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  • richardmitnick 9:53 am on August 15, 2016 Permalink | Reply
    Tags: , , , Radio Astronomy, realfast   

    From NRAO: “Real-time, Commensal Fast Transient Searches at the VLA” 

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    15 August 2016
    Casey Law (Berkeley), Joe Lazio (JPL), Geoff Bower (ASIAA), Sarah Burke-Spolaor (NRAO), Paul Demorest (NRAO), Bryan Butler (NRAO)

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    While the Expanded Very Large Array (VLA) project produced dramatic improvements in sensitivity and frequency coverage, its legacy may be defined by the introduction of powerful and flexible digital signal processing. The power and flexibility of the VLA correlator makes it uniquely capable of doing a broad range of science today and growing to do the science of tomorrow.

    One exciting pursuit for the VLA is the study of “fast radio bursts” (FRBs), a mysterious new class of millisecond radio transient. FRBs seem to come from far outside our galaxy, which would make them unusually luminous and novel probes of the intergalactic medium. As the most sensitive centimeter-wavelength radio interferometer on earth, the VLA will revolutionize this field with its ability to precisely localize sources to identify multi-wavelength counterparts (e.g., a host galaxy). Previously, our group has demonstrated that potential with the introduction of “fast imaging”, a new concept for using the VLA as a high speed camera. Now, we are expanding on that concept with the construction of realfast, a 24 / 7 fast transient survey system at the VLA.

    The core of realfast is a 32-node, Graphics Processing Unit-accelerated compute cluster that will perform real-time transient searches on millisecond timescales as data are received at the VLA, before averaging the data for archive storage. Real-time processing will allow us to rapidly identify transients and trigger recording of data for those brief moments when a transient candidate is detected. Triggered data recording reduces the data flow by orders of magnitude and makes it feasible to observe continuously. We will integrate this system with a duplicate high-speed data stream to turn each VLA observation into a fast transient survey, ultimately encompassing thousands of hours per year.

    Realfast will be supported by a three-year grant from the National Science Foundation Advanced Technologies and Instrumentation program and developed in close collaboration with NRAO staff. Transient alerts and associated data products will be made public. This will make the VLA into a transient survey machine and help connect the public to our rapidly changing understanding of the rapidly changing sky.

    For additional information, visit the realfast website.

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    The challenge to using the VLA for millisecond imaging is that it produces roughly 1 TB of data per hour and requires forming many thousands of images per second. This data rate is so large that it cannot be transferred via the internet for data analysis. The computing requirements are so severe that no single computer can manage the search. The question is: how can we manage a TB/hour data stream to find a millisecond transient in hudreds of hours of data?
    Our answer is realfast, a system for real-time fast transient searches at the VLA. Real-time processing is critical, as it allows triggered data recording and opens access to “commensal” observing in conjunction with other VLA observations. realfast is supported by the NSF ATI program starting in late 2016.

    See the full article here .

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

    ALMA Array

    NRAO ALMA

    NRAO/GBT radio telescope
    NRAO GBT

    NRAO VLA
    NRAO VLA

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

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

     
  • richardmitnick 9:38 am on August 15, 2016 Permalink | Reply
    Tags: , ALMA Achieved Highest Polarimetric Sensitivity, , , , Radio Astronomy   

    From ALMA: “ALMA Achieved Highest Polarimetric Sensitivity” 

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

    Monday, 18 July 2016 [Just found this at ALMA’s website. Never saw it in social media.]
    Nicolás Lira T.
    Education and Public Outreach Coordinator
    Joint ALMA Observatory
    Santiago, Chile
    Tel: +56 2 24 67 65 19
    Cell: +56 9 94 45 77 26
    Email: nicolas.lira@alma.cl

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

    1
    3C 286 observed with ALMA. Contours shows the intensity of radio waves and purple bars shows the polarization direction. The central part of the quasar is located in the center of the image, and a part of the jet ejected by the quasar is seen on the right. Credit: ALMA (ESO/NAOJ/NRAO), Nagai et al.

    Researchers have confirmed ALMA’s unprecedented capability for polarimetry in millimeter/submillimeter wavebands. Polarimetry is an important method to investigate magnetic fields in the Universe and astronomers are eager to use ALMA for unveiling magnetic mysteries, such as the launching mechanism of high energy jets from supermassive black holes.

    The magnetic field is ubiquitous and plays considerable roles in the Universe. We can find the directions by using a compass thanks to Earth’s magnetic field. Sunspots and solar flares are driven by magnetic fields in the Sun. Magnetic fields are also important in various occasions including formation of stars and planets, and exotic events around black holes. In spite of its significance, measurement of magnetic fields is difficult. Polarimetry is one of the handful methods to investigate magnetic fields in the Universe.

    ALMA is designed to perform sensitive polarimetry observations. To verify its capability, astronomers observe well-known objects and compare the results with those of existing telescopes. ALMA started science observations in 2011, but in parallel, science verification activities for advanced observation methods have been carried out.

    ALMA observed the bright source 3C 286 for the verifications of polarimetry observations. The source, located 7.3 billion light years away from us, is a quasar, emitting very strong radio waves. Many researchers assume that a supermassive black hole is located in the center of a quasar and intense magnetic fields are responsible for ejecting powerful jets. ALMA pointed to the root of the jet from 3C 286 to measure the intensity and the direction of the polarized wave. The result reveal details not seen before and clearly show that the magnetic field is stronger and more ordered towards the inner region of the jet that emerges from the quasar. This helps researchers to understand the magnetic field structure in the very heart of the quasar, furnishing vital clues about the physical processes that give rise to the radio emission.

    “This observation has certainly verified the high capability of the polarimetry observation with ALMA,” said Hiroshi Nagai at the National Astronomical Observatory of Japan and the leader of the verification team. “This is an important milestone for the ALMA project.”

    In general, the polarized component is as weak as a few percent of the total radio flux from an object. High sensitivity is essential for the precise polarimetry, and ALMA is suitable for it. The science verification activity includes the establishment of the proper calibration and many test observations have been performed to ensure the high precision. Such behind-the-scenes efforts provide a firm platform for advanced observations with ALMA.

    Additional information

    These observation results were published by Nagai et al. as “ALMA Science Verification Data: Millimeter Continuum Polarimetry of the Bright Radio Quasar 3C 286” in the Astrophysical Journal issued on 20 June 2016.

