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  • richardmitnick 1:28 pm on October 15, 2018 Permalink | Reply
    Tags: ALMA, , , , CI Tau, , Planet formation models, Protoplanetary discs,   

    From University of Cambridge: “Giant planets around young star raise questions about how planets form” 

    U Cambridge bloc

    From University of Cambridge

    15 Oct 2018
    Sarah Collins
    sarah.collins@admin.cam.ac.uk

    1
    Artist’s impression of CI Tau. Credit: Amanda Smith, Institute of Astronomy

    Researchers have identified a young star with four Jupiter and Saturn-sized planets in orbit around it, the first time that so many massive planets have been detected in such a young system. The system has also set a new record for the most extreme range of orbits yet observed: the outermost planet is more than a thousand times further from the star than the innermost one, which raises interesting questions about how such a system might have formed.

    The star is just two million years old – a ‘toddler’ in astronomical terms – and is surrounded by a huge disc of dust and ice. This disc, known as a protoplanetary disc, is where the planets, moons, asteroids and other astronomical objects in stellar systems form.

    The star was already known to be remarkable because it contains the first so-called hot Jupiter – a massive planet orbiting very close to its parent star – to have been discovered around such a young star. Although hot Jupiters were the first type of exoplanet to be discovered, their existence has long puzzled astronomers because they are often thought to be too close to their parent stars to have formed in situ.

    Now, a team of researchers led by the University of Cambridge have used the Atacama Large Millimeter/submillimeter Array (ALMA) to search for planetary ‘siblings’ to this infant hot Jupiter.

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

    Their image revealed three distinct gaps in the disc, which, according to their theoretical modelling, were most likely caused by three additional gas giant planets also orbiting the young star. Their results are reported in The Astrophysical Journal Letters.

    The star, CI Tau, is located about 500 light years away in a highly-productive stellar ‘nursery’ region of the galaxy. Its four planets differ greatly in their orbits: the closest (the hot Jupiter) is within the equivalent of the orbit of Mercury, while the farthest orbits at a distance more than three times greater than that of Neptune. The two outer planets are about the mass of Saturn, while the two inner planets are respectively around one and 10 times the mass of Jupiter.

    The discovery raises many questions for astronomers. Around 1% of stars host hot Jupiters, but most of the known hot Jupiters are hundreds of times older than CI Tau. “It is currently impossible to say whether the extreme planetary architecture seen in CI Tau is common in hot Jupiter systems because the way that these sibling planets were detected – through their effect on the protoplanetary disc – would not work in older systems which no longer have a protoplanetary disc,” said Professor Cathie Clarke from Cambridge’s Institute of Astronomy, the study’s first author.

    According to the researchers, it is also unclear whether the sibling planets played a role in driving the innermost planet into its ultra-close orbit, and whether this is a mechanism that works in making hot Jupiters in general. And a further mystery is how the outer two planets formed at all.

    “Planet formation models tend to focus on being able to make the types of planets that have been observed already, so new discoveries don’t necessarily fit the models,” said Clarke. “Saturn mass planets are supposed to form by first accumulating a solid core and then pulling in a layer of gas on top, but these processes are supposed to be very slow at large distances from the star. Most models will struggle to make planets of this mass at this distance.”

    The task ahead will be to study this puzzling system at multiple wavelengths to get more clues about the properties of the disc and its planets. In the meantime, ALMA – the first telescope with the capability of imaging planets in the making – will likely throw out further surprises in other systems, re-shaping our picture of how planetary systems form.

    The research has been supported by the European Research Council.

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

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  • richardmitnick 9:14 am on October 8, 2018 Permalink | Reply
    Tags: ALMA, , , , , , , When Is a Nova Not a ‘Nova’? When a White Dwarf and a Brown Dwarf Collide   

    From ALMA: “When Is a Nova Not a ‘Nova’? When a White Dwarf and a Brown Dwarf Collide” 

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

    From ALMA

    8 October, 2018

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

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

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

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

    1
    ALMA image of CK Vulpeculae. New research indicates that this hourglass-like object is the result of the collision of a brown dwarf and a white dwarf. Credit: ALMA (ESO/NAOJ/NRAO)/S. P. S. Eyres

    Using the Atacama Large Millimeter/submillimeter Array (ALMA), an international team of astronomers found evidence that a white dwarf (the elderly remains of a star like the Sun) and a brown dwarf (a failed star without the mass to sustain nuclear fusion) collided in a short-lived blaze of glory that was witnessed on Earth in 1670 as Novasub Capite Cygni (a New Star below the Head of the Swan), which is now known as CK Vulpeculae.

    2
    This chart of the position of a nova (marked in red) that appeared in the year 1670 was recorded by the famous astronomer Hevelius and was published by the Royal Society in England in their journal Philosophical Transactions. New observations made with ALMA and other telescopes have now revealed that the star that European astronomers saw was not a nova, but a much rarer, violent breed of stellar collision. It was spectacular enough to be easily seen with the naked eye during its first outburst, but the traces it left were so faint that very careful analysis using submillimetre telescopes was needed before the mystery could finally be unravelled more than 340 years later.

    In July of 1670, observers on Earth witnessed a “new star,” or nova, in the constellation Cygnus. Where previously there was dark sky, a bright pinprick of light appeared, faded, reappeared, and then disappeared entirely from view. Modern astronomers studying the remains of this cosmic event initially thought it heralded the merging of two main sequence stars – stars on the same evolutionary path as our Sun.

    New observations with ALMA point to a more intriguing explanation. By studying the debris from this explosion, which takes the form of dual rings of dust and gas resembling an hourglass with a compact central object, the researchers concluded that a brown dwarf – a so-called failed star without the mass to sustain nuclear fusion — merged with a white dwarf.

    “It now seems what was observed centuries ago was not what we would today describe as a classic ‘nova.’ Instead, it was the merger of two stellar objects, a white dwarf and a brown dwarf. When these two objects collided, they spilled out a cocktail of molecules and unusual isotopes, which gave us new insights into the nature of this object,” said Sumner Starrfield, an astronomer at Arizona State University and co-author on a paper appearing in the Monthly Notices of the Royal Astronomical Society.

    According to the researchers, the white dwarf would have been about ten times more massive than the brown dwarf, though much smaller in size. As the brown dwarf spiraled inward, intense tidal forces exerted by the white dwarf would have ripped it apart. “This is the first time such an event has been conclusively identified,” remarked Starrfield.

    Since most star systems in the Milky Way are binary, stellar collisions are not that rare, the astronomers note. The new ALMA observations reveal new details about the 1670 event. By studying the light from two, more-distant stars as it shines through the dusty remains of the merger, the researchers were able to detect the telltale signature of the element lithium, which is easily destroyed in the interior of a main sequence star, but not inside a brown dwarf.

    “The presence of lithium, together with unusual isotopic ratios of the elements carbon, nitrogen, and oxygen point to material from a brown dwarf star being dumped on the surface of a white dwarf. The thermonuclear ‘burning’ and an eruption of this material resulted in the hourglass we see today,” said Stewart Eyres, Deputy Dean of the Faculty of Computing, Engineering and Science at the University of South Wales and lead author on the paper.

    Intriguingly, the hourglass is also rich in organic molecules such as formaldehyde (H2CO) and formamide (NH2CHO), which is derived from formic acid. These molecules would not survive in an environment undergoing nuclear fusion and must have been produced in the debris from the explosion. This lends further support to the conclusion that a brown dwarf met its demise in a star-on-star collision with a white dwarf.

    Additional Information

    “ALMA Reveals the Aftermath of a White Dwarf—Brown Dwarf Merger in CK Vulpeculae,” Steward Eyres, University of Central Lancashire; Aneurin Evans, Keele University; Albert Zijlstra, Adam Avison, University of Manchester; Robert Gehrz, Charles Woodward, University of Minnesota; Marcin Hajduk, University of Warmia and Mazury; Sumner Starrfield, Arizona State University; Shazrene Mohamed, South African Astronomical Observatory; and R. Mark Wagner, The Ohio State University.

    See the full article here .

