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  • richardmitnick 6:51 am on May 27, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , , , , , , ,   

    From McGill: “Homing in on source of mysterious cosmic radio bursts” 

    McGill University

    McGill University

    4 Jan 2017
    No writer credit found

    1

    Astronomers have pinpointed for the first time the home galaxy of a Fast Radio Burst, moving scientists a step closer to detecting what causes these powerful but fleeting pulses of radio waves. FRBs, which last just a few thousandths of a second, have puzzled astrophysicists since their discovery a decade ago.

    “Now we know that at least one of these FRBs originated within a dwarf galaxy located some three billion light-years beyond our Milky Way galaxy,” said McGill University postdoctoral researcher Shriharsh Tendulkar. He and other astronomers presented the findings today at the meeting of the American Astronomical Society in Grapevine, Texas. Results of the research are also published in the journal Nature and in companion papers in The Astrophysical Journal Letters [Tendulkar, S. P., et al. 2017, ApJL, 834, L7. http://iopscience.iop.org/article/10.3847/2041-8213/834/2/L7%5D and [Marcote, B., et al. 2017, ApJL, 834, L8. http://iopscience.iop.org/article/10.3847/2041-8213/834/2/L8%5D.

    Until now, astronomers hadn’t even been able to determine with certainty whether FRBs come from within our galaxy or beyond. While the exact cause of the high-energy bursts remains unclear, the fact that this particular FRB comes from a distant dwarf galaxy represents “a huge advance in our understanding of these events,” said Shami Chatterjee of Cornell University, another member of the international research team that produced the new results.

    A recurring FRB

    There are now 18 known FRBs. All were detected using single-dish radio telescopes that are unable to narrow down the object’s location with enough precision to allow other observatories to identify its host environment. Unlike all the others, however, one FRB, discovered in November of 2012 at the Arecibo Observatory in Puerto Rico, has recurred numerous times – a pattern first detected in late 2015 by McGill PhD student Paul Scholz.

    NAIC/Arecibo Observatory, Puerto Rico, USA

    The repeating bursts from this object, named FRB 121102 after the date of the initial burst, allowed astronomers to watch for it this year using the National Science Foundation’s (NSF) Karl G. Jansky Very Large Array (VLA), a multi-antenna radio telescope system with the resolving power, or ability to see fine detail, needed to precisely determine the object’s location in the sky.

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

    In 83 hours of observing time over six months in 2016, the VLA detected nine bursts from FRB 121102.

    Using the precise VLA position, Tendulkar and other researchers used the Gemini North telescope in Hawaii to make a visible-light image that identified a faint dwarf galaxy at the location of the bursts. Spectroscopic data from Gemini also enabled the researchers to determine that the dwarf galaxy is more than 3 billion light-years from Earth.

    A humble, unassuming host galaxy

    “The host galaxy for this FRB appears to be a very humble and unassuming dwarf galaxy, which is less than 1% of the mass or our Milky Way galaxy,” Tendulkar says. “That’s surprising. One would generally expect most FRBs to come from large galaxies which have the largest numbers of stars and neutron stars — remnants of massive stars. This dwarf galaxy has fewer stars, but is forming stars at a high rate, which may suggest that FRBs are linked to young neutron stars. There are also two other classes of extreme events — long duration gamma-ray bursts and superluminous supernovae — that frequently occur in dwarf galaxies, as well. This discovery may hint at links between FRBs and those two kinds of events.”

    In addition to detecting the bright bursts from FRB 121102, the VLA observations also revealed an ongoing, persistent source of weaker radio emission in the same region.

    Next, a team of observers used the multiple radio telescopes of the European VLBI Network (EVN), along with the 1,000-foot-diameter William E. Gordon Telescope of the Arecibo Observatory, and the NSF’s Very Long Baseline Array (VLBA) to determine the object’s position with even greater accuracy.

    European VLBI

    “These ultra-high precision observations showed that the bursts and the persistent source must be within 100 light-years of each other,” said Jason Hessels, of the Netherlands Institute for Radio Astronomy and the University of Amsterdam.

    “We think that the bursts and the continuous source are likely to be either the same object or that they are somehow physically associated with each other,” said Benito Marcote, of the Joint Institute for VLBI ERIC, Dwingeloo, Netherlands.

    CHIME could help solve puzzle

    The top candidates, the astronomers suggested, are a young neutron star, possibly a highly-magnetic magnetar, surrounded by either material ejected by a supernova explosion or material ejected by a resulting pulsar, or an active supermassive black hole in the galaxy, with radio emission coming from jets of material emitted from the region surrounding the black hole.

    Now, thanks to new images from the Hubble Space Telescope and the 8.2-metre Subaru Telescope in Hawaii, the McGill researchers and a separate team from Tohoku University in Japan have honed in on the source of FRB 121102 even further – to a giant stellar nursery near the centre of the distant dwarf galaxy.

    NASA/ESA Hubble Telescope


    NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA

    4
    5.25.17 New Scientist.Making signals from afar.John R. Foster/SCIENCE PHOTO LIBRARY

    “The Hubble and Subaru images show that the star-forming complex lies on the small galaxy’s outskirts,” Ken Croswell reports for New Scientist.