    The science verification activities for polarimetry is introduced in an article Polarization observations with ALMA in the serial column “¡Bienvenido a ALMA!”.

    The first scientific results containing ALMA full polarization data were published by the Astrophysical Journal Letters on June 30, 2016, as Interferometric Mapping Of Magnetic Fields: The Alma View Of The Massive Star-Forming Clump W43-MM1 by Cortés et al.

    See the full article here .

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

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

    NRAO Small

    ESO 50

    NAOJ

     
  • richardmitnick 8:56 am on August 11, 2016 Permalink | Reply
    Tags: , , , Radio Astronomy,   

    From Many Worlds: “SETI Reconceived and Broadened” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2016-08-11
    Marc Kaufman
    marc.kaufman@manyworlds.space

    1
    SETI’s Allen Telescope Array situated at the Hat Creek Radio Observatory, 290 miles (470 km) northeast of San Francisco, California, USA, the focus of the organization’s effort to collect signals from distant planets, and especially signals that just might have been created by intelligent beings. (SETI)

    For decades, the Search for Extraterrestrial Intelligence (SETI) and its SETI Institute home base have been synonymous with the search for intelligent, technologically advanced life beyond Earth.

    SETI Institute

    The pathway to some day finding that potentially sophisticated life has been radio astronomy and the parsing of any seemingly unnatural signals arriving from faraway star system — signals that just might be the product of intelligent extraterrestrial life.

    It has been a lonely five decade search by now, with some tantalizing anomalies to decipher but no “eurekas.” After Congress defunded SETI in the early 1990s — a Nevada senator led the charge against spending taxpayer money to look for “little green men” — the program has also been chronically in need of, and looking for, private supporters and benefactors.

    But to those who know it better, the SETI Institute in Mountain View, California has long been more than that well-known listening program. The Institute’s Carl Sagan Center for Research is home to scores of respected space, communication, and astrobiology scientists, and most have little or nothing to do with the specific message-analyzing arm of the organization.

    And now, the new head of the Carl Sagan Center has proposed an ambitious effort to further re-define and re-position SETI and the Institute. In a recent paper in the Astrobiology Journal, Nathalie Cabrol has proposed a much broader approach to the search for extraterrestrial intelligence, incorporating disciplines including psychology, social sciences, communication theory and even neuroscience to the traditional astronomical approach.

    “To find ET, we must open our minds beyond a deeply-rooted, Earth-centric perspective, expand our research methods and deploy new tools,” she wrote. “Never before has so much data been available in so many scientific disciplines to help us grasp the role of probabilistic events in the development of extraterrestrial intelligence.

    “These data tell us that each world is a unique planetary experiment. Advanced intelligent life is likely plentiful in the universe, but may be very different from us, based on what we now know of the coevolution of life and environment.”

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    With billions upon billions of galaxies, stars and exoplanets out there, some wonder if the absence of a SETI signal means none are populated by intelligent being. Others say the search remains in its infancy, and needs new approaches. The galaxy as viewed by the Hubble Space Telescope. (NASA/STScI)

    She also wants to approach SETI with the highly interdisciplinary manner found in the burgeoning field of astrobiology — the search for signs of any kind of life beyond Earth. And in a nod to NASA’s Astrobiology Institute, which has funded most of her work, Cabrol went on to call for the establishment of a SETI Virtual Institute with participation from the global scientific community.

    I had the opportunity recently to speak with Cabrol, who is a French-American astrobiologist with many years of research experience working with the NASA Mars rover program and with extremophile research as a senior SETI scientist. She sees the SETI search for technologically advanced life as very much connected with the broader goals of the astrobiology field, which are focused generally on signs of potential microbial extraterrestrial life. Yes, she said, SETI has thus far a distinctive and largely separate role in the overall astrobiology effort, but now she wants that role to be significantly updated and broadened.

    “The time is right for a new chapter for us,” she said. “The origins of SETI were visionary — using the hot technology of the day {radio astronomy} to listen for signals. But we don’t exactly know what to look and listen for. We don’t know the ways that ET might interact with its own environment, and that’s a drawback when looking for potential communications we might detect.”

    Cabrol foresees future SETI Institute research into neural systems and how they interact with the environment (“bioneural computing,”) much more on the theory and mechanisms of communication, as well as on big data analysis and machine learning. And, of course, into how potential biosignatures might be detected on distant planets.

    The ultimate goal, however, remains the same: detecting intelligent life (if it’s out there.)

    3
    Nathalie Cabrol, director of SETI’s Carl Sagan Center, wants to expand and update SETI’s approach to searching for intelligent life beyond our solar system. (NASA)

    But with so much progress in the sciences that could help improve the chances of finding evolved extraterrestrial life, she said, it’s time for SETI to focus on them as a way to expand the SETI vision and its strategies.

    “The purpose is to expand the vision and strategies for SETI research and to break through the constraints imposed by imagining ET to be similar to ourselves,” she wrote. The new approach will “probe the alien landscapes and mindscapes, and generally further understanding of life in the universe.”

    The Institute will soon put out a call for white papers on how to expand the SETI search beyond radio astronomy, with an emphasis on “life as we don’t know it.” After getting those white papers — hopefully from scientists ranging from astronomers to evolutionary biologists — the Sagan Center plans a workshop to create a roadmap.

    Cabrol was emphatic in saying that the SETI search is not turning away from the original vision of its founders — especially astrophysicists Frank Drake, Jill Tarter and Carl Sagan — who were looking for a way to quantify the likelihood of intelligent and technologically-proficient life on distant planets. Rather, it’s an effort to return to and update the initial SETI formulation, especially as expressed in the famed Drake Equation.

    4
    The Drake Equation, as first presented in 1961 to a gathering of scientists at the National Radio Astronomy Observatory in Green Bank, W. Va.

    “What Frank proposed was actually a roadmap itself,” Cabrol said. “The equation takes into account how suitable stars are formed, how many planets they might have, how many might be Earth-like planets, and how many are habitable or inhabited.”

    Drake’s equation was formulated for the pioneering Green Bank Conference more than 50 years ago, when basically none of the components of his formula had a number or range that could be associated with it. That has changed for many of those components, but the answer to the original question — Are We Alone? — remains little closer to being answered.