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    Stem Education Coalition

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

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

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    ESO 50 Large
    NAOJ

     
  • richardmitnick 9:30 pm on October 2, 2018 Permalink | Reply
    Tags: ALMA, , , , , , , ,   

    From Science: “Cosmic conundrum: The disks of gas and dust that supposedly form planets don’t seem to have the goods” 

    AAAS
    From Science Magazine

    1
    Artist’s illustration of the protoplanetary disk surrounding a young star. JPL-Caltech/NASA

    Astronomers have a problem on their hands: How can you make planets if you don’t have enough of the building blocks? A new study finds that protoplanetary disks—the envelopes of dust and gas around young stars that give rise to planets—seem to contain orders of magnitude too little material to produce the planets.

    “This work is telling us that we really have to rethink our planetary formation theories,” says astronomer Gijs Mulders of the University of Chicago in Illinois, who was not involved in the research.

    Stars are born from colossal clouds of gas and dust and, in their earliest stages, are surrounded by a thin disk of material. Dust grains within this halo collide, sometimes sticking together. The clumps build up into planetary cores, which are big enough to gravitationally attract additional dust and gas, eventually forming planets.

    But many details about this process remain unknown, such as just how quickly planets arise from the disk, and how efficient they are in capturing material. The disks, surrounded by an obscuring haze of gas and dust, are difficult to observe. But radio telescopes can penetrate the haze and investigate young stars. The brightness of radio waves emitted by dust in the disk can be used to give a reasonable estimate of its overall mass.

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

    The Atacama Large Millimeter Array (ALMA), a radio observatory in the Atacama Desert in Chile, has made it far easier to study protoplanetary disks. In the new study, astronomers led by Carlo Manara of the European Southern Observatory in Munich, Germany, used ALMA to compare the masses of protoplanetary disks around young stars between 1 million and 3 million years old to the masses of confirmed exoplanets and exoplanetary systems around older stars of equivalent size. The disk masses were often much less than the total exoplanet mass—sometimes 10 or 100 times lower, the team will report in an upcoming paper in Astronomy & Astrophysics.

    Although such findings have been reported before for a few star systems, the study is the first to point out the mismatch over several hundred different systems. “I think what this work does is really set this as a fact,” Manara says.

    It is possible that astronomers are simply looking at the disks too late. Perhaps some planets form in the first million years, sucking up much of the gas and dust, Manara says. ALMA has found that some extremely young stars, such as the approximately 100,000-year-old HL Tauri, already have ringlike gaps in their disks, potentially indicating that protoplanets are sweeping up material inside of them.

    “But if you solve one problem, you end up with another,” says astronomer Jonathan Williams of the University of Hawaii Institute for Astronomy in Honolulu, who was also not involved in the work. If planetary cores form early, when so much material remains in the disk, nothing would stop them from ballooning into Jupiter-size behemoths. Yet the emerging census of exoplanets shows that most are Earth- or Neptune-size worlds.

    Williams favors the idea that current telescopes are simply missing some of the material. ALMA’s wavelengths are tuned to best see the smallest bits of dust. But a great deal of mass, perhaps as much as 10 times what’s been observed, could be hidden in the form of pebbles, which are slightly too big to show up in such investigations. A proposed upgrade to the Very Large Array, a radio telescope in New Mexico, should be able to spot such hidden debris, perhaps accounting for some of the missing material.

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

    One final possibility is that protoplanetary disks are somehow sucking in additional material from the surrounding interstellar medium. Manara says some recent simulations show young stars drawing in fresh material for much longer periods of time than previously believed. He hopes that observations of the earliest stages of star formation from the upcoming Square Kilometer Array or James Webb Space Telescope will help researchers decide between these different hypotheses.

    NASA/ESA/CSA Webb Telescope annotated

    See the full article here .


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  • richardmitnick 10:02 pm on September 24, 2018 Permalink | Reply
    Tags: ALMA, People Working for ALMA (2) Computing Work Connects Machines as well as People   

    From ALMA: “People Working for ALMA (2) Computing Work Connects Machines as well as People” 

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

    From ALMA

    ALMA produces huge amounts of observation data from gigantic hardware systems. Remarkable ALMA results achieved by astronomers are always supported by ALMA computing teams. Software development is indispensable in making all the machines work in perfect order and also in producing images of astronomical objects from enormous amounts of data. This series of interviews features people working for ALMA. In the second installment of the series, we interviewed Associate Professor George Kosugi, who leads the NAOJ ALMA computing team.

    “What is Computing All About?”

    — Let’s start with a very basic question; what is computing all about?

    Kosugi: To put it shortly, ALMA computing team conducts various software developments for making the ALMA telescope actually work.

    — You are making software, not hardware like computer devices.

    Kosugi: Right. The word “software” probably reminds most people of programs available on personal computer.

    1
    George Kosugi (Associate Professor at the NAOJ Chile Observatory)

    — Games and applications.

    Kosugi: Exactly. Even if we have a computer like PC or smartphone, we cannot use it without software. Similarly, ALMA has supercomputers called “Correlator” in Chile. Enhanced computing capability is required for ALMA that processes enormous amounts of data to produce images of astronomical objects from data collected by up to 66 antennas. And such processing is carried out by the correlators. Our ALMA computing team develops software to control the Correlator and other types of software too.

    — What other types of software are you making?

    Kosugi: ALMA has roughly two types of software: one is “online software” which is used to operate observing instruments and systems in real time for actual observations. And another is “offline software” which is used before or after observation. For example, online software includes control software to make up to 66 antennas work in perfect order and software to send commands to the Receiver that has a measurement function of radio waves collected by antennas. Also, online software includes software to operate the Correlator that processes data from multiple antennas and software to store the data processed by the Correlator into the archives.

    2
    System diagram of ALMA. Various instruments including antennas, receivers, correlators, and data archive work in unison. Credit: ALMA (ESO/NAOJ/NRAO)

    “Computing Builds Framework of ALMA”

    — On the other hand, what is the offline software?

    Kosugi: To explain it, we need to begin with the introduction of the flow of observation with ALMA. First of all, researchers prepare observing proposals and submit them to the ALMA Observatory. When the proposal is accepted after the review, researchers describe various setting parameters for telescope and instrument in a set of electric files (so-called “Phase 2 Programs”) and send the Programs to the database. And then, ALMA operators execute the Phase 2 Programs on the ALMA control computers to perform observations. In this process, various pieces of offline software are used: such as software to prepare observing proposals; software to support the proposal review; and software to prepare Phase 2 Programs.

    — I see.

    Kosugi: Offline software is used again after an observation has been finished and the data has been archived. ALMA staffs process the data and the resulting data is back to the archive. Then finally, the data is sent to the researcher who submitted the observing proposal. The software for data processing and archiving are also categorized as offline software. Each piece of function required for the observation flow is developed by the computing team.

    3
    ALMA observation sequence and software used in each step. Credit: ALMA (ESO/NAOJ/NRAO)

    — It looks like computing is building the framework of the ALMA observatory.

    Kosugi: Most people think of astronomers as the image of people working for ALMA. On the other hand, our computing work is not visible to the public because we are playing “background” roles. I hope these interviews will help highlight the importance of computing and raise the motivation of the computing team members.

    — How many people are working in your computing team currently?

    Kosugi: In ALMA as a whole, three regions have each computing team respectively in Japan, North America, and Europe and one computing team in Chile. There are approximately 80 members in total all over the world, of which nearly 20 members belong to the Japanese computing team. I lead the Japanese computing team as a manager.

    — Does each regional team have different tasks?

    Kosugi: Main task assigned to the Japanese team is software development to control the Atacama Compact Array (ACA, as known as the Morita Array) and its Correlator. Also we implement some tasks jointly with other regional teams in the development of analysis software and archive software as well as in the tests of software.

    — ALMA has already started observations but is the development still in progress?

    Kosugi: ALMA has been continuously improving its capability by installation of new observing instruments and addition of new observing modes. Even for the Correlator mentioned earlier, discussion for the next generation development has already started. Our computing team has also been continuing development to catch up with these ongoing developments. For example, when a new observing mode is added, such function needs to be included in software. And, we need debugging too. Bugs have never been worked out in such a large scale software. In addition to the development of software functions, we are always conducting development while thinking about how to improve the speed and efficiency of software. If data analysis needs to be faster, we try to make it better by algorithm improvement or parallelization of analysis software.