    “There is still a lot of work to do to unravel the mystery surrounding FRBs,” says McGill physics professor Victoria Kaspi, a senior member of the international team that conducted the new studies. “But identifying the host galaxy for this repeating FRB marks a big step toward solving the puzzle.”

    The Canadian Hydrogen Intensity Mapping Experiment (CHIME), an interferometric radio telescope in British Columbia, could help answer remaining questions, Kaspi notes. CHIME will survey half the sky each day, potentially enabling it to detect dozens of FRBs per day, she says. “Once we understand the origin of this phenomenon, it could provide us with a new and valuable probe of the Universe.”

    CHIME Canadian Hydrogen Intensity Mapping Experiment A partnership between the University of British Columbia McGill University

    The research was supported in part by the National Research Council of Canada, the Natural Sciences and Engineering Research Council of Canada, the Canadian Institute for Advanced Research, the Lorne Trottier Chair in Astrophysics and Cosmology, the European Research Council, and the National Science Foundation (U.S.).

    See the full article here .

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    All about McGill

    With some 300 buildings, more than 38,500 students and 250,000 living alumni, and a reputation for excellence that reaches around the globe, McGill has carved out a spot among the world’s greatest universities.
    Founded in Montreal, Quebec, in 1821, McGill is a leading Canadian post-secondary institution. It has two campuses, 11 faculties, 11 professional schools, 300 programs of study and some 39,000 students, including more than 9,300 graduate students. McGill attracts students from over 150 countries around the world, its 8,200 international students making up 21 per cent of the student body.

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  • richardmitnick 11:26 am on May 17, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , , , , , Maura McLaughlin, , , ,   

    From Physics: Women in STEM – “Q and A: Catching a Gravitational Wave with a Pulsar’s Beam” Maura McLaughlin 

    Physics LogoAbout Physics

    Physics Logo 2

    Physics

    May 12, 2017
    Katherine Wright

    Maura McLaughlin explains how the electromagnetic signals from fast-spinning neutron stars could be used to detect gravitational waves.

    1
    Maura McLaughlin. Greg Ellis/West Virginia University

    Pulsars captivate Maura McLaughlin, a professor at West Virginia University. These highly magnetized neutron stars flash beams of electromagnetic radiation as they spin. And with masses equivalent to that of the Sun, but diameters seventy thousand times smaller, they are—besides black holes—the densest objects in the Universe. Astrophysicists still have many questions about pulsars, ranging from how they emit electromagnetic radiation to why they are so incredibly dense. But it’s exploiting the highly stable, periodic electromagnetic signals of pulsars to study gravitational waves that currently has McLaughlin hooked. In an interview with Physics, she explained where her fascination with pulsars came from, what gravitational-wave sources she hopes to detect, and why she recently visited Washington, D.C., to talk with members of Congress.

    With the 2015 detection of gravitational waves, it’s obviously an exciting time to work in astrophysics. But what initially drew you to the field and to pulsars?

    The astrophysicist Alex Wolszczan. I met him in the early 90s while I was an undergrad at Penn State, and just after he had discovered the first extrasolar planets. These planets were orbiting a pulsar—lots of people don’t know that. I found this pulsar system fascinating and ended up working with Wolszczan one summer as a research assistant. I got to go to Puerto Rico to observe pulsars at the Arecibo Observatory, which is the biggest telescope in the world. The experience was really cool.
    How do researchers detect gravitational waves with pulsars?

    The collaboration that I’m part of—NANOGrav—is searching for changes in the travel time of the pulsar’s radio emission due to the passing of gravitational waves.

    2

    NANOGrave Gravitational waves JPL-Caltech David Champion

    When a gravitational wave passes between us and the pulsar, it stretches and squeezes spacetime, causing the pulse to arrive a bit earlier or later than it would in the absence of the wave. We time the arrival of pulsar signals for years to try to detect these small changes.
    What gravitational-wave-producing events do you expect to detect with pulsars? Could you see the same events as LIGO did?

    LIGO is sensitive to very short time-scale gravitational waves, on the order of milliseconds to seconds, while our experiment is sensitive to very long time-scale gravitational waves, on the order of years. We could never detect gravitational waves from two stellar-mass black holes merging—the time scale of the event is just too short. But we will be able to detect waves from black hole binaries in their inspiralling stage, when they’re still orbiting each other with periods of years. Also, our approach can only detect black holes that are much more massive that those LIGO observed. Our primary targets are supermassive black holes, even more massive than the one at the core of the Milky Way.


    Caltech/MIT Advanced aLigo Hanford, WA, USA installation


    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project


    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

    ESA/eLISA the future of gravitational wave research

    LIGO is basically probing the evolution and end products of stars, whereas our experiment is probing the evolution of galaxies and the cosmos. We’ll be able to look way back in time at the processes by which galaxies formed through mergers.
    The first detection of gravitational waves was front-page news. What impact has it had on your research?

    I, and others in NANOGrav, got lots of condolences after LIGO’s detection, like “oh we’re sorry you weren’t first.” But it’s been good for us. It has really spurred us on to make a detection. And it has made us more optimistic—if it worked for LIGO it should work for us, as our methods are rooted in the same principles. None of us doubted gravitational waves existed, but as far as funding agencies and the public go, LIGO’s detection makes a big difference. Now people can’t say, “Who knows if these things exist?” or “Who knows if these methods work?” LIGO’s detection has shown they do exist and the methods do work.