    “I’ve talked a great deal with my colleagues about what type of life can be out there,” she said. “How different from Earth can it be?”

    “Now we’re looking for habitable environments with life as we know it. But it’s time to add life as we don”t know it, too. And that can help augment our targeting, help pinpoint better what we’re looking for.”

    “We think one of the key issues is how ET communicates with its environment, and the great advances in neuroscience can help inform what we do. The same with evolutionary biology. Given an environment with life, we want to know, what kind of evolution might be anticipated.”

    5
    A diagram of the proposed SETI “connectivity network” between disciplines showing the bridges and research avenues that link together space, planetary, and life sciences, geosciences, astrobiology, and cognitive and mathematical sciences. Cabrol describes it as an expanded version of the Drake equation. (Astrobiology Journal/SETI Institute.)

    These are, of course, very long-term goals. No extraterrestrial life has been detected, and researchers are just now beginning to debate and formulate what might constitute a biosignature on a faraway exoplanet or, what has more recently been coined, a “bio-hint.”

    In her paper, Cabrol is also frank about the entirely practical, real-world reasons what SETI needs to change.

    “Decades of perspective on both astrobiology and the Search for Extraterrestrial Intelligence (SETI) show how the former has blossomed into a dynamic and self-regenerating field that continues to create new research areas with time, whereas funding struggles have left the latter starved of young researchers and in search of both a long-term vision and a development program.

    “A more foundational reason may be that, from the outset, SETI is an all-or-nothing venture where finding a signal would be a world-changing discovery, while astrobiology is associated with related fields of inquiry in which incremental progress is always being made.”

    Whatever changes arrive, SETI will continue with its trademark efforts such as SETI@home — through which enthusiasts can help monitor and read incoming data on their computers — and the radio telescope observing itself. [This article is incorrect in stating that seti@home is a SETI Institute effort. seti@home is a BOIONC project at Space Science Lab, UC Berkeley seti@home receives data from the Arecibo Radio Telescope in Puerto Rico.] The Allen Telescope Array in Northern California came began its work in 2007 with 42 interconnected small telescopes. The SETI Institute had hoped to build the array up to 350 telescopes, but the funding has not been forthcoming.

    Cabrol is clearly a scientific adventurer and risk taker. During her extremophile research in Chile, she went scuba diving and free diving — that is, diving without scuba equipment — in the Licancabur Lake, some 20,000 feet above sea level. It is believed to be an unofficial altitude record high-altitude for both kinds of diving.

    With this kind of view of life, she is a logical candidate to bring substantial change to SETI. The new primary questions for SETI and the institute to probe are: How abundant is intelligent life in the universe? How does it communicate? How can we detect intelligent life?

    As she concluded in her Astrobiology Journal article:

    ‘Ultimately, SETI’s vision should no longer be constrained by whether ET has technology, resembles us, or thinks like us. The approach presented here will make these attributes less relevant, which will vastly expand the potential sampling pool and search methods, ultimately increasing the odds of detection.

    “Advanced, intelligent life beyond Earth is most likely plentiful, but we have not yet opened ourselves to the full potential of its diversity.”

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 1:32 pm on August 5, 2016 Permalink | Reply
    Tags: , , , MWA - Murchison Widefield Array, Radio Astronomy   

    From CfA: “The Murchison Widefield Array” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    July 8, 2016
    No writer credit

    1
    MWA

    Counting up the number of objects of different kinds can help distinguish between models of how they form and evolve. Astronomers have traditionally used number counts of radio sources to learn about the nature of extragalactic source populations. The vast bulk of their radio continuum emission comes from a central active galactic nucleus and/or from ongoing star formation. The bright sources are relatively easy to identify, but they are rare — more common are the moderate and low-power extragalactic radio sources. Extragalactic sources are located across a large range of cosmic distances, and because distant sources are fainter, they contribute particularly to the dim source counts. One of the major challenges for astronomers, therefore, is to get accurate statistics on sources that are intrinsically faint without counting in their company too many sources that are bright but just farther away. Number count statistics can do a good job of sorting out these possibilities.

    The Murchison Widefield Array Square (MWA) is a low-frequency radio telescope, operating at meter-size wavelengths, and located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia. It is a powerful survey instrument, an array of one hundred and twenty eight small telescopes, having both good sensitivity and a very wide field of view, and thus being an excellent tool for radio number counts. CfA astronomer Lincoln Greenhill was part of a large team that used the MWA to study faint source counts as part of a longer-term program to explore the universe as far back as the epoch of the first stars, only a few hundred million years after the big bang. In these first MWA observations, the team tested concepts and identified potential issues, including effects of the ionosphere and source confusion. Future studies will be undertaken with the very much larger Square Kilometer Array facility now under construction.

    SKA Square Kilometer Array

    Reference(s):

    The 154 MHz Radio Sky Observed by the Murchison Widefield Array: Noise, Confusion, and First Source Count Analyses, Franzen, T. M. O.; Jackson, C. A.; Offringa, A. R.; Ekers, R. D.; Wayth, R. B.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Deshpande, A. A.; Gaensler, B. M.; Greenhill, L. J.; Hazelton, B. J.; Johnston-Hollitt, M.; Kaplan, D. L.; Lonsdale, C. J.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Oberoi, D.; Ord, S. M.; Prabu, T.; Seymour, N.; Shankar, N. Udaya; Srivani, K. S.; Subrahmanyan, R.; Tingay, S. J.; Trott, C. M.; Webster, R. L.; Williams, A.; Williams, C. L., MNRAS 459, 3314, 2016.

    See the full article here .

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    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 1:11 pm on July 29, 2016 Permalink | Reply
    Tags: , , , , NGC 4945, Radio Astronomy, U Manchester   

    From U Manchester: “Astronomers Uncover Hidden Stellar Birthplace” 

    U Manchester bloc

    University of Manchester

    26 July, 2016
    Joe Paxton

    1
    No image caption. No image credit.

    A team of astronomers from the University of Manchester, the Max Planck Institute for Radio Astronomy and the University of Bonn have uncovered a hidden stellar birthplace in a nearby spiral galaxy, using a telescope in Chile. The results show that the speed of star formation in the centre of the galaxy – and other galaxies like it – may be much higher than previously thought.