    “Engaged in Software Development in Subaru and ALMA”

    — You were originally an astronomer, not a specialist in computing or IT.
    Kosugi: Right. I developed a system called “Spectro-Nebulagraph” as one of a research theme of my doctoral thesis. Originally I developed it for studying active galaxies, and it gave me a chance to be engaged in computing.

    — What was it?

    Kosugi: There is an instrument called “spectro-heliograph” to observe the Sun. It can take particular color images of the whole surface of the Sun by scanning the Sun’s disk with continuously moving slit. By applying the method of spectro-heliograph to observations of galaxies and nebulae, I developed Spectro-Nebulagraph. The system was connected via computer network to the 188-cm Optical Telescope at Okayama Astrophysical Observatory, a spectrograph, and a CCD camera and operated in coordination with all these systems to obtain data. I made this system together with Dr. Hiroshi Ohtani who was my supervisor at the time and Dr. Toshiyuki Sasaki at Okayama Astrophysical Observatory.

    4
    Spectro-Nubulagraph and its development/research team (photo taken a quarter-century ago). From right, Kosugi, Professor Sasaki, and the forth is Professor Ohtani. The light-blue box above the team is the spectrograph and the gold-colored tube is the CCD camera. Credit: NAOJ

    — So, the development of the system itself was also a research theme of your doctoral thesis as well as scientific results. Were you familiar with computing and systems?

    Kosugi: I was a member of math club at high school and had opportunities to use computers. When I entered university, high-performance personal computers like PC-9800 series (a product of current NEC) were becoming available. Then, I started to create games using it and occasionally created astrology application software for an attraction at the school festival. As its extension, I started working on the control system of telescopes and observing instruments.
    In the early stage of personal computers, Spectro-Nebulagraph was quite a novel system in the world. It was the time a quarter of a century ago when the network was barely used by the general public. Under such circumstances, we made an observing system organically connected with observing instruments, CCD camera, and computers in a form of a distributed system. It surely affected the design concept of the Subaru Telescope’s observing system later.

    — After you wrote your doctoral thesis, you were hired by NAOJ and assigned computing related work at the Subaru Telescope.


    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA,4,207 m (13,802 ft) above sea level

    Kosugi: Yes. I was transferred to Hawaii in 1997, and engaged in the work to connect the control software for the telescope and observing instruments to the observing control software that manages the whole system, as well as commissioning of the telescope and observing instruments and their evaluation tests. In fact, I was already working at the NAOJ in Mitaka from the last part of my Ph.D. program and joined in the discussions of the concept design of Subaru software system together with Dr. Sasaki as mentioned earlier and other members at the NAOJ.

    — Then, you were transferred to ALMA.

    Kosugi; Yes, it was in 2005. Subaru has already finished its commissioning and started producing results. I was conducting various astronomical researches with Subaru. In the previous year 2004, Japan officially participated in the ALMA construction project and they were going to create regional computing teams respectively in Japan, North America, and Europe to develop dedicated software for ALMA. And, I was invited to join ALMA by the late Dr. Ko-ichiro Morita and Dr. Ken’ichi Tatematsu (current director of the Nobeyama Radio Observatory of NAOJ) and I decided to move to ALMA.

    — You are also working for the construction project of the Thirty Meter Telescope (TMT: next generation large scale telescope of 30 meters in diameter).

    TMT-Thirty Meter Telescope, proposed and now approved for Mauna Kea, Hawaii, USA4,207 m (13,802 ft) above sea level

    Kosugi: ALMA has become a fully-fledged observatory producing an increasing number of scientific results. I originally came from the field of optical/infrared observational astronomy. While new scientific results are very attractive to me, I also enjoy very much working for a new project in a hectic start-up period with a lot of valuable experience.

    “ALMA Software Separately Developed by Three Regions”

    — Is there any difference in computing work between Subaru and ALMA?

    Kosugi: While Subaru is a single telescope, ALMA consists of 66 antennas that need to be synchronized during observations. A big difference is the need to consider the timing of synchronization for ALMA. Furthermore, for example, ALMA has dedicated software for observing preparation called “ALMA Observing Tool” which is used to accurately set up the observation plan with ALMA.
    Although Subaru was built overseas, it was basically a Japanese project that was made in “All Japan”. On the other hand, the development of ALMA is geographically separated in Japan, North America, and Europe. This is another characteristic of ALMA.

    — We heard that it was not easy at all to hold a teleconference.

    Kosugi: Right. We usually had teleconferences around midnight in Japan time. It was daytime in Chile, early morning in the U.S. and early evening in Europe. They were working during regular business hours, but we were forced to do late-night overtime in Japan (laugh).

    — We also heard that ALMA antennas and receivers were developed separately by Japan, North America, and Europe, and it worked well in making a better product through friendly competition. Was the situation similar in computing too?

    Kosugi: In computing, I felt like we were jointly making one product in collaboration of regional partners. Competition rarely happened…no, it didn’t happen at all. Any competition costs money, because they have to make a different plan and implement it separately. Computing teams took a different approach: we divided work and clearly defined the interfaces between respective systems to make one product in collaboration of regional teams, rather than competition.

    “Computing Requires Knowledge in Astronomy?”

    — You told you were originally an astronomer, but do you have people who have originally specialized skills in IT in your team members?

    Kosugi: Many. Some of them joined us after a career as an IT specialist at private companies.

    — What is the advantage or good point in working as a computing specialist at ALMA or in other astronomical fields, compared to IT or computing jobs in the private sector?

    Kosugi: I don’t know well about IT jobs at private companies because I’ve never been there. However, from the perspective of my experience, ALMA is one and only telescope in the world and the world’s highest performance telescope at submillimeter wavelengths. Software to operate such a unique telescope is also one and only in the world. One of the biggest appeal is the opportunity to create such unique software.
    Another advantage is that we have no competitors, since there is no product like ALMA. It may apply only to computing though. In the consumer product market, we have to work hard to beat competitors.

    — Competition not only for quality but also competition probably for time and costs.

    Kosugi: Right. Of course, we always keep time and costs in mind for ALMA too, but we are not working hurriedly all the time. We can have time to sit down and think about how to create a novel and innovative product. Creative ideas will never be generated when you are pressured or in a hurry. In this sense, working in this field allows us to expand our possibility and reflect more deeply on ourselves. This approach doesn’t necessarily fit for everybody but quite a number of software developers, I guess, will enjoy such experience.

    — Is knowledge in astronomy required for a computing specialist in ALMA?

    Kosugi: It depends on the fields. For example, the control of the antennas and the correlator doesn’t require specialized knowledge of astronomy. It will be sufficient to learn it as needed. On the other hand, for the development of data analysis software, our development team members mostly have obtained Ph.D. in astronomy. Development work will be easier for a person who has astronomical backgrounds, because he or she can see the purpose of the analysis and what analysis should be made by feeling. Having said that, most part can be developed without knowledge in astronomy and there are some specific tasks that may be better assigned to a person who came from the private IT sector with detailed knowledge of the latest technology trend, such as realizing faster processing and parallelization of programs.

    — ALMA and other astronomical fields need more people who have specialized skills in IT.

    Kosugi: I think so. For me, another attraction in computing work on astronomical project such as Subaru and ALMA is to have opportunities to see the very first image of the universe during computing tests before it became open to the public. It’s very exciting to see an image that nobody has ever seen before.

    — You can see the very first picture of the universe exclusively before everyone else.

    Kosugi: True. In the case of ALMA, we don’t know what image it will be just after the data was collected by antennas or even after the data was processed by the correlator. Only the person to be given the opportunity to see the first picture will be the one who has developed the data analysis software because the person has a task to analyze the data and produce an image for testing. Since target objects observed by ALMA are mostly astronomical objects that can be seen only with ALMA, it will be very thrilling experience for someone who has studied astronomy.