    Apart from doubters, what other challenges do you face with your pulsar experiment?

    Right now, our most significant challenge is that our radio telescopes are in danger of being shut down. Both Arecibo and the Green Bank Telescope (GBT) in West Virginia are suffering significant funding cuts.

    NAIC/Arecibo Observatory, Puerto Rico, USA



    GBO radio telescope, Green Bank, West Virginia, USA

    Many of our NANOGrav discussions lately are about what we can do to retain access to these telescopes. Losing one of these telescopes would reduce our experiment’s sensitivity by roughly half and increase the time to detection by at least several years. If we lose both, our project is dead in the water. Arecibo and GBT are currently the two most sensitive radio telescopes in the world . I think its crazy that they are possibly being shut down.

    [Do not forget FAST-China]

    FAST radio telescope, now operating, located in the Dawodang depression in Pingtang county Guizhou Province, South China

    What are you doing to address the problem?

    I recently spent two days on Capitol Hill in Washington, D.C., talking to senators and House representatives trying to make the case to keep GBT open. Most of the politicians actually agreed it should stay open; it’s just a matter of funding. Science in general just doesn’t have enough funding.

    How do you frame the issues when talking to politicians about science?

    I try really hard to stress the opportunities for training students, the infrastructure, and the number of people who work at these telescopes. The technologies developed at the facilities are cutting edge and can be used for more than studying space. The science is incredibly interesting, but that in itself doesn’t always appeal to everybody.

    With the current administration, arguments of US prominence are also really valuable. China [has built ans is operating] a bigger telescope than Arecibo, and soon we won’t have the largest radio telescope in the world. Right now we are world leaders, but if the US wants to keeps its dominance then these telescopes have to remain open.

    With the challenges you face, what would you say to someone thinking of joining this field?

    Despite uncertainties with the telescopes, the future is bright. Now is a really good time to join the field: we’re going to make a detection any day now.

    See the full article here .

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    Physicists are drowning in a flood of research papers in their own fields and coping with an even larger deluge in other areas of physics. How can an active researcher stay informed about the most important developments in physics? Physics highlights a selection of papers from the Physical Review journals. In consultation with expert scientists, the editors choose these papers for their importance and/or intrinsic interest. To highlight these papers, Physics features three kinds of articles: Viewpoints are commentaries written by active researchers, who are asked to explain the results to physicists in other subfields. Focus stories are written by professional science writers in a journalistic style and are intended to be accessible to students and non-experts. Synopses are brief editor-written summaries. Physics provides a much-needed guide to the best in physics, and we welcome your comments (physics@aps.org).

     
  • richardmitnick 6:12 pm on March 7, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , , ,   

    From APS: “Gravitational Waves: Hints, Allegations, and Things Left Unsaid” 

    AmericanPhysicalSociety

    American Physical Society

    APS April Meeting 2017

    If the APS April Meeting 2016 was a champagne-soaked celebration for gravitational wave scientists, the 2017 meeting was more like spring training — there was lots of potential, but the real action is yet to come.



    Caltech/MIT Advanced aLigo Hanford, WA, USA installation

    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    The Laser Interferometer Gravitational-Wave Observatory, or LIGO, launched the era of gravitational wave astronomy in February 2016 with the announcement of a collision between two black holes observed in September 2015. “I’m contractually obligated to show the slide [of the original detection] at any LIGO talk for at least another year,” joked Jocelyn Read, a physicist at California State University, Fullerton, during her presentation at this year’s meeting.

    The scientific collaboration that operates the two LIGO detectors netted a second merger between slightly smaller black holes on December 26, 2015. (A third “trigger” showed up in LIGO data on October 12, 2015, but ultimately did not meet the stringent “five-sigma” statistical significance standard that physicists generally insist on.)

    The detectors then went offline in January 2016 for repairs and upgrades. The second observing run began on November 30, but due to weather-related shutdowns and other logistical hurdles, the two detectors had operated simultaneously on only 12 days as of this year’s meeting, which limited the experiment’s statistical power. Collaboration members said they had no new detections to announce.

    Instead, scientists focused on sharpening theoretical estimates of how often various events occur. In particular, they are eager to see collisions involving neutron stars, which lack sufficient mass to collapse all the way to a black hole. Neutron star collisions are thought to be plentiful, but would emit weaker gravitational waves than do mergers of more massive black holes, so the volume of space the LIGO detectors can scan for such events is smaller.

    Even with recent upgrades, failure to detect a neutron star merger during the current observing run would not rule out existing models, said Read. But she added that with future improvements and the long-anticipated addition of Virgo, a LIGO-like detector based in Cascina, Italy, neutron stars should soon come out of hiding.



    VIRGO Gravitational Wave interferometer, near Pisa, Italy [Not yet operational]

    “We’re expecting that with a little more volume and a little more time, we’re going to be starting to make some astrophysically interesting statements.”

    LIGO scientists are also looking for signals from individual pulsars — rapidly rotating neutron stars that are observed on earth as pulses of radio waves. A bump on a pulsar’s surface should produce gravitational waves, but so far, no waves with the right shape have been picked up. This absence puts a limit on the size of any irregularities and on the emission power of gravitational waves from nearby pulsars such as the Crab and Vela pulsars, said Michael Landry, head of the Hanford LIGO observatory, and could soon start putting limits on more distant ones.