    The team penetrated the thick dust around the centre of galaxy NGC 4945 using the Atacama Large Millimeter Array (ALMA), a single telescope made up of 66 high precision antennas located 5000 metres above sea level in northern Chile.

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

    Astronomers typically look for ultraviolet light or infrared emissions from the brightest, hottest, and bluest stars. The places where stars form are often surrounded by interstellar dust that absorbs the ultraviolet and visible light from the hot blue stars, making it difficult to see where stars are forming. However, the interstellar dust gets warmer when it absorbs light and produces infrared radiation.

    NGC 4945 is unusual because the interstellar dust is so dense that it even absorbs the infrared light that it produces, meaning that astronomers find it hard to know what is happening in the centre of the galaxy. However, ALMA is able to see through even the thickest interstellar dust.

    “When we looked at the galaxy with ALMA, its centre was ten times brighter than we would have anticipated based on the mid-infrared image. It was so bright that I asked one of my collaborators to check my calculations just to make sure that I hadn’t made an error.”
    Dr. George J. Bendo

    “While it looks very dusty and very bright in the infrared compared to the Milky Way or other nearby spiral galaxies, it is very similar to other infrared-bright starburst galaxies that are more common in the more distant universe. If other astronomers are trying to look at star formation using infrared light, they might be missing a lot of what’s happening if the star forming regions are as obscured as in NGC 4945.”

    Fellow collaborator Professor Gary Fuller, also from the University of Manchester, added: “These results demonstrate the remarkable power of ALMA to study star formation which would otherwise be hidden.”

    See the full article here .

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    U Manchester campus

    The University of Manchester (UoM) is a public research university in the city of Manchester, England, formed in 2004 by the merger of the University of Manchester Institute of Science and Technology (renamed in 1966, est. 1956 as Manchester College of Science and Technology) which had its ultimate origins in the Mechanics’ Institute established in the city in 1824 and the Victoria University of Manchester founded by charter in 1904 after the dissolution of the federal Victoria University (which also had members in Leeds and Liverpool), but originating in Owens College, founded in Manchester in 1851. The University of Manchester is regarded as a red brick university, and was a product of the civic university movement of the late 19th century. It formed a constituent part of the federal Victoria University between 1880, when it received its royal charter, and 1903–1904, when it was dissolved.

    The University of Manchester is ranked 33rd in the world by QS World University Rankings 2015-16. In the 2015 Academic Ranking of World Universities, Manchester is ranked 41st in the world and 5th in the UK. In an employability ranking published by Emerging in 2015, where CEOs and chairmen were asked to select the top universities which they recruited from, Manchester placed 24th in the world and 5th nationally. The Global Employability University Ranking conducted by THE places Manchester at 27th world-wide and 10th in Europe, ahead of academic powerhouses such as Cornell, UPenn and LSE. It is ranked joint 56th in the world and 18th in Europe in the 2015-16 Times Higher Education World University Rankings. In the 2014 Research Excellence Framework, Manchester came fifth in terms of research power and seventeenth for grade point average quality when including specialist institutions. More students try to gain entry to the University of Manchester than to any other university in the country, with more than 55,000 applications for undergraduate courses in 2014 resulting in 6.5 applicants for every place available. According to the 2015 High Fliers Report, Manchester is the most targeted university by the largest number of leading graduate employers in the UK.

    The university owns and operates major cultural assets such as the Manchester Museum, Whitworth Art Gallery, John Rylands Library and Jodrell Bank Observatory which includes the Grade I listed Lovell Telescope.

     
  • richardmitnick 6:39 am on July 23, 2016 Permalink | Reply
    Tags: , Radio Astronomy, , Statement from the Board of Directors of SKA Organisation on the outcome of the UK’s EU referendum   

    From SKA: “Statement from the Board of Directors of SKA Organisation on the outcome of the UK’s EU referendum” 

    SKA Square Kilometer Array

    SKA

    The Board of Directors of the Square Kilometre Array (SKA) Organisation recently met at the SKA Headquarters at Jodrell Bank near Manchester in the UK for its 21st Board Meeting. This is the first time the Board has met since the result of the UK’s EU referendum held a few weeks ago and the consequent decision to leave the EU.

    Dr Adam Baker from the Science and Research Directorate of the UK Department for Business, Energy and Industrial Strategy (BEIS) reaffirmed the strong commitment of the country to the SKA project stating that “with respect to the Square Kilometre Array itself, the UK’s position has not changed. We are still deeply committed to the SKA and its success. The Minister for Universities and Science, Jo Johnson re-iterated the UK’s support for world class research and innovation at a speech to the Wellcome Trust on 30th June. This included specific reference to the SKA.”

    All SKA members’ representatives in the Board took note of the positive statement from the UK, keeping the project on the right track ahead of the construction in 2018 in particular the pursuing of international negotiations to establish the SKA as an Inter-Governmental Organisation or IGO –similar to CERN or ITER.

    All members of the Board, the Director-General of SKA Organisation and the Chair of the Board also took this opportunity to express their pride in the international nature of the SKA project and emphasised the essential contribution of the highly qualified personnel from over 14 different nationalities working at the SKA Headquarters in the UK as well as around the world to deliver the project.

    “The recruitment of talent from around the world is what makes a project such as SKA possible and all members of the Board remain fully committed to ensuring the SKA project can attract and recruit the best and most qualified staff regardless of their origin,” concluded Giovanni Bignami, Chair of the SKA Board.

    See the full article here .

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    About SKA

    The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

    Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.

     
  • richardmitnick 8:26 am on July 17, 2016 Permalink | Reply
    Tags: , First Light, Radio Astronomy,   

    From SKA: “MeerKAT joins the ranks of the world’s great scientific instruments through its First Light image” 

    SKA Square Kilometer Array

    SKA

    16 July 2016
    Lorenzo Raynard, SKA SA Communication Manager
    lorenzo@ska.ac.za
    (+27) 71 454 0658

    1
    IMAGE 1: MeerKAT First Light image. Each white dot represents the intensity of radio waves recorded with 16 dishes of the MeerKAT telescope in the Karoo (when completed, MeerKAT will consist of 64 dishes and associated systems). More than 1300 individual objects – galaxies in the distant universe – are seen in this image.