    “Power to Connect Creators of World’s Leading Technologies”

    — Lastly, can you tell us what fascinated you most about computing throughout your experience in this field over years?

    Kosugi: The best part of computing is maybe building connections with various things, which is also rephrased as creating “bonds” using a buzzword of recent years.

    — Bonds. We didn’t expect to hear the word with a topic of computing.

    Kosugi: No matter how advanced functions a telescope or any other hardware has, it only can serve as a case without software. While the performance limit of each device is determined by hardware, it will be a role of software to draw the best performance from the device and connect it with other devices to work it as a system in actual operations. As I used this analogy somewhere else, if each device is the warp, software is the weft that connects them all together to complete a textile, which is called a system.

    — Good example. Very easy to understand.

    Kosugi: As I already mentioned earlier, components of ALMA such as the antenna, receiver, and correlator are all state-of-the-art technologies. Touching these components gives us a sense of excitement and raise our motivation. It’s enjoyable enough to get deeper understanding of leading-edge technologies and to connect them as a system but furthermore in that process, we can meet people who created the world’s highest performance equipment. We also have discussions with them on how to design software to control various pieces of equipment. It’s a very exciting part of our work to be able to connect with creators of leading-edge technologies, since it can broaden our perspective and knowledge base.

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    During antenna control tests developed by Japan. Control software is indispensable for antenna operations. Credit: NAOJ

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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    NAOJ

     
  • richardmitnick 9:35 pm on September 24, 2018 Permalink | Reply
    Tags: ALMA, , , , , People, People Working for ALMA (3) Visualize the invisibles: Professional in Data Analysis to Create Image from Radio Data,   

    From ALMA: “People Working for ALMA (3) Visualize the invisibles: Professional in Data Analysis to Create Image from Radio Data” 

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

    From ALMA

    ALMA is used by astronomers all over the world. After ALMA observations have been carried out, the data is firstly processed by experts from the ALMA Support Centers, and then the processed data is delivered to astronomers together with radio image data. In an analogy of cooking, the support team is like an assistant who precooks the ingredients. It releases astronomers from complicated processing work and helps them concentrate on their research in exploring the mysteries hidden in the observation data. In the third installment of this series, we interviewed Hiroshi Nagai at NAOJ, who led the Japanese Data Analysis Team, and had talks about the background support work for producing remarkable scientific results with ALMA (Note: as of the date of the interview. Currently Kouichiro Nakanishi takes the leadership.).

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    Hiroshi Nagai, Project Associate Professor at the NAOJ Chile Observatory. Credit: NAOJ

    What is “Seeing Radio Waves”?

    — I’d like to start from a very basic question. What does it mean by “seeing radio waves” or “seeing at radio wavelengths”?

    Nagai: This is a question we are asked very often. It must be a difficult concept to understand for the general public.

    ── It feels more like “hearing” radio waves, rather than “seeing”.

    Nagai: Thinking of a mobile phone or a radio, it looks like we are “listening” to them. Also, I remember a scene in the old movie “Contact” where the leading character was hearing radio waves coming from the space.

    — It’s a science-fiction movie starring Jodie Foster as an astronomer.

    Nagai: Right. The leading character receives radio signals sent from an extraterrestrial civilization and listens to them with a headset. But, actually, we astronomers do not listen to radio waves (laugh).

    — What are astronomers actually doing then?

    Nagai: Let’s put aside the topic of radio telescopes for now. When we “see” things with eyes or with camera, we are getting basically two types of information: one is intensity of light and another is color. Technically speaking, color is the wavelength of light.
    Now, putting aside the color, imagine a black and white photo. Each pixel of the photo represents the intensity of light and forms a grayscale image as a whole. Radio observation does exactly the same thing, because it visualizes the intensity of radio waves coming from the universe as an image. Radio waves are invisible to the human eye and we don’t know what color the emission really is, but we can produce a radio image by showing the intensity of radio emission of each pixel in grayscale.

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    A photo of a spiral galaxy captured with the Subaru Telescope. In an enlarged portion, we can see pixels. The scaling represents the intensity of light. Credit:NAOJ

    — Exactly the same as visible light. Very easy to understand.

    Nagai: As mentioned earlier, the difference in color is the difference in wavelength. The same is true in radio waves. The role of the radio telescope is to measure the intensity and wavelengths (equivalent to colors) of radio emissions coming from the universe to create two-dimensional image.

    — I think I got the meaning of “seeing at radio wavelengths”.

    Nagai: It might sound simple, but we actually have complicated process in producing images from radio data received with a telescope. In particular, ALMA consists of 66 parabolic antennas that work as a single giant virtual radio telescope. This system is called “interferometer” and requires very difficult and delicate data handling. That’s why our team conducts reduction and imaging of the data.

    “Data reduction team maximizes the scientific output from ALMA”

    — In ALMA, obtained data is delivered to researchers after the data reduction team finishes reduction and imaging. What is the situation with other telescopes?

    Nagai: As far as I know, ALMA is the only ground-based telescope that reduces all the data and delivers them to researchers, at least in the field of radio telescopes. In general, researches receive raw data obtained by the telescope. That policy is something like “Observation was done. Wishing your data analysis goes well. Good luck!” (laugh)

    — Why does ALMA deliver processed data including even image data?

    Nagai: The difference between raw data and processed data can be likened to a whole tuna and tuna fillets. If a whole tuna is delivered to your home, you will be at a loss of what to do with it. But if you receive processed tuna fillets, you know how to cook with them. In short, we are doing a cutting part of a whole fish.

    — The analogy of a tuna is very easy to understand.

    Nagai: It is quite difficult to handle raw ALMA data especially for someone who has no specialized skills in the radio interferometer. We have to avoid situations where researchers have troubles in writing papers with low-quality observation data or due to a lack of knowledge of how to create images. One of our aims is to reduce such situations and make ALMA available to a wide range of people including those who are not experts of the radio interferometer. To encourage the efficient use of ALMA data not only by the proposers of observations but also by other researchers, we need to provide processed data instead of raw data and make it available in the archives.

    — Certainly, processed data can be handled more easily by other researchers.

    Nagai: Since an enormous amount of money has been invested in ALMA, it is important to promote efficient and extensive use of obtained data by many researchers. If observation data together with image data is publicly available in the archives, researchers can start their work easily. I think ALMA’s fundamental policy is to encourage the use of valuable ALMA data by a wide range of people so that more and more great scientific results will be produced.

    3
    Credit:NAOJ

    “Calibration” of Observation Data”

    — Could you explain the actual data processing in more detail?

    Nagai: First, we need to “calibrate” the data. Calibration means data correction. Imagine we have radio data received by Antenna A and another radio data received by Antenna B which is remotely located. When the two waves are synthesized, we can have “interference” of the waves in technical terms. We need to synthesize the two waves detected precisely at the same time with each antenna, but if the sky above Antenna B is cloudy, there will be a slight delay in the arriving time of the radio wave that travels through water vapor in the air. Part of our calibration work is to calculate the difference of arriving time and perform data correction.

    — How do you know the conditions where radio waves travel though clouds?

    Nagai: We have various methods. For example, we use an instrument called “water vapor radiometer” installed in each antenna. The water vapor radiometer is designed to measure the amount of water vapor in the sky. We can calibrate the delay of radio waves using this data. Another method is to calculate the delay of radio waves from the results of actual observations of bright radio sources in the sky. If we have a delay, the obtained image of the object becomes blurry. Then, we conduct actual observations of an object that only looks like a point source and based on the obtained image, we correct blur.

    3
    When there are clouds of water vapor in the sky, they block the paths of radio waves and cause delays. It results in distortion of a produced image because of failed synthesis of radio waves received by multiple antennas. Credit: NAOJ

    — What else will be done by calibration other than studying the delay of radio waves?

    Nagai: We also perform calibration of radio intensity. It is not so easy to determine the intensity of radio waves emitted from astronomical objects. Because, ALMA has an extremely large and complicated system. The recorded signal passes all the way from the antenna, receiver, digital backend, optical fiber, to the correlator. But what astronomers want to know is how strong the radio emission was before entering the telescope. So, when we detect different intensity of radio wave in different epochs, we need to figure out whether the radio intensity of the object has really changed or it is affected by weather or instrument conditions of the telescope.

