scientists includes Geoff Crew, Vincent Fish, Michael Hecht, Lynn Matthews, Colin Lonsdale, and Sheperd Doeleman (now at the Harvard-Smithsonian Center for Astrophysics).

    The organizations of the APP are: MIT Haystack Observatory (lead organization), Harvard–Smithsonian Center for Astrophysics, Joint ALMA Observatory (Chile), National Radio Astronomy Observatory (NRAO), Max Planck Institute for Radio Astronomy (Germany), University of Concepción (Chile), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), National Astronomical Observatory of Japan (NAOJ), and Onsala Observatory (Sweden).

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    MIT Seal

    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

    MIT Campus

     
  • richardmitnick 10:13 am on March 31, 2017 Permalink | Reply
    Tags: ALMA, , , , ,   

    From ALMA: “Attempting the Impossible: Taking the First Picture of a Black Hole” 

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

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

    The Atacama Large Millimeter/submillimeter Array (ALMA) joins for the first time the Global mm-VLBI Array (GMVA) and the Event Horizon Telescope (EHT), Earth-sized virtual observatories, which are made possible by an international collaboration of radio telescopes. One of the main drivers of this global collaboration is to study in detail the supermassive black hole at the center of our Milky Way. The GMVA will derive the properties of the accretion and outflow in the immediate surroundings of the Galactic Center, while the EHT will aim at imaging, for the very first time, the shadow of the black hole’s event horizon.

    The impressive line-up of participating telescopes stretch across the globe, from the South Pole to Europe to Hawaii, and, of course, Chile. ALMA with its 66 antennas, state-of-the-art receivers, its excellent site and southern location make it the largest and most sensitive, as well as a strategic component of both the GMVA and EHT. The observations will be done with the GMVA from April 1 to April 4, 2017, and with the EHT from April 5 to April 14, 2017.

    1
    This infographic details the locations of the participating telescopes of the Global mm-VLBI Array (GMVA), and the Event Horizon Telescope (EHT). Their goal is to image, for the very first time, the shadow of the event horizon of the supermassive black hole at the centre of the Milky Way, as well as to study the properties of the accretion and outflow around the Galactic Centre. Crédito: ESO/O. Furtak

    The outcome of these observations is eagerly awaited by the community as its scientific potential is incredibly exciting. To help understand better these forthcoming observations, ALMA and its partners have launched a blog series to explain what the GMVA and EHT projects are and the science behind them. The series will take you along an astronomical journey, providing insight into how cutting-edge research is done, describe the associated risks, and provide answers to questions such as: How do radiotelescopes see the Universe? Why are black holes so interesting? What do we know about the supermassive black hole at the center of the Milky Way?

    The first installment explains the GMVA and EHT projects in more detail and what they may see. You can read it here.

    2

    4
    ESO – ALMA and GMVA Observations in Cycle 4

    See the full article here .

    Event Horizon Telescope Array

    Event Horizon Telescope map

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

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

    ESO/APEX
    Atacama Pathfinder EXperiment (APEX)

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

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

    Caltech Submillimeter Observatory
    Caltech Submillimeter Observatory (CSO)

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

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

    Large Millimeter Telescope Alfonso Serrano
    Large Millimeter Telescope Alfonso Serrano

    CfA Submillimeter Array Hawaii SAO
    Submillimeter Array Hawaii SAO

    Future Array/Telescopes

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

    Plateau de Bure interferometer
    Plateau de Bure interferometer

    South Pole Telescope SPTPOL
    South Pole Telescope SPTPOL

    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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    NAOJ

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

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

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

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

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

    Tel: +81 422 34 3630

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

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

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

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

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

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

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

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

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

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


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

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

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


    NASA/ESA Hubble Telescope

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

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

    Notes

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

    Additional information

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

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

    See the full article here .

    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 10:34 am on March 15, 2017 Permalink | Reply
    Tags: ALMA, , , Cat's Paw Nebula (also known as NGC 6334), , , Protostar Blazes Bright, , Reshaping Its Stellar Nursery   

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

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

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

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

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

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


    CfA Submillimeter Array Mauna Kea, Hawaii, USA

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

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

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


    NASA/Spitzer

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

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

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

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

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

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

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

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

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

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


    Hartebeesthoek Radio Astronomy Observatory, located west of Johannesburg South Africa

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

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

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

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

    See the full article here .

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

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

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

    NRAO Small
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    NAOJ

     
  • richardmitnick 12:18 pm on March 14, 2017 Permalink | Reply
    Tags: ALMA, ALMA peers into the hearts of stellar nurseries, , , ,   

    From ALMA: “ALMA peers into the hearts of stellar nurseries” 

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

    13 March 2017
    No writer credit

    1

    With their spectacular glowing arms, grand spiral galaxies seem to get all the attention — but NGC 6822, a barred irregular dwarf galaxy, proves that regular spirals do not have a monopoly on galactic beauty. Also called Barnard’s galaxy, NGC 6822 is located in the constellation of Sagittarius just 1.6 million light-years away and is brimming with rich star formation regions.

    This new image is a composite of older observations made with the Wide Field Imager attached to the 2.2-metre MPG/ESO telescope at ESO’s La Silla Observatory and new data collected by the Atacama Large Millimeter/submillimeter Array (ALMA). The areas observed with ALMA are highlighted in the image and can be seen here in detail.


    MPG/ESO 2.2 meter telescope at Cerro La Silla, Chile


    ESO WFI LaSilla 2.2-m MPG/ESO telescope at La Silla

    The observations by ALMA reveal the structure of star-forming gas clouds in unprecedented resolution. Observations in our own galaxy have shown that stars form in the dense cores of giant clouds of molecular hydrogen gas, the only places where gas can become cold enough to collapse under its own gravity. These conditions also foster the formation of other molecules, such as carbon monoxide, which are an indispensable tool in helping astronomers to detect galactic molecular hydrogen gas.

    Until recently, astronomers have only been able to resolve star formation regions within the Milky Way — but now ALMA’s sharp sight provides a window into star formation in other galaxies. The analysis of the data revealed that, unlike in our own galaxy, the observed molecules are concentrated into small, dense cores of gas. This explains why it has been so hard to observe extragalactic star formation regions so far, especially in low mass, low metallicity galaxies. ALMA also found that the cores in NGC 6822 behave remarkably similarly to stellar nurseries in the Milky Way, indicating that the physics of star formation in these low-mass galaxies resemble that which we see in our own galaxy.

    Research paper by Schruba et al.

    See the full article here .

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

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

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

    NRAO Small
    ESO 50 Large
    NAOJ

     
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