    The MeerKAT First Light image of the sky, released today by Minister of Science and Technology, Naledi Pandor, shows unambiguously that MeerKAT is already the best radio telescope of its kind in the Southern Hemisphere. Array Release 1 (AR1) being celebrated today provides 16 of an eventual 64 dishes integrated into a working telescope array. It is the first significant scientific milestone achieved by MeerKAT, the radio telescope under construction in the Karoo that will eventually be integrated into the Square Kilometre Array (SKA).

    SKA Meerkat telescope, South African design
    SKA Meerkat telescope, South African design

    3
    When fully up and running in the 2020s, the SKA will comprise a forest of 3,000 dishes spread over an area of a square kilometre (0.4 square miles) across remote terrain around several countries. phys.org

    In a small patch of sky covering less than 0.01 percent of the entire celestial sphere, the MeerKAT First Light image shows more than 1300 galaxies in the distant Universe, compared to 70 known in this location prior to MeerKAT. “Based on the results being shown today, we are confident that after all 64 dishes are in place, MeerKAT will be the world’s leading telescope of its kind until the advent of SKA,” according to Professor Justin Jonas, SKA South Africa Chief Technologist.

    MeerKAT will consist of 64 receptors, each comprising a 13.5-metre diametre dish antenna, cryogenic coolers, receivers, digitiser, and other electronics. The commissioning of MeerKAT is done in phases to allow for verification of the system, early resolution of any technical issues, and initial science exploitation. Early science can be done with parts of the array as they are commissioned, even as construction continues. AR1 consists of 16 receptors, AR2 of 32 and AR3 of 64, expected to be in place by late 2017.

    Dr Rob Adam, Project Director of SKA South Africa, says: “The launch of MeerKAT AR1 and its first results is a significant milestone for South Africa. Through MeerKAT, South Africa is playing a key role in the design and development of technology for the SKA. The South African team of more than 200 young scientists, engineers and technicians, in collaboration with industry, local and foreign universities and institutions, has developed the technologies and systems for MeerKAT. These include cutting edge telescope antennas and receivers, signal processing, timing, telescope management, computing and data storage systems, and algorithms for data processing.”

    2
    IMAGE 2: Montage of MeerKAT First Light radio image and four zoomed-in insets. The two panels to the right show distant galaxies with massive black holes at their centers. At lower left is a galaxy approximately 200 million light years away, where hydrogen gas is being used up to form stars in large numbers.

    3
    IMAGE 3: View showing 10% of the full MeerKAT First Light radio image. More than 200 astronomical radio sources (white dots) are visible in this image, where prior to MeerKAT only five were known (indicated by violet circles). This image spans about the area of the Earth’s moon.

    In May 2016, more than 150 researchers and students, two-thirds from South Africa, met in Stellenbosch to discuss and update the MeerKAT science programme. This will consist of already approved “large survey projects”, plus “open time” available for new projects. An engineering test image, produced with only 4 dishes, was made available just before that meeting.

    “The scientists gathered at the May meeting were impressed to see what 4 MeerKAT dishes could do,” says Dr Fernando Camilo, SKA South Africa Chief Scientist. “They will be astonished at today’s exceptionally beautiful images, which demonstrate that MeerKAT has joined the big leagues of world radio astronomy”.

    Pandor today released the MeerKAT First Light image from the telescope site in the Northern Cape. She was accompanied by Ministers and Deputy Ministers from the Presidential Infrastructure Coordination Committee (PICC), as well as other senior officials.

    Minister Pandor says: “South Africa has already demonstrated its excellent science and engineering skills by designing and building MeerKAT. This telescope, which is predominantly a locally designed and built instrument, shows the world that South Africa can compete in international research, engineering, technology and science. Government is proud of our scientists and engineers for pioneering a radio telescope that will lead to groundbreaking research.”

    MeerKAT is a precursor to the Square Kilometre Array (SKA) and follows the KAT-7 telescope which was an engineering test-bed for MeerKAT. MeerKAT is funded by the South African Government and is a South African designed telescope with 75% of its value sourced locally. MeerKAT will be an integral part of SKA Phase 1. An important aspect of the SKA site decision in 2012 was that MeerKAT would be part of the sensitive SKA Phase 1 array, which will be the most sensitive radio telescope in the world. Upon completion at the end of 2017, MeerKAT will consist of 64 dishes and associated instrumentation. SKA1 MID will include an additional 133 dishes, bringing the total number for SKA1 MID to 197.

    See the full article here .

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    SKA Meerkat telescope
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    About SKA

    The Square Kilometre Array will be the world’s largest and most sensitive radio telescope. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity, and 10 000 times the survey speed, of the best current-day telescopes. The SKA will be built in Southern Africa and in Australia. Thousands of receptors will extend to distances of 3 000 km from the central regions. The SKA will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of the Universe, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. Construction of phase one of the SKA is scheduled to start in 2016. The SKA Organisation, with its headquarters at Jodrell Bank Observatory, near Manchester, UK, was established in December 2011 as a not-for-profit company in order to formalise relationships between the international partners and centralise the leadership of the project.

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, led by SKA Organisation. The SKA will conduct transformational science to improve our understanding of the Universe and the laws of fundamental physics, monitoring the sky in unprecedented detail and mapping it hundreds of times faster than any current facility.

    Already supported by 10 member countries – Australia, Canada, China, India, Italy, New Zealand, South Africa, Sweden, The Netherlands and the United Kingdom – SKA Organisation has brought together some of the world’s finest scientists, engineers and policy makers and more than 100 companies and research institutions across 20 countries in the design and development of the telescope. Construction of the SKA is set to start in 2018, with early science observations in 2020.

     
  • richardmitnick 2:12 pm on July 13, 2016 Permalink | Reply
    Tags: , ALMA Observes First Protoplanetary Water Snow Line Thanks to Stellar Outburst, , , , Radio Astronomy   

    From ALMA: “ALMA Observes First Protoplanetary Water Snow Line Thanks to Stellar Outburst” 

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

    13 July 2016
    Lucas Cieza
    Universidad Diego Portales
    Santiago, Chile
    Tel: +56 22 676 8154
    Cell: +56 95 000 6541
    Email: lucas.cieza@mail.udp.cl

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

    Richard Hook
    Public Information Officer, ESO

    Garching bei München, Germany

    Tel: +49 89 3200 6655

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

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

    Masaaki Hiramatsu

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

    Tel: +81 422 34 3630

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

    1
    Artist impression of the water snowline around the young star V883 Orionis, as detected with ALMA. Credit: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO).