    — How can you identify the cause?

    Nagai: We use certain astronomical objects, whose radio intensities have already been known, as standard “calibration sources” for reference. Based on the reference value, we calibrate the radio intensity of the target object afterwards.

    “How to Decide the Colors of Astronomical Images?”

    — After calibrating the data received by ALMA, images will be created.

    Nagai: Right. Imaging is also carried out by our team.

    — You said that radio waves are invisible to the human eye and we don’t know what color the emission really is. But, we see colorful images in press releases. How do you color images?

    Nagai: To tell the truth, we have no specific rules in coloring. There is a standard color allocation method provided by image visualization software, and we follow that method in principle.

    — I see. Does the standard method use red colors for longer wavelengths and blue colors for shorter wavelengths as we can see with the naked eye?

    Nagai: We rarely allocate colors according to the wavelength. What we often use is “rainbow color” which is applied not according to the wavelengths but the radio intensity. As the intensity increases, the color becomes more reddish and as it decreases, the color becomes more purplish.

    — Are you saying that researchers don’t care about what colors are used for imaging?

    Nagai: Not much. They are more interested in the difference of radio intensity. So, we often use rainbow color so as to show the difference of radio intensity more clearly, instead of trying to make it look beautiful, even though we have no limitations set by the data format in choosing colors for images created by the analysis team.

    — Do you use different color allocation methods in creating images for press releases to be released to the public?

    Nagai: Yes, we do care more about creating visually appealing images for press releases.

    5
    HL Tauri, observed with ALMA, shown with different colors. A variety of color allocation methods are available depending on the purpose of use and the points to be emphasized.
    Credit: ALMA (ESO/NAOJ/NRAO)

    “Automatic Analysis System “Pipeline” Newly Introduced”

    — Do you perform calibration and imaging manually by each observation?

    Nagai: Actually, we have a system called “Pipeline” to automatically perform calibration and imaging.

    — Is that a name of software?

    Nagai: Maybe more appropriate to say it is a “system” rather than software. We named it “Pipeline” because it automatically performs a series of processing from calibration to imaging just by feeding raw data. However, it didn’t work well initially and involved a lot of manual works. We had to keep proposers waiting long until they received their observation data

    — You must have had a hard time.

    Nagai: Yes, it was very hard at the beginning, but there was a dramatic improvement over the last year. As the development of Pipeline has progressed, we have less and less errors. The amount of our manual work was reduced substantially.

    — Is analysis work carried out by each region?

    Nagai: Yes, analysis work has been conducted separately in Chile, East Asia, North America, and Europe.

    “With Pride in Working for the World’s leading Telescope”

    — I guess you have difficulties in your data analysis work, but what is the fascinating part about your work?

    Nagai: ALMA is the world’s leading telescope that has been producing more and more new scientific results and making amazing discoveries in exploration of mysteries of the universe. As a staff member of ALMA, I feel it very important to make efforts every day to ensure the delivery of high-quality data to the public. So, I am glad that I can contribute to the data analysis work, which is very rewarding. As data analysis requires profound knowledge of the radio interferometer, we are all proud of making professional contributions to this important work as members of the East Asian ALMA Regional Center.

    — You are working with the spirit of professionalism.

    Nagai: Also, through data analysis work, I get to know more people. ALMA users include a wide range of researchers from various fields of study. I used to work mostly with people of the same field, now I have more opportunities to be connected with researchers who have totally different expertise. And I have more contact with researchers of other fields in answering questions about data analysis and such contact sometimes leads to collaborative research. I enjoy these kinds of exchanges with new people very much.

    — We heard your specialty is study of black holes.

    Nagai: Yes. I specialized in radio observation of jets in supermassive black holes.

    — As a researcher, would you like to get back to your research when all the data analysis works were transferred to Chile?

    Nagai: Researchers are wishing to keep doing research, so I dream about devoting 100% of my time and energy to my research. However, considering the importance of large-scale astronomical projects like ALMA for the advancement of astronomy, I understand specialized manpower will be continuously needed. So, taking the advantage of my experience with ALMA, I would like to utilize what I have learnt so far for the development of astronomy. I think it would be great if I could achieve a good balance between my project work and research and make even small portion of time for my research.

    6
    Hiroshi Nagai (Project Associate Professor at the NAOJ Chile Observatory)
    Obtained Ph.D. in SOKENDAI (the Graduate University for Advanced Studies) in 2007. Specialized in observational study of the circumference of supermassive black holes at the galactic centers and high-speed gas flows (jets) emanating from supermassive black holes. After obtained Ph.D, engaged in researches at the National Astronomical Observatory of Japan (NAOJ) and Japan Aerospace Exploration Agency (JAXA) and then joined the NAOJ ALMA project in 2011. Made great contributions to performance verification of polarization observation with ALMA and received the 2017 NAOJ Director’s Award. From 2014 to 2017, played a leading role in the East Asian ALMA Data Analysis Team and supporting the production of various scientific results in collaboration with other team members. From 2017 October, serving as the interim manager of East-Asia ALMA Regional Center who coordinates the ALMA science operation activity and user support in East-Asia region.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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    NAOJ

     
  • richardmitnick 2:23 pm on September 21, 2018 Permalink | Reply
    Tags: ALMA, , , , , , , , The Rise of Astrotourism in Chile   

    From ESOblog: “The Rise of Astrotourism in Chile” 

    ESO 50 Large

    From ESOblog

    21 September 2018

    1
    Outreach@ESO

    For the ultimate stargazing experience, Chile is an unmissable destination. The skies above the Atacama Desert are clear for about 300 nights per year, so this high, dry and dark environment offers the perfect window to the Universe. Hundreds of thousands of tourists flock to Chile each year to take advantage of the incredible stargazing conditions, and to visit the scientific observatories — including ESO’s own — that use these skies as a natural astronomical laboratory. But one challenge now affecting Chile’s world-renowned dark skies is that of light pollution.

    The intense Sun beats down on the tourists’ cars as they climb the dusty desert road up Cerro Paranal. The 130-kilometre journey from the closest city of Antofagasta will be worth it because waiting at the top is ESO’s Paranal Observatory.

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

    The tourists have been eagerly awaiting their tour of this incredible site since they booked it a month ago. Every Saturday, two of ESO’s Chile-based observatories — Paranal and La Silla — open their doors for organised tours led by ESO’s education and Public Outreach Department on behalf of the ESO Representation Office.

    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres.

    Tourists come from far and wide to find out about the technology behind ESO’s world-class telescopes — how they are built and operated, and how astronomers use them to make groundbreaking discoveries. Each tour begins at the visitor centres, which are currently being upgraded with new content designed for the ESO Supernova Planetarium & Visitor Centre, before the guests are taken to see what they really came for: the telescopes.

    ESO Supernova Planetarium, Garching Germany

    Visits to Paranal are centred around ESO’s Very Large Telescope, the world’s most advanced optical instrument and the flagship facility of European optical astronomy. Visitors also see the control room where astronomers work, and the Paranal Residencia — the astronomers’ “home away from home” when they are observing in Chile.

    ESO Paranal Residencia exterior

    ESO Paranal Residencia inside near the swimming pool

    ESO Paranal Residencia dining room

    At La Silla, on the other hand, visitors spend time at the ESO 3.6-metre telescope and the New Technology Telescope before ending the day at the Swedish–ESO Submillimetre Telescope.


    ESO 3.6m telescope & HARPS at Cerro LaSilla, Chile, 600 km north of Santiago de Chile at an altitude of 2400 metres.


    ESO/NTT at Cerro La Silla, Chile, at an altitude of 2400 metres

    ESO Swedish Submillimetre Telescope at La Silla at 2400 meters

    Astronomy enthusiasts can also visit the Operational Support Facility for the impressive Atacama Large Millimeter/submillimeter Array (ALMA).