    Presenters dropped a few hints of possible excitement to come. LIGO data taken through the end of January produced two short signals that were unusual enough to exceed the experiment’s “false alarm” threshold — signals with shapes and strengths expected to show up once a month or less by chance alone. Both LIGO collaboration members and astronomers at conventional telescopes are investigating the data to determine whether they represent real events.

    For now, potential events will continue to be scrutinized by collaboration members, and released to the public via announcements coming months after initial detection. But LIGO leaders expect to shorten the lag time as detections become more frequent, perhaps eventually putting out monthly updates. “We hope to make it quicker,” said LIGO collaboration spokesperson Gabriela González, a physicist at Louisiana State University in Baton Rouge.

    LIGO is not the only means by which scientists are searching for gravitational waves. Some scientists are using powerful radio telescopes to track signals emanating from dozens of extremely fast-rotating pulsars. A specific pattern of correlations between tiny hiccups in the arrival times of these pulses would be a signature of long-wavelength gravitational waves expected from mergers of distant supermassive black holes.

    Teams in the U.S., Europe, and Australia have monitored pulsars for more than a decade, so far without positive results. But in an invited talk, Laura Sampson of Northwestern University in Evanston, Illinois, coyly announced “hints of some interesting signals.” With 11 years of timing data from 18 pulsars tracked by the Green Bank Telescope in West Virginia and the Arecibo Telescope in Puerto Rico, Sampson and other scientists affiliated with a collaboration called NANOGrav have eked out a result with a statistical significance of around 1.5 to 2 sigma.



    GBO radio telescope, Green Bank, West Virginia, USA


    NAIC/Arecibo Observatory, Puerto Rico, USA

    Data from the Green Bank Telescope in West Virginia and Arecibo Telescope in Puerto Rico help researchers use pulsars to study gravitational waves.

    “It’s the first hint we’ve ever had that there might be a signal in the data,” Sampson said. “Everything we’ve done before was straight-up limits.”

    As NANOGrav continues to gather data, their signal could grow toward the 5-sigma gold standard, or it could vanish. Sampson and her colleagues hope to have an answer in the next year or two. “This is of course very exciting news,” said Gonzalez.

    See the full article here .

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    Physicists are drowning in a flood of research papers in their own fields and coping with an even larger deluge in other areas of physics. How can an active researcher stay informed about the most important developments in physics? Physics highlights a selection of papers from the Physical Review journals. In consultation with expert scientists, the editors choose these papers for their importance and/or intrinsic interest. To highlight these papers, Physics features three kinds of articles: Viewpoints are commentaries written by active researchers, who are asked to explain the results to physicists in other subfields. Focus stories are written by professional science writers in a journalistic style and are intended to be accessible to students and non-experts. Synopses are brief editor-written summaries.

     
  • richardmitnick 1:14 pm on February 15, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , Comet 45P/Honda-Mrkos-Pajdusakova,   

    From SPACEREF: “Arecibo Observatory Images Comet 45P/Honda-Mrkos-Pajdusakova” 

    SpaceRef

    SpaceRef

    February 15, 2017
    Keith Cowing

    1
    Comet 45P/Honda-Mrkos-Pajdusakova. ©Arecibo Observatory

    NAIC/Arecibo Observatory, Puerto Rico, USA
    NAIC/Arecibo Observatory, Puerto Rico, USA

    Though not visible to the naked eye or even with binoculars, the green-tailed Comet 45P/Honda-Mrkos-Pajdusakova (HMP) did not escape the gaze of the world-renowned Arecibo Observatory.

    Scientists from the University of Arizona’s Lunar and Planetary Laboratory (LPL) and the Universities Space Research Association (USRA) at Arecibo Observatory have been studying the comet with radar to better understand its solid nucleus and the dusty coma that surrounds it.

    “Comets are remnants of the planet forming process and are part of a group of objects made of water ice and rocky material that formed beyond Neptune,” noted Dr. Ellen Howell, scientist at LPL and the leader of the observing campaign at Arecibo. “Studying these objects gives us an idea of how the outer reaches of our solar system formed and evolved over time.”

    Studying the comet with radar not only very precisely determines its orbit, allowing scientists to better predict its location in the future, but also gives a glimpse of the typically unseen part, the comet’s nucleus, which is usually hidden behind the cloud of gas and dust that makes up the its coma and tail.

    “The Arecibo Observatory planetary radar system can pierce through the comet’s coma and allows us to study the surface properties, size, shape, rotation, and geology of the comet nucleus,” said Dr. Patrick Taylor, USRA scientist and Group Lead for Planetary Radar at Arecibo. “We gain roughly the same amount of knowledge from a radar observation as a spacecraft flyby of the same object, but at considerably less cost.”

    In fact, the new radar observations have revealed Comet 45P/HMP to be somewhat larger than previously estimated. The radar images suggest a size of about 1.3 km (0.8 mi) and that it rotates about once every 7.6 hours. “We see complex structures and bright regions on the comet and have been able to investigate the coma with radar,” indicated Cassandra Lejoly, graduate student at the University of Arizona.