    New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) have produced the first image of a water snow line within a protoplanetary disk. This line marks where the temperature in the disk surrounding a young star drops sufficiently low for snow to form. A dramatic increase in the brightness of the young star V883 Orionis flash heated the inner portion of the disk, pushing the water snow line out to a far greater distance than is normal for a protostar, and making it possible to observe it for the first time. The results will be published in the journal Nature on July 14, 2016.

    2
    Image of the planet-forming disc around the young star V883 Orionis was obtained by ALMA in long-baseline mode. This star is currently in outburst, which has pushed the water snow line further from the star and allowed it to be detected for the first time. The dark ring midway through the disc is the water snowline, the point from the star where the temperature and pressure dip low enough for water ice to form. Credit: ALMA (ESO/NAOJ/NRAO)/L. Cieza.

    Young stars are often surrounded by dense, rotating disks of gas and dust, known as protoplanetary disks, from which planets are born. Snow lines are the regions in those disks where the temperature reaches the sublimation point for most of the volatile molecules. In the inner disk regions, inside water snow lines, water is vaporized, while outside these lines, in the outer disk, water is found frozen in the form of snow. These lines are so important that they define the basic architecture of planetary systems like our own [1] and are usually located for a typical solar-type star at around 3 au from the star [2].

    However, the recent ALMA observations, to be published in Nature, show that the water snow line in V883 Orionis is currently at more than 40 au of the central star (corresponding to Neptune’s orbit in our system), greatly facilitating its detection [3]. This star is only thirty percent more massive than the Sun, but its luminosity is 400 times brighter as it’s currently experiencing what is known as a FU Ori outburst, a sudden increase in temperature and luminosity due to large amounts of material being transferred from the disk to the star [4]. This explains the displaced location of its water snow line: the disk has been flash-heated by the stellar outburst.

    Lead author Lucas Cieza explains: “The ALMA observations came as a surprise to us. Our observations were designed to look for disk fragmentation leading to planet formation. We saw none of that; instead, we found what looks like a ring at 40 au. This illustrates well the transformational power of ALMA, which delivers exciting results even if they are not the ones we were looking for.”

    The discovery that these outbursts may blast the water snow line to about 10 times its typical radius is very significant for the development of good planetary formation models. Such outbursts are believed to be a stage in the evolution of most planetary systems, so this may be the first observation of a common occurrence. In that case, this observation from ALMA could contribute significantly to a better understanding of how planets form and evolve throughout the Universe.

    3
    This illustration shows how the outburst of the young star V883 Orionis has displaced the water snowline much further out from the star, and rendered it detectable with ALMA. Credit: ALMA (ESO/NAOJ/NRAO)/L. Cieza.

    4
    This image of the planet-forming disc around the young star V883 Orionis was obtained by ALMA in long-baseline mode. This star is currently in outburst, which has pushed the water snow line further from the star and allowed it to be detected for the first time. The dark ring midway through the disc is the water snowline, the point from the star where the temperature and pressure dip low enough for water ice to form. Credit: ALMA (ESO/NAOJ/NRAO)/L. Cieza.

    Notes

    [1] In the solar nebula – which gave birth to our Solar System – this line was between the orbits of Mars and Jupiter during the formation of the Solar System, hence the rocky planets Mercury, Venus, Earth and Mars formed within the line, and the gaseous planets Jupiter, Saturn, Uranus and Neptune formed outside.

    [2] 1 au, or one astronomical unit, is the mean distance between the Earth and the Sun, around 149.6 million kilometers. This unit is typically used to describe distances measured within the Solar System and planetary systems around other stars.

    [3] Resolution is the ability to discern that objects are separate. To the human eye, several bright torches at a distance would seem like a single glowing spot, and only at closer quarters would each torch be distinguishable. The same principle applies to telescopes, and these new observations have exploited the exquisite resolution of ALMA in its long baseline modes. The resolution of ALMA at the distance of V883 Orionis is about 12 au — enough to resolve the water snow line at 40 au in this outbursting system, but not for a typical young star.

    [4] Stars are believed to acquire most of their mass during these short but intense accretion events.

    Additional information

    These observation results were published in a paper entitled “Imaging the water snow-line during a protostellar outburst” to appear in the journal Nature on 14 July, 2016.

    The research team is composed of Lucas A. Cieza [1,2], Simón Casassus [2,3], John Tobin [4], Steven Bos [4], Jonathan P. Williams [5], Sebastián Pérez [2,3], Zhaohuan Zhu [6], Claudio Cáceres [2,7], Héctor Cánovas [2,7], Michael M. Dunham [8], Antonio Hales [9], José L. Prieto [1], David A. Príncipe [1,2], Matthias R. Schreiber [2,7], Dary Ruiz-Rodríguez [10] and Alice Zurlo [1,2,3].

    [1] Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Santiago, Chile.

    [2] Millenium Nucleus “Protoplanetary Disks in ALMA Early Science”, Santiago, Chile.

    [3] Departamento de Astronomía, Universidad de Chile, Santiago, Chile.

    [4] Leiden Observatory, Leiden University, Leiden, The Netherlands.

    [5] Institute for Astronomy, University of Hawaii at Manoa, Honolulu, USA.

    [6] Department of Astrophysical Sciences, Princeton University, Princeton, USA.

    [7] Departamento de Física y Astronomía, Universidad de Valparaíso, Valparaíso, Chile.

    [8] Harvard-Smithsonian Center for Astrophysics, Cambridge, USA.


    [9] Joint ALMA Observatory, Santiago, Chile.

    [10] Australian National University, Mount Stromlo Observatory, Canberra, Australia.

    See the full article here .