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

    The word “alma” means “soul” in Spanish, and there is definitely something spiritual about this extraordinary location. With its 66 antennas spreading across the desert, ALMA is a hugely popular observatory to visit — tourists book at least two months in advance for an eye-opening tour of the control room, laboratories, and antennas under maintenance.

    The tours at each of these three sites are led by a team of enthusiastic guides. Most are local students who love to share their passion for astronomy. Gonzalo Aravena, a guide at Paranal, thinks that “being a small part of the great astrotourism that exists in Chile today is something to be proud of”, and Jermy Barraza, a La Silla guide, believes that guiding visitors is “a great support to our country’s culture, and encourages awareness of the natural resources that should be protected”.

    2
    Tourists visiting ESO’s Paranal Observatory pose for a snapshot in front of two of the VLT Unit Telescopes.
    Credit: ESO

    With almost 10,000 visitors a year to Paranal and 4000 to La Silla, these ESO observatories are the most popular Chilean sites for astrotourists, especially those who want to visit scientific facilities. Francisco Rodríguez, ESO’s Press Officer in Chile, explains, “Astrotourists are increasingly enthusiastic about experiencing dark skies and impressive astronomical observatories, and ESO sees this reflected in the growing number of visitors that arrive each year — over the last four years we’ve seen the numbers double”. This value is especially impressive considering how difficult the observatories are to get to.

    ESO avoids organising tours and events at night, leaving astronomers undisturbed and able to focus on their scientific research. Usually daytime tours are the only way to visit an ESO observatory, however, the doors are often opened for special events; for example Mercury’s transit of the Sun in 2003 and the partial solar eclipse in 2010. Visitors come to ESO to see the impressive technology and to understand how a professional observatory works, which often leads them to make nighttime visits to other stargazing locations.

    “Chile is an amazing country for astrotourism,” says Rodríguez. “Visitors can combine day visits to the most impressive telescopes in the world, with nighttime views of the stars at tourism observatories across the country.”

    Observatories such as the Collowara Tourism Observatory are popping up specifically for amateur stargazers, and many hotels provide telescopes for their guests to enjoy the beautiful skies. Elqui Domos Hotel has gone even further — dome-shaped rooms feature removable ceilings that open onto the sky, and guests can sleep in observatory cabins with glass roofs. Various astronomical museums have also been opened, including the San Pedro Meteorite Museum, which also conducts stargazing tours.

    Recently, ESO actively collaborated with other governmental, academic, and scientific groups to support a governmental initiative called Astroturismo Chile. Its aim is to “transform Chile into an astrotouristic destination of excellence, to be admired and recognised throughout the world for its attractiveness, quality, variety and sustainability”. Fernando Comerón, the former ESO representative in Astroturismo Chile, elaborates that the strategy “aims to improve the quality and competitiveness of existing astrotourism activities, in addition to preparing the Chilean astrotourism roadmap for 2016–2025”.

    But Chile’s dark skies are facing a growing challenge. La Serena, the closest major city to La Silla Observatory, is expanding rapidly; the region’s population has swelled to over 700 000, growing by more than 200 000 people in the last 20 years. Although some of these people are astronomers and dark sky lovers, increased development can mean increased light pollution if not carefully handled.

    Light pollution is artificial light that shines where it is neither wanted or needed, arising from poorly-designed, incorrectly-directed light fixtures. Light that shines into the sky is scattered by air molecules, moisture and aerosols in the atmosphere, causing the night sky to light up. This phenomenon is known as skyglow. Solutions include power limits for public lighting; shielding street lamps, neon signs, and plasma screens; and stricter guidelines for sport and recreational facilities.

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    The arch of the Milky Way emerges from the Cerro Paranal on the left, and sinks into the bright lights of Antofagasta, the closest city to Paranal Observatory.
    Credit: Bruno Gilli/ ESO

    Dark skies are incredibly important to ESO Photo Ambassador, Petr Horálek, who reflects, “I remember a law called Norma Lumínica was signed in 1999 requiring that lighting in the three astronomically-sensitive regions of Chile be directed downwards instead of into the sky… Of course, there are no lamps along the roads close to the observatories”.

    The Norma Lumínica, which establishes protocols for lighting regulations in Chile, was recently updated in 2013 to adapt to new technologies.

    5
    The spectacularly clear skies over the ESO 3.6-metre telescope at La Silla show the Milky Way and its galactic bulge.
    Credit: Y. Beletsky (LCO)/ESO

    Chile is also working with international observatories to encourage UNESCO to add major astronomy sites such as Paranal Observatory to its World Heritage List.
    “By promoting the preservation of natural conditions, particularly the dark skies, astronomy contributes to the formation of an environmentally-aware society”, says Comerón.

    Over the next ten years, Chile plans to invest in many new observatories.

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    Giant Magellan Telescope, to be at the Carnegie Institution for Science’s Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high

    Currently, more than 50% of the world’s large telescopes are located there, and the Chilean government believe that by 2020 that value could rise to more than 70%. IndexMundi, a data portal that gathers statistics from around the world, suggests the annual number of visitors to Chile has more than quadrupled in the past 15 years In 2017, 6.45 million visitors arrived in Chile, many of whom were enticed by the incredible night skies, and the reports from the Astroturismo Chile initiative estimate that in the next decade, the number of astrotourists visiting Chile will triple.

    Chile has its work cut out to limit the impact of light pollution on its magnificent skies, but if successful the country will benefit greatly — as will the visitors who continue to flock there. As La Silla guide Yilin Kong says, “Astrotourism helps teach people about the importance of astronomy, and to encourage the next generations to participate in it”.

    See the full article here .


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    Stem Education Coalition

    Visit ESO in Social Media-

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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”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

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

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

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres.

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

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres.

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m.

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert.

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 11:09 am on September 7, 2018 Permalink | Reply
    Tags: ALMA, , , , , , Fierce Winds Quench Wildfire-like Starbirth in Far-flung Galaxy, Galaxy SPT2319-55, ,   

    From ALMA: “Fierce Winds Quench Wildfire-like Starbirth in Far-flung Galaxy” 

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

    From ALMA

    6 September, 2018

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

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

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

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

    1
    ALMA, aided by a gravitational lens, imaged the outflow, or “wind”, from a galaxy seen when the universe was only one billion years old. The ALMA image (circle call out) shows the hydroxyl (OH) molecules. These molecules trace the location of star-forming gas as it is fleeing the galaxy, driven by a supernova or black-hole powered “wind.” The background star field (Blanco Telescope Dark Energy Survey) shows the location of the galaxy. The circular, double-lobe shape of the distant galaxy is due to the distortion caused by cosmic magnifying effect of an intervening galaxy. Credit: ALMA (ESO/NAOJ/NRAO), Spilker; NRAO/AUI/NSF, S. Dagnello; AURA/NSF

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Astronomers using ALMA, with the aid of a gravitational lens, have detected the most-distant galactic “wind” of molecules ever observed, seen when the universe was only one billion years old. By tracing the outflow of hydroxyl (OH) molecules, which herald the presence of star-forming gas in galaxies, the researchers show how some galaxies in the early universe quenched an ongoing wildfire of starbirth.

    Some galaxies, like the Milky Way and Andromeda, have relatively slow and measured rates of starbirth, with about one new star igniting each year. Other galaxies, known as starburst galaxies, forge 100s or even 1000s of stars each year. This furious pace, however, cannot be maintained indefinitely.

    Milky Way NASA/JPL-Caltech /ESO R. Hurt

    Andromeda Galaxy Adam Evans

    To avoid burning out in a short-lived blaze of glory, some galaxies throttle back their runaway starbirth by ejecting, at least temporarily, vast stores of gas into their expansive halos, where the gas either escapes entirely or slowly rains back in on the galaxy, triggering future bursts of star formation.

    Up to now, however, astronomers have been unable to directly observe these powerful outflows in the very early universe, where such mechanisms are essential to prevent galaxies from growing too big, too fast.

    New observations with the Atacama Large Millimeter/submillimeter Array (ALMA), show, for the first time,a powerfulgalactic “wind” of molecules in a galaxy seen when the universe was only one billion years old. This result provides insights into how certain galaxies in the early universe were able to self-regulate their growth,so they could continue forming stars across cosmic time.