    This comet is only the seventh imaged using radar because comets rarely come close enough to the Earth to get such detailed radar images. In fact, though 45P/HMP has an orbital period of about 5.3 years, it rarely passes close to Earth, as it is doing now. Comet 45P is one of a group of comets called Jupiter family comets (JFCs), whose orbits are controlled by Jupiter’s gravity and typically orbit the Sun about every 6 years.

    Comet 45P/HMP, which is passing by Earth at a speed of about 23 km/s (relative to Earth) and a close approach of about 32 Earth-Moon distances, will be observed widely at different wavelengths to characterize the gas and dust emanating from the nucleus that forms the coma. As comets orbit the Sun, the ices sublime from solids to gases and escape the nucleus. The nucleus gradually shrinks and will disappear completely within in less than a million years.

    Radar observations at Arecibo of Comet 45P/HMP began on February 9, 2017, and will continue through February 17, 2017.

    The Arecibo Observatory is a facility of the National Science Foundation operated under cooperative agreement by SRI International in alliance with the Universities Space Research Association and Universidad Metropolitana. The Planetary Radar Program at Arecibo is fully funded by NASA through grants from the Near-Earth Object Observations program and managed by USRA.

    See the full article here.

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  • richardmitnick 3:11 pm on January 18, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , , , Galaxy Murder Mystery, ,   

    From ICRAR: “Galaxy Murder Mystery” 

    ICRAR Logo
    International Centre for Radio Astronomy Research

    January 17, 2017
    Mr Toby Brown (ICRAR-UWA, Swinburne University of Technology)
    E: toby.brown@icrar.org
    M: +61 6488 7753

    Dr Barbara Catinella (ICRAR-UWA)
    E: barbara.catinella@icrar.org
    Tel: +972 89346511

    Pete Wheeler—Media Contact, ICRAR
    E: pete.wheeler@icrar.org
    M: +61 423 982 018

    1
    This artist’s impression shows the spiral galaxy NGC 4921 based on observations made by the Hubble Space Telescope. Credit: ICRAR, NASA, ESA, the Hubble Heritage Team (STScI/AURA)

    It’s the big astrophysical whodunnit. Across the Universe, galaxies are being killed and the question scientists want answered is, what’s killing them?

    New research published today by a global team of researchers, based at the International Centre for Radio Astronomy Research (ICRAR), seeks to answer that question. The study reveals that a phenomenon called ram-pressure stripping is more prevalent than previously thought, driving gas from galaxies and sending them to an early death by depriving them of the material to make new stars.

    The study of 11,000 galaxies shows their gas—the lifeblood for star formation—is being violently stripped away on a widespread scale throughout the local Universe.

    Toby Brown, leader of the study and PhD candidate at ICRAR and Swinburne University of Technology, said the image we paint as astronomers is that galaxies are embedded in clouds of dark matter that we call dark matter halos.

    Dark matter is the mysterious material that despite being invisible accounts for roughly 27 per cent of our Universe, while ordinary matter makes up just 5 per cent. The remaining 68 per cent is dark energy.

    “During their lifetimes, galaxies can inhabit halos of different sizes, ranging from masses typical of our own Milky Way to halos thousands of times more massive,” Mr Brown said.

    “As galaxies fall through these larger halos, the superheated intergalactic plasma between them removes their gas in a fast-acting process called ram-pressure stripping.

    “You can think of it like a giant cosmic broom that comes through and physically sweeps the gas from the galaxies.”

    Mr Brown said removing the gas from galaxies leaves them unable to form new stars.

    “It dictates the life of the galaxy because the existing stars will cool off and grow old,” he said.

    “If you remove the fuel for star formation then you effectively kill the galaxy and turn it into a dead object.”

    ICRAR researcher Dr Barbara Catinella, co-author of the study, said astronomers already knew ram-pressure stripping affected galaxies in clusters, which are the most massive halos found in the Universe.

    “This paper demonstrates that the same process is operating in much smaller groups of just a few galaxies together with much less dark matter,” said Mr. Brown. “Most galaxies in the Universe live in these groups of between two and a hundred galaxies,” he said.

    “We’ve found this removal of gas by stripping is potentially the dominant way galaxies are quenched by their surrounds, meaning their gas is removed and star formation shuts down.”

    The study was published in the journal Monthly Notices of the Royal Astronomical Society. It used an innovative technique combining the largest optical galaxy survey ever completed—the Sloan Digital Sky Survey—with the largest set of radio observations for atomic gas in galaxies —the Arecibo Legacy Fast ALFA survey.

    SDSS Telescope at Apache Point, NM, USA
    SDSS Telescope at Apache Point, NM, USA
    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey
    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    NAIC/Arecibo Observatory, Puerto Rico, USA
    NAIC/Arecibo Observatory, Puerto Rico, USA
    3
    The Arecibo Legacy Fast ALFA Survey

    Mr Brown said the other main process by which galaxies run out of gas and die is known as strangulation.

    “Strangulation occurs when the gas is consumed to make stars faster than it’s being replenished, so the galaxy starves to death,” he said.

    “It’s a slow-acting process. On the contrary, what ram-pressure stripping does is bop the galaxy on the head and remove its gas very quickly—of the order of tens of millions of years—and astronomically speaking that’s very fast.”