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

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

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    ESO 50

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  • richardmitnick 10:00 am on July 9, 2016 Permalink | Reply
    Tags: , ALMA finds a swirling cool jet that reveals a growing supermassive black hole, , , ONSALA, Radio Astronomy   

    From ONSALA: “ALMA finds a swirling cool jet that reveals a growing supermassive black hole” 

    1

    ONSALA

    7.4.16
    No writer credit found

    1
    1.Alma’s close-up view of the centre of galaxy NGC 1377 (upper left) reveals a swirling jet. In this colour-coded image, reddish gas clouds are moving away from us, bluish clouds towards us, relative to the galaxy’s centre. The Alma image shows light with wavelength around one millimetre from molecules of carbon monoxide (CO). A cartoon view (lower right) shows how these clouds are moving, this time seen from the side. ​CTIO/H. Roussel et al./ESO (left panel); Alma/ESO/NRAO/S. Aalto (top right panel); S. Aalto (lower right panel)

    A Chalmers-led team of astronomers have used the Alma telescope to make the surprising discovery of a jet of cool, dense gas in the centre of a galaxy located 70 million light years from Earth. The jet, with its unusual, swirling structure, gives new clues to a long-standing astronomical mystery – how supermassive black holes grow.

    A team of astronomers led by Susanne Aalto, professor of radio astronomy at Chalmers, has used the Alma telescope (Atacama Large Millimeter/submillimeter Array) to observe a remarkable structure in the centre of the galaxy NGC 1377, located 70 million light years from Earth in the constellation Eridanus (the River).

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

    The results are presented in a paper published in the June 2016 issue of the journal Astronomy and Astrophysics.

    “We were curious about this galaxy because of its bright, dust-enshrouded centre. What we weren’t expecting was this: a long, narrow jet streaming out from the galaxy nucleus”, says Susanne Aalto.

    2
    2. Alma’s close-up view of the centre of galaxy NGC 1377 reveals a swirling jet. In this colour-coded image, reddish gas clouds are moving away from us, bluish clouds towards us, relative to the galaxy’s centre. The image shows light with wavelength around one millimetre from molecules of carbon monoxide (CO).
    Image credit: ALMA/ESO/NRAO/S. Aalto & F. Costagliola

    The observations with Alma reveal a jet which is 500 light years long and less than 60 light years across, travelling at speeds of at least 800 000 kilometres per hour (500 000 miles per hour).

    Most galaxies have a supermassive black hole in their centres; these black holes can have masses of between a few million to a billion solar masses. How they grew to be so massive is a long-standing mystery for scientists.

    A black hole’s presence can be seen indirectly by telescopes when matter is falling into it – a process which astronomers call “accretion”. Jets of fast-moving material are typical signatures that a black hole is growing by accreting matter. The jet in NGC 1377 reveals the presence of a supermassive black hole. But it has even more to tell us, explains Francesco Costagliola (Chalmers and ORA-INAF, Italy), co-author on the paper.

    3
    3. This cartoon view shows how the clouds of material that make up the jet are moving outward from the central black hole, this time seen from the side. Red colours show clouds that are moving away from us, and blue colours show clouds that are moving towards us, relative to the black hole in the galaxy’s centre.
    Image credit: S. Aalto

    “The jets we usually see emerging from galaxy nuclei are very narrow tubes of hot plasma. This jet is very different. Instead it’s extremely cool, and its light comes from dense gas composed of molecules”, he says.

    The jet has ejected molecular gas equivalent to two million times the mass of the Sun over a period of only around half a million years – a very short time in the life of a galaxy. During this short and dramatic phase in the galaxy’s evolution, its central, supermassive black hole must have grown fast.

    “Black holes that cause powerful narrow jets can grow slowly by accreting hot plasma. The black hole in NGC1377, on the other hand, is on a diet of cold gas and dust, and can therefore grow – at least for now – at a much faster rate”, explains team member Jay Gallagher (University of Wisconsin-Madison).

    The motion of the gas in the jet also surprised the astronomers. The measurements with Alma are consistent with a jet that is precessing – swirling outwards like water from a garden sprinkler.

    “The jet’s unusual swirling could be due to an uneven flow of gas towards the central black hole. Another possibility is that the galaxy’s centre contains two supermassive black holes in orbit around each other”, says Sebastien Muller, Chalmers, also a member of the team.

    The discovery of the remarkable cool, swirling jet from the centre of this galaxy would have been impossible without Alma, concludes Susanne Aalto.

    “Alma’s unique ability to detect and measure cold gas is revolutionising our understanding of galaxies and their central black holes. In NGC 1377 we’re witnessing a transient stage in a galaxy’s evolution which will help us understand the most rapid and important growth phases of supermassive black holes, and the life cycle of galaxies in the universe”, she says.

    More about the research

    This research is presented in the article A precessing molecular jet signaling an obscured, growing supermassive black hole in NGC 1377?, published in the June 2016 issue of Astronomy and Astrophysics (http://dx.doi.org/10.1051/0004-6361/201527664).

    The team is composed of Susanne Aalto (Chalmers), Francesco Costagliola (Chalmers and ORA-INAF, Italy), Sebastien Muller (Chalmers), K, Sakamoto (Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan), Jay S. Gallagher (Department of Astronomy, University of Wisconsin-Madison), K. Dasyra (National and Kapodistrian​ University of Athens, Greece), K. Wada (Kagoshima University, Japan), F. Combes (Paris Observatory, France), S. Garcia-Burillo (Observatorio Astronomico Nacional (OAN)-Observatorio de Madrid, Spain), L. E. Kristensen (Harvard-Smithsonian Center for Astrophysics, USA), S. Martin (European Southern Observatory, Joint Alma Observatory and IRAM, France), P. van der Werf (Leiden Observatory, Netherlands), A. S. Evans (University of Virginia and Virginia and National Radio Astronomy Observatory, USA) and J. Kotilainen (Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Finland).

    See the full article here .

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    Onsala 20 meter telescope exterior Sweden
    Onsala 20 meter telescope Sweden

    Onsala Space Observatory (OSO), the Swedish National Facility for Radio Astronomy, provides scientists with equipment to study the Earth and the rest of the Universe. We operate several radio telescopes in Onsala, 45 km south of Göteborg, and take part in international projects. The observatory is a geodetic fundamental station. Examples of facilities and activities:

    The 20 and 25 m telescopes in Onsala: Studies of the birth and death of stars, and of molecules in the Milky Way and other galaxies.
    The LOFAR station in Onsala: One part of an international network of antennas for studies of, e.g., the early history of the Universe.
    VLBI: Telescopes in different countries are linked together for better resolution (“sharper images”) and for measurements of the Earth.
    SKA: Developing technology for the world’s largest radio telescope.
    APEX: Radio telescope in Chile for sub-millimetre waves. Research about everything from planets to the structure of the Universe.
    ALMA: Using and developing the Atacama Large Millimeter/submillimeter Array in Chile.
    Space geodesy: Radio telescopes (VLBI), satellites (e.g., GPS), gravimeters and tide gauges are used to measure, e.g., Earth’s rotation, movements in Earth’s crust, sea level, and water vapour in the atmosphere.
    Time keeping: Two hydrogen maser clocks and one cesium clock contribute to establishing the official Swedish time and international time.
    SALSA: Small radio telescopes in Onsala for educational purposes.
    Receiver development: Laboratories for development of sensitive radio receivers.