    “Galaxies are complicated, messy beasts, and we think outflows and winds are critical pieces to how they form and evolve, regulating their ability to grow,” said Justin Spilker, an astronomer at the University of Texas at Austin and lead author on a paper appearing in the journal Science.

    Astronomers have observed winds with the same size, speed, and mass in nearby starbursting galaxies, but the new ALMA observation is the most distant unambiguous outflow ever seen in the early universe.

    The galaxy, known as SPT2319-55, is more than 12 billion light-years away. It was discovered by the National Science Foundation’s South Pole Telescope.

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago, the University of California, Berkeley, Case Western Reserve University, Harvard/Smithsonian Astrophysical Observatory, the University of Colorado Boulder, McGill University, The University of Illinois at Urbana-Champaign, University of California, Davis, Ludwig Maximilian University of Munich, Argonne National Laboratory, and the National Institute for Standards and Technology. It is funded by the National Science Foundation.

    ALMA was able to observe this object at such tremendous distance with the aid of a gravitational lens provided by a different galaxy that sits almost exactlyalong the line of sight between Earth and SPT2319-55. Gravitational lensing – the bending of light due to gravity — magnifies the background galaxy to make it appear brighter, which allows the astronomers to observe it in more detail than they would otherwise be able to.

    Radio galaxies gravitationally lensed by a very large foreground galaxy cluster Hubble

    Astronomers use specialized computer programs to “unscramble” the effects of gravitational lensing to reconstruct an accurate image of the more-distant object.

    This lens-aided view revealed a powerful“wind” of star-forming gas exiting the galaxy at nearly 800 kilometers per second. Rather than a constant, gentle breeze, the wind is hurtling away in discrete clumps, removing the star-forming gas just as quickly as the galaxy can turn that gas into new stars.

    The outflow was detected by the millimeter-wavelength signature of a molecule called hydroxyl (OH), which appeared as an absorption line: essentially, the shadow of an OH fingerprint in the galaxy’s bright infrared light.

    As new, dust-enshrouded stars form, that dust heats up and glows brightly in infrared light. However, the galaxy is also launching a wind, and some of it is blowing in our direction. As the infrared light passes through the wind on its journey toward Earth, the OH molecules in the wind absorb some of the infrared light at a very particular wavelength that ALMA can observe.

    “That’s the absorption signature that we detected, and from that, we can also tell how fast the wind is moving and get a rough idea of how much material is contained in the outflow,” said Spilker. ALMA can detect this infrared light because it has been stretched to millimeter wavelengths on its journey to Earth by the ongoing expansion of the Universe.

    Molecular winds are an efficient way for galaxies to self-regulate their growth, the researchers note. These winds are likely triggered by either the combined effectof all the supernova explosions that go along with rapid, massive star formation or by a powerful release of energy as some of the gas in the galaxy falls down onto the supermassive black hole at its center.

    “So far, we have only observed one galaxy at such a remarkable cosmic distance, but we’d like to know if winds like these are also present in other galaxies to see just how common they are,” concluded Spilker. “If they occur in basically every galaxy, we know that molecular winds are both ubiquitous and also a prevalent way for galaxies to self-regulate their growth.”

    “This ALMA observation demonstrates how nature coupled with exquisite technology can give us insights into distant astronomical objects,” said Joe Pesce, NSF Program Director for NRAO/ALMA, “and the frequency range accessible to ALMA meant it was able to the detect the redshifted spectral feature from this important molecule.”

    3
    Artist impression of an outflow of molecular gas from an active star-forming galaxy. Credit: NRAO/AUI/NSF, D. Berry

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

    This research is presented in a paper titled Fast Molecular Outflow from a Dusty Star-Forming Galaxy in the Early Universe, by J.S. Spilker et al. in the journal Science and Science

    The research team was composed by J. S. Spilker [1,2,∗],M. Aravena [3], M. Béthermin [4], S. C. Chapman [5], C.-C. Chen [6], D. J. M. Cunningham [5,7], C. De Breuck [6], C. Dong [8], A. H. Gonzalez [8], C. C. Hayward [9,10], Y. D. Hezaveh [11], K. C. Litke [2], J. Ma [12], M. Malkan [13], D. P. Marrone [2], T. B. Miller [5,14], W. R. Morningstar [11], D. Narayanan [8], K. A. Phadke [15], J. Sreevani [15], A. A. Stark [10], J. D. Vieira [15], A. Weiß [16].

    [1] Department of Astronomy, University of Texas at Austin, 2515 Speedway Stop C1400, Austin, TX 78712, USA.

    [2] Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA.

    [3] Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago, Chile.

    [4] Aix-Marseille Univ., Centre National de la Recherche Scientifique, Laboratoire d’Astrophysique de Marseille, Marseille, France.

    [5] Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.

    [6] European Southern Observatory, Karl Schwarzschild Straße 2, 85748 Garching, Germany.

    [7] Department of Astronomy and Physics, Saint Mary’s University, Halifax, Nova Scotia, Canada.

    [8] Department of Astronomy, University of Florida, Bryant Space Sciences Center, Gainesville, FL 32611, USA.

    [9] Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Avenue, New York, NY 10010, USA.

    [10] Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.

    [11] Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA.

    [12] Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA

    [13] Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA.

    [14] Department of Astronomy, Yale University, 52 Hillhouse Avenue, New Haven, CT 06511, USA.

    [15] Department of Astronomy, University of Illinois, 1002 West Green St., Urbana, IL 61801, USA.

    [16] Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69 D-53121 Bonn, Germany.

    ∗Corresponding author. E-mail: spilkerj@gmail.com.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

    NRAO Small
    ESO 50 Large
    NAOJ

     
  • richardmitnick 2:13 pm on September 4, 2018 Permalink | Reply
    Tags: A precursor to a protoplanetary disk, ALMA, , , , , IRAS 15398-3359 is a Class 0 protostar   

    From Astrobiology Magazine: “Little star sheds light on young planets” 

    Astrobiology Magazine

    From Astrobiology Magazine

    Sep 4, 2018
    No writer credit

    1
    This is a false-color submillimeter-wavelength image of the IRAS 15398-3359 system 47 light years from Earth. Credit: Yuki Okoda, Graduate School of Science, The University of Tokyo.

    Early in 2017, Assistant Professor Yoko Oya gave graduate student Yuki Okoda some recent complex data on a nearby star with which she could begin her Ph.D. Little did she realize that what she would find could unlock not only the secrets of how planets form but possibly her career as a professional astronomer.

    The star in question (only known by its catalog number IRAS 15398-3359) is small, young and relatively cool for a star. It’s diminutive stature means the weak light it shines can’t even reach us through a cloud of gas and dust that surrounds it. But this doesn’t stop inquisitive minds from exploring the unknown.

    In 2013, Oya and her collaborators used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe the star in submillimeter wavelengths, as that kind of light can penetrate the dust cloud – for reference, red light is around 700 nanometers.

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

    A painstaking analysis revealed some interesting nebulous structures, despite the images they worked from being difficult to comprehend.

    “The greatest academic challenge I’ve faced was trying to make sense of grainy images. It’s extremely difficult to know exactly what you’re really looking at.” says Okoda. “But I felt compelled to explore the nature of the structures Dr. Oya had seen with ALMA, so I came up with a model to explain them.” The model she produced came as a surprise to Okoda and her colleagues, but it fit the data perfectly. It describes a dense disk of material that consists of gas and dust from the cloud that surrounds the star. This has never before been seen around such a young star.

    2
    IRAS 15398-3359 is a Class 0 protostar, invisible to human eyes, it must be viewed in longer wavelengths. Credit: Yuki Okoda, Graduate School of Science, The University of Tokyo

    The disk is a precursor to a protoplanetary disk, which is far denser still and eventually becomes a planetary system in orbit around a star.

    “We can’t say for sure this particular disk will coalesce into a new planetary system,” explains Oya. “The dust cloud may be pushed away by stellar winds or it might all fall into the star itself, feeding it in the process. What’s exciting is how quickly this might happen.”