    See the full article here .

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    ICRAR is an equal joint venture between Curtin University and The University of Western Australia with funding support from the State Government of Western Australia. The Centre’s headquarters are located at UWA, with research nodes at both UWA and the Curtin Institute for Radio Astronomy (CIRA).
    ICRAR has strong support from the government of Australia and is working closely with industry and the astronomy community, including CSIRO and the Australian Telescope National Facility, iVEC, and the international SKA Project Office (SPO), based in the UK.

    ICRAR is:

    Playing a key role in the international Square Kilometre Array (SKA) project, the world’s biggest ground-based telescope array.

    SKA Square Kilometer Array
    Attracting some of the world’s leading researchers in radio astronomy, who will also contribute to national and international scientific and technical programs for SKA and ASKAP.
    Creating a collaborative environment for scientists and engineers to engage and work with industry to produce studies, prototypes and systems linked to the overall scientific success of the SKA, MWA and ASKAP.

    SKA Murchison Widefield Array
    A Small part of the Murchison Widefield Array

    Enhancing Australia’s position in the international SKA program by contributing to the development process for the SKA in scientific, technological and operational areas.
    Promoting scientific, technical, commercial and educational opportunities through public outreach, educational material, training students and collaborative developments with national and international educational organisations.
    Establishing and maintaining a pool of emerging and top-level scientists and technologists in the disciplines related to radio astronomy through appointments and training.
    Making world-class contributions to SKA science, with emphasis on the signature science themes associated with surveys for neutral hydrogen and variable (transient) radio sources.
    Making world-class contributions to SKA capability with respect to developments in the areas of Data Intensive Science and support for the Murchison Radio-astronomy Observatory.

     
  • richardmitnick 3:21 pm on January 5, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , , , , ,   

    From USRA: “Arecibo Observatory casts new light on cosmic microwave background observed by WMAP and PLANCK spacecraft” 

    usra-bloc

    USRA

    January 4, 2017
    PR Contact: Suraiya Farukhi
    sfarukhi@usra.edu
    Universities Space Research Association
    410-740-6224 (o)
    443-812-6945 (c)

    Technical Contact: Joan Schmelz
    jschmelz@usra.edu
    Universities Space Research Association
    787-878-2612 x603

    NAIC/Arecibo Observatory, Puerto Rico, USA
    NAIC/Arecibo Observatory, Puerto Rico, USA

    Arecibo Observatory observations of galactic neutral hydrogen structure confirm the discovery of an unexpected contribution to the measurements of the cosmic microwave background observed by the WMAP and Planck spacecraft.

    NASA WMAP satellite
    NASA WMAP satellite

    ESA/Planck
    “ESA/Planck

    An accurate understanding of the foreground (galactic) sources of radiation observed by these two spacecraft is essential for extracting information about the small-scale structure in the cosmic microwave background believed to be indicative of events in the early universe.

    Cosmic Microwave Background WMAP
    Cosmic Microwave Background WMAP

    CMB per ESA/Planck
    CMB per ESA/Planck

    The new source of radiation in the 22 to 100 GHz range observed by WMAP and Planck appears to be emission from cold electrons (known as free-free emission). While cosmologists have corrected for this type of radiation from hot electrons associated with galactic nebulae where the source temperatures are thousands of degrees, the new model requires electron temperatures more like a few 100 K.

    The spectrum of the small-scale features observed by WMAP and Planck in this frequency range is very nearly flat — a finding consistent with the sources being associated with the Big Bang. At first glance it appears that the spectrum expected from the emission by cold galactic electrons, which exist throughout interstellar space, would be far too steep to fit the data. However, if the sources of emission have a small angular size compared with the beam width used in the WMAP and Planck spacecraft, the signals they record would be diluted. The beam widths increase with lower frequency, and the net result of this “beam dilution” is to produce an apparently flat spectrum in the 22 to 100 GHz range.

    “It was the beam dilution that was the key insight,” noted Dr. Gerrit Verschuur, astronomer emeritus at the Arecibo Observatory and lead author on the paper. “Emission from an unresolved source could mimic the flat spectrum observed by WMAP and Planck.”

    The model invoking the emission from cold electrons not only gives the observed flat spectrum usually attributed to cosmic sources but also predicts values for the angular scale and temperature for the emitting volumes. Those predictions can then be compared with observations of galactic structure revealed in the Galactic Arecibo L-Band Feed Array (GALFA) HI survey.

    “The interstellar medium is much more surprising and important than we have given it credit for,” noted Dr. Joshua Peek, an astronomer at the Space Telescope Science Institute and a co-investigator on the GALFA-HI survey. “Arecibo, with its combination of large area and high resolution, remains a spectacular and cutting edge tool for comparing ISM maps to cosmological data sets.”

    The angular scales of the smallest features observed in neutral hydrogen maps made at Arecibo and the temperature of the apparently associated gas both match the model calculations extremely well. So far only three well-studied areas have been analyzed in such detail, but more work is being planned.

    “It was the agreement between the model predictions and the GALFA-HI observations that convinced me that we might be onto something,” noted Dr. Joan Schmelz, Director, Universities Space Research Association (USRA) at Arecibo Observatory and a coauthor on the paper. “We hope that these results help us understand the true cosmological nature of Planck and WMAP data.”