    Onsala Space Observatory is hosted by Department of Earth and Space Sciences at Chalmers University of Technology, and is operated on behalf of the Swedish Research Council. There are particularly strong links to the Department’s research groups in Advanced receiver development, Radio astronomy and astrophysics, Space geodesy and geodynamics, and Global environmental measurements and modelling.

    The observatory was founded in 1949 by professor Olof Rydbeck.

     
  • richardmitnick 6:59 am on July 6, 2016 Permalink | Reply
    Tags: , , , , Radio Astronomy   

    From RAS: “Earth-size telescope tracks the aftermath of a star being swallowed by a supermassive black hole” 

    Royal Astronomical Society

    Royal Astronomical Society

    05 July 2016
    Media contact

    Robert Cumming
    Communications Officer
    Onsala Space Observatory
    Chalmers University of Technology
    Sweden
    Tel: +46 70 493 3114 or +46 (0)31 772 5500
    robert.cumming@chalmers.se

    Science contact

    Jun Yang
    Onsala Space Observatory
    Chalmers University of Technology
    Sweden
    Tel: +46 (0)31 7725531
    jun.yang@chalmers.se

    Radio astronomers have used a radio telescope network the size of the Earth to zoom in on a unique phenomenon in a distant galaxy: a jet activated by a star being consumed by a supermassive black hole. The record-sharp observations reveal a compact and surprisingly slowly moving source of radio waves, with details published in a paper in the journal Monthly Notices of the Royal Astronomical Society. The results will also be presented at the European Week of Astronomy and Space Science in Athens, Greece, on Friday 8 July 2016.

    1
    This artist’s impression shows the remains of a star that came too close to a supermassive black hole. Extremely sharp observations of the event Swift J1644+57 with the radio telescope network EVN (European VLBI Network) have revealed a remarkably compact jet, shown here in yellow. Image credit: ESA/S. Komossa/Beabudai Design.

    The international team, led by Jun Yang (Onsala Space Observatory, Chalmers University of Technology, Sweden), studied the new-born jet in a source known as Swift J1644+57 with the European VLBI Network (EVN), an Earth-size radio telescope array.

    European VLBI
    European VLBI

    When a star moves close to a supermassive black hole it can be disrupted violently. About half of the gas in the star is drawn towards the black hole and forms a disc around it. During this process, large amounts of gravitational energy are converted into electromagnetic radiation, creating a bright source visible at many different wavelengths.

    One dramatic consequence is that some of the star’s material, stripped from the star and collected around the black hole, can be ejected in extremely narrow beams of particles at speeds approaching the speed of light. These so-called relativistic jets produce strong emission at radio wavelengths.

    The first known tidal disruption event that formed a relativistic jet was discovered in 2011 by the NASA satellite Swift. Initially identified by a bright flare in X-rays, the event was given the name Swift J1644+57. The source was traced to a distant galaxy, so far away that its light took around 3.9 billion years to reach Earth.

    Jun Yang and his colleagues used the technique of very long baseline interferometry (VLBI), where a network of detectors separated by thousands of kilometres are combined into a single observatory, to make extremely high-precision measurements of the jet from Swift J1644+57.

    2
    Three years of extremely precise EVN measurements of the jet from Swift J1644+5734 show a very compact source with no signs of motion. Lower panel: false colour contour image of the jet (the ellipse in the lower left corner shows the size of an unresolved source). Upper panel: position measurement with dates. One microarcsecond is one 3 600 000 000th part of a degree. Image credit: EVN/JIVE/J. Yang.

    “Using the EVN telescope network we were able to measure the jet’s position to a precision of 10 microarcseconds. That corresponds to the angular extent of a 2-Euro coin on the Moon as seen from Earth. These are some of the sharpest measurements ever made by radio telescopes”, says Jun Yang.

    Thanks to the amazing precision possible with the network of radio telescopes, the scientists were able to search for signs of motion in the jet, despite its huge distance.

    “We looked for motion close to the light speed in the jet, so-called superluminal motion. Over our three years of observations such movement should have been clearly detectable. But our images reveal instead very compact and steady emission – there is no apparent motion”, continues Jun Yang.

    The results give important insights into what happens when a star is destroyed by a supermassive black hole, but also how newly launched jets behave in a pristine environment. Zsolt Paragi, Head of User Support at the Joint Institute for VLBI ERIC (JIVE) in Dwingeloo, Netherlands, and member of the team, explains why the jet appears to be so compact and stationary.

    “Newly formed relativistic ejecta decelerate quickly as they interact with the interstellar medium in the galaxy. Besides, earlier studies suggest we may be seeing the jet at a very small angle. That could contribute to the apparent compactness”, he says.

    The record-sharp and extremely sensitive observations would not have been possible without the full power of the many radio telescopes of different sizes which together make up the EVN, explains Tao An from the Shanghai Astronomical Observatory, P.R. China.

    “While the largest radio telescopes in the network contribute to the great sensitivity, the larger field of view provided by telescopes like the 25-m radio telescopes in Sheshan and Nanshan (China), and in Onsala (Sweden) played a crucial role in the investigation, allowing us to simultaneously observe Swift J1644+57 and a faint reference source,” he says.

    Swift J1644+57 is one of the first tidal disruption events to be studied in detail, and it won’t be the last.

    “Observations with the next generation of radio telescopes will tell us more about what actually happens when a star is eaten by a black hole – and how powerful jets form and evolve right next to black holes”, explains Stefanie Komossa, astronomer at the Max Planck Institute for Radio Astronomy in Bonn, Germany.

    “In the future, new, giant radio telescopes like FAST (Five hundred meter Aperture Spherical Telescope) and SKA (Square Kilometre Array) will allow us to make even more detailed observations of these extreme and exciting events,” concludes Jun Yang.

    See the full article here .

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