    The star is small at around 0.7 percent the mass of our sun, based on observations of the mass of the surrounding cloud. It could grow to as large as 20 percent in just a few tens of thousands of years, a blink of the eye on the cosmic scale.

    “I hope our observations and models will enhance knowledge of how solar systems form,” says Okoda. “My research interests involve young protostellar objects, and the implication that protoplanetary disks could form earlier than expected really excites me.”

    Okoda began this project a year-and-a-half ago to hone her skills as an astronomer, but mirroring the young star she observed, the practice evolved quickly and became a full research project, which will hopefully earn her a Ph.D. from the University of Tokyo.

    The observations and resultant model were only possible thanks to advancements in radio astronomy with observatories such as ALMA. The team was lucky that the plane of the disk is level with our own solar system as this means the starlight ALMA sees passes through enough of the gas and dust to divulge important characteristics of it.

    “We were also lucky to be given time with ALMA to carry out our observations. Only about 20 percent of applications actually go ahead,” explains Oya. “With highly specialized astronomical instruments, there is much competition for time. My hope is our success will inspire a new generation of astronomers in Japan to reach for the stars.”

    The Co-evolution of Disks and Stars in Embedded Stages: The Case of the Very-low-mass Protostar IRAS 15398-3359Astrophysical Journal Letters

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 12:12 pm on September 1, 2018 Permalink | Reply
    Tags: ALMA, , , , Class 0 protostars, , , Precise Record of Baby-Stars’ Growth on Millimeter Wavelength,   

    From ALMA: “Precise Record of Baby-Stars’ Growth on Millimeter Wavelength” 

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

    From ALMA

    31 August, 2018

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

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

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

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

    1

    Babies grow up fast in the blink of an eye, and thus, their parents wish to record their growth without missing any moment; This is true not only for human babies but also for baby-stars, called protostars, although the recorders are not parents but astronomers in this case. Protostars’ age, or evolutionary stages, has been determined from observations at near and mid-infrared wavelengths. The youngest stage, called Class 0, is defined by non-detection at near and mid-infrared wavelengths, corresponding to <300,000 years old. This definition cannot differentiate younger from older Class 0 protostars. Furthermore, astronomers expect from studies on even older protostars that protostars grow up faster at earlier stages than at later stages, as human babies do, implying that they miss many precious moments of their growth.

    2
    The background image shows the Serpens Main star-forming cluster in the near infrared. The inset image shows the location of the two Class 0 protostars SMM4A and SMM4B in the entire group, in 1.3 mm wavelength. Credit: ESO/ALMA(ESO/NAOJ/NRAO)/Aso et al.

    As we all know, human “babies” (fetuses) in mothers’ wombs also grow at a fast rate – just as the star babies do. Using ultrasound scanning techniques, parents can hear the baby’s heart beating during the regular prenatal examinations; not only so, but they could also even detect how much the thigh bone grows, how much the head circumference is, or perhaps, getting some hints about “girl or boy?”! All of these are essential indicators informing us about how much progress our babies are making concerning growth.

    Similarly, to record the critical evolutionary stages of baby stars, rather than ultrasound scanners, astronomers would use millimeter/ sub-millimeter telescopes. To probe the fast growth of Class 0 protostars, an international team led by Dr. Yusuke Aso of Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan) has observed three Class 0 protostars using the Atacama Large Millimeter/submillimeter Array (ALMA) and has differentiated evolutionary stages of these protostars in multiple aspects. Thanks to ALMA’s strong capabilities, the team revealed four evolutionary indicators in details: (1) dusty disk growth on 100 astronomical-unit scales, (2) widening of outflow opening angles, (3) carbon monoxide (CO) desorption from icy grains due to temperature rising, and (4) weakening of accretion shock, all of which are consistent with theoretical predictions for young protostars.

    Their work demonstrates the importance of millimeter wavelength on probing young protostars’evolution. The work was also accomplished by ALMA’s high spatial resolution differentiating morphology on a small scale and its high sensitivity detecting the faint molecular line from the cold regions. The lead author Dr. Aso says: “From now on, the precious moments of young baby-stars’ fast growth will be recorded more precisely on millimeter wavelength.”

    Additional Information
    This research was presented in a paper The Distinct Evolutionary Nature of Two Class 0 Protostars in Serpens Main SMM4 by Aso et al. to appear in The Astrophysical Journal.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

    NRAO Small
    ESO 50 Large
    NAOJ

     
  • richardmitnick 11:31 am on August 18, 2018 Permalink | Reply
    Tags: A distant galaxy appears filled with dark matter, ALMA, , , , , ,   

    From Science News: “A galaxy 11.3 billion light-years away appears filled with dark matter” 

    From Science News

    August 17, 2018
    Lisa Grossman

    1
    LONG AGO AND FAR AWAY Using the telescopes of the Atacama Large Millimeter/submillimeter Array in Chile (shown), astronomers discovered the most distant yet galaxy that appears to be filled with dark matter.

    A distant galaxy appears filled with dark matter.

    The outermost stars in the Cosmic Seagull, a galaxy 11.3 billion light-years away, race too fast to be propelled by the gravity of the galaxy’s gas and stars alone. Instead, they move as if urged on by an invisible force, indicating the hidden presence of dark matter, astrophysicist Verónica Motta of the University of Valparaíso in Chile and her colleagues report August 8 [The Astrophysical Letters].

    “In our nearby universe, you see these halos of dark matter around galaxies like ours,” Motta says. “So we should expect that in the past, that halo was there, too.”

    Motta and her colleagues used radio telescopes at the Atacama Large Millimeter/submillimeter Array (ALMA) to measure the speed of gas across the Cosmic Seagull’s disk, from the center out to about 9,800 light-years. They found that the galaxy’s stars speed up as they get farther from the galaxy’s center.

    That’s a strange setup for most orbiting objects — when planets orbit a star, for instance, the most distant planets move slowest. But it can be explained if the galaxy’s far reaches are dominated by dark matter that speeds things along. Similar measurements of the Milky Way and neighboring galaxies provided one of the first signs that dark matter may exist, although physicists are still trying to detect the proposed particle directly (SN: 2/4/17, p. 15).

    Her team’s finding contrasts with a recent claim that such distant galaxies are oddly lacking in dark matter. That idea comes from a 2017 study by astronomer Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and his colleagues, who found more than 100 distant galaxies keep their slower stars at the edges and faster stars closer in — little to no dark matter required (SN: 4/15/17, p. 10).

    “In the astrophysical community, the [Genzel] result has been viewed with both excitement and skepticism,” says cosmologist Richard Ellis of University College London, who was not involved in either work. “It makes a lot of sense for others to examine galaxies at these [distances] in different ways.”

    Motta and her colleagues were able to probe dark matter in the most distant galaxy yet, thanks to a massive galactic train wreck called the Bullet Cluster that acted as a huge cosmic telescope.

    2
    M. Markevitch et al/CfA/CXC/NASA (X-ray); D. Clowe et al/U. Ariz./Magellan, ESO WFI, STScI/NASA (lensing map); D. Clowe et al/U. Ariz./Magellan, STScI/NASA (optical)

    The Cosmic Seagull lies behind the Bullet Cluster from Earth’s perspective, and the cluster’s mass distorts the Seagull’s light in a phenomenon called gravitational lensing.

    That distortion earned the disk-shaped galaxy its name — the first images reminded Motta’s team of the seagull logo of a popular music festival in Viña del Mar, Chile. But it also made the galaxy appear magnified by a factor of 50 — a new record.

    “Motta et al have exquisite data,” but their observations are limited, Ellis wrote in an e-mail. The team looked at only one galaxy, and that galaxy is much smaller and less massive than those that seem short on dark matter. Furthermore, the observations don’t cover the entire galactic disk, so the stars may be slower farther out than the team can see.

    Motta agrees that a distant slowdown is possible, although her observations cover the same portion of the galaxy’s disk as the study of galaxies that seem light on dark matter.

    “We are roughly at the place in which we should see the turning point” from fast to slow stars, if it exists, she says. “But we need to extend the study to get that.” Her team has been granted more time with ALMA next year to keep looking.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
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