    The data suggest that the structure and physics of diffuse interstellar matter, in particular of cold hydrogen gas and associated electrons, may be more complex than heretofore considered. Such complexities need to be taken into account in order to produce better foreground masks for application to the high-frequency continuum observations of Planck and WMAP in the quest for a cosmologically significant signal.

    USRA’s Dr. Joan Schmelz will present these findings on January 4, 2017, at a press conference at the American Astronomical Society’s (AAS) meeting at Grapevine, Texas.

    The results were published in the Astrophysical Journal, December 1, 2016, in a paper entitled On the Nature of Small-Scale Structure in the Cosmic Microwave Background Observed by Planck and WMAP by G. L. Verschuur and J. T. Schmelz.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    USRA is an independent, nonprofit research corporation where the combined efforts of in-house talent and university-based expertise merge to advance space science and technology.

    SIGNIFICANCE & PURPOSE

    USRA was founded in 1969, near the beginning of the Space Age, driven by the vision of two individuals, James Webb (NASA Administrator 1961-1968) and Frederick Seitz (National Academy of Sciences President 1962-1969). They recognized that the technical challenges of space would require an established research base to develop novel concepts and innovative technologies. Together, they worked to create USRA to satisfy not only the ongoing need for innovation in space, but also the need to involve society more broadly so the benefits of space activities would be realized.

     
  • richardmitnick 3:11 pm on January 4, 2017 Permalink | Reply
    Tags: Arecibo Observatory, , , , ,   

    From NRAO: “Precise Location, Distance Provide Breakthrough in Study of Fast Radio Bursts” 

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    4 January 2017

    1
    Visible-light image of host galaxy.
    Credit: Gemini Observatory/AURA/NSF/NRC.

    For the first time, astronomers have pinpointed the location in the sky of a Fast Radio Burst (FRB), allowing them to determine the distance and home galaxy of one of these mysterious pulses of radio waves. The new information rules out several suggested explanations for the source of FRBs.

    “We now know that this particular burst comes from a dwarf galaxy more than three billion light-years from Earth,” said Shami Chatterjee, of Cornell University. “That simple fact is a huge advance in our understanding of these events,” he added. Chatterjee and other astronomers presented their findings to the American Astronomical Society’s meeting in Grapevine, Texas, in the scientific journal Nature, and in companion papers in the Astrophysical Journal Letters.

    Fast Radio Bursts are highly-energetic, but very short-lived (millisecond) bursts of radio waves whose origins have remained a mystery since the first one was discovered in 2007. That year, researchers scouring archived data from Australia’s Parkes Radio Telescope in search of new pulsars found the first known FRB — one that had burst in 2001.

    There now are 18 known FRBs. All were discovered using single-dish radio telescopes that are unable to narrow down the object’s location with enough precision to allow other observatories to identify its host environment or to find it at other wavelengths. Unlike all the others, however, one FRB, discovered in November of 2012 at the Arecibo Observatory in Puerto Rico, has recurred numerous times.

    NAIC/Arecibo Observatory, Puerto Rico, USA
    NAIC/Arecibo Observatory, Puerto Rico, USA

    The repeating bursts from this object, named FRB 121102 after the date of the initial burst, allowed astronomers to watch for it using the National Science Foundation’s (NSF) Karl G. Jansky Very Large Array (VLA), a multi-antenna radio telescope system with the resolving power, or ability to see fine detail, needed to precisely determine the object’s location in the sky.

    In 83 hours of observing time over six months in 2016, the VLA detected nine bursts from FRB 121102.

    “For a long time, we came up empty, then got a string of bursts that gave us exactly what we needed,” said Casey Law, of the University of California at Berkeley.

    “The VLA data allowed us to narrow down the position very accurately,” said Sarah Burke-Spolaor, of the National Radio Astronomy Observatory (NRAO) and West Virginia University.

    Using the precise VLA position, researchers used the Gemini North telescope in Hawaii to make a visible-light image that identified a faint dwarf galaxy at the location of the bursts. The Gemini observations also determined that the dwarf galaxy is more than 3 billion light-years from Earth.

    Gemini/North telescope at Mauna Kea, Hawaii, USA
    Gemini/North telescope at Mauna Kea, Hawaii, USA

    “Before we knew the distance to any FRBs, several proposed explanations for their origins said they could be coming from within or near our own Milky Way Galaxy. We now have ruled out those explanations, at least for this FRB,” said Shriharsh Tendulkar, of McGill University in Montreal, Canada.

    In addition to detecting the bright bursts from FRB 121102, the VLA observations also revealed an ongoing, persistent source of weaker radio emission in the same region.

    Next, a team of observers used the multiple radio telescopes of the European VLBI Network (EVN), along with the 1,000-foot-diameter William E. Gordon Telescope of the Arecibo Observatory, and the NSF’s Very Long Baseline Array (VLBA) to determine the object’s position with even greater accuracy.

    European VLBI
    European VLBI

    NRAO VLBA
    NRAO VLBA

    “These ultra high precision observations showed that the bursts and the persistent source must be within 100 light-years of each other,” said Jason Hessels, of the Netherlands Institute for Radio Astronomy and the University of Amsterdam.

    “We think that the bursts and the continuous source are likely to be either the same object or that they are somehow physically associated with each other,” said Benito Marcote, of the Joint Institute for VLBI ERIC, Dwingeloo, Netherlands.

    The top candidates, the astronomers suggested, are a neutron star, possibly a highly-magnetic magnetar, surrounded by either material ejected by a supernova explosion or material ejected by a resulting pulsar, or an active nucleus in the galaxy, with radio emission coming from jets of material emitted from the region surrounding a supermassive black hole.

    “We do have to keep in mind that this FRB is the only one known to repeat, so it may be physically different from the others,” cautioned Bryan Butler of NRAO.

    “Finding the host galaxy of this FRB, and its distance, is a big step forward, but we still have much more to do before we fully understand what these things are,” Chatterjee said.

    “This impressive result shows the power of several telescopes working in concert — first detecting the radio burst and then precisely locating and beginning to characterize the emitting source,” said Phil Puxley, a program director at the National Science Foundation that funds the VLA, VLBA, Gemini and Arecibo observatories. “It will be exciting to collect more data and better understand the nature of these radio bursts.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

    ALMA Array

    NRAO ALMA

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

    NRAO VLA
    NRAO VLA

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

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

     
  • richardmitnick 8:48 am on June 5, 2016 Permalink | Reply
    Tags: Arecibo Observatory, , , , , Uncertain Future for Earth’s Still Biggest Telescope   

    From nationalgeographics.com: “Uncertain Future for Earth’s Biggest Telescope” 

    National Geographic

    National Geographics

    06/4/2016
    Nadia Drake

    1
    The Arecibo Observatory, easily recognizable from feature films and a symbol of the search for extraterrestrial life, may not be around for much longer. A harsh funding climate is forcing the National Science Foundation to make some hard decisions about which facilities to keep around. (NSF/Wikimedia)

    Tucked into a sinkhole in the Puerto Rican jungle, the world’s largest single-dish radio telescope scans the skies for signs of distant galaxies, elusive gravitational waves, and the murmurs of extraterrestrial civilizations nearly 24 hours a day. For more than a half-century, whether those waves traveled to Earth from the far reaches of our universe or much closer to home, the Arecibo Observatory has been there to catch them.

    But the enormous telescope, with a dish that stretches 1,000 feet across, may not be around for much longer.

    On May 23, the National Science Foundation, which funds the majority of Arecibo’s annual $12 million budget, published a notice of intent to prepare an environmental impact statement related to the observatory’s future.

    That might sound innocuous – after all, isn’t it a good idea to study the context in which our science facilities exist? Yet it’s anything but benign. Putting that environmental assessment together is a crucial step NSF needs to take if it plans to yank funding from the observatory and effectively shut it down.

    “It appears that NSF is following the formal process established, in part, by the National Environmental Policy Act of 1969, for decommissioning of a federal facility,” says Robert Kerr, former director of the observatory. “The good folks at Arecibo are scared to death.”

    The decision to close Arecibo hasn’t been made yet, but the move follows an ominous drumbeat of similar announcements and reports that have accumulated over several years, most urging NSF to send its resources elsewhere. Now, options for Arecibo’s future range from continuing current operations to dismantling the telescope and returning the site to its natural state. It’s a decision NSF hopes to make — with input from the public — by the end of 2017, says Jim Ulvestad, director of NSF’s Division of Astronomical Sciences.

    2
    Above the 1000-foot dish, a 900-ton platform is suspended from three tall towers. (Nadia Drake)

    The most extreme option, which could include explosively demolishing the giant dish, might affect such things as ground water, air quality, and ecosystems – thus the importance of studying the environmental impact of potential futures, especially ones that involve shutting the telescope’s eyes.

    “On a practical level, the telescope would in time — perhaps a short time, given the tropical site — become very unsafe,” says Cornell University’s Don Campbell, a former observatory director. “Short of permanently guarding it, deconstruction would be necessary.”

    Not surprisingly, this notice of intent is causing significant concern among astronomers and the local community. Arecibo is the most sensitive radio telescope in the world; and despite its age, it’s still involved in world-class science, like the search for gravitational waves. Importantly, it also helps boost a sagging local economy, and has inspired many Puerto Ricans to pursue science and think about the mysteries of the universe.

    “Puerto Rico feels a sense of ownership and pride for the observatory,” says Emmanuel Donate, an astronomy graduate student at the University of Georgia who started a petition to keep the observatory funded. “I consider using it, especially in person as I’ve been doing the last couple weeks, one of the highlights of my life and a tremendous personal honor.”

    A Tropical Icon

    Construction at Arecibo began in 1960, when – among other things – the U.S. government wanted to find out if Soviet ICBMs could be detected using charged particles in their atmospheric wakes. The telescope didn’t work well at first, but after a few upgrades it was the most sensitive cosmic radio wave detector in the world. That’s not it’s only trick, though: In addition to collecting photons from space, Arecibo is also capable of sending radio waves into the cosmos, a talent scientists use to scrutinize potentially catastrophic asteroids on Earth-crossing orbits.

    3
    The Arecibo Observatory, as seen on Google Earth.

    In the intervening decades, Arecibo has been involved in loads of top-notch science, including work that was awarded a Nobel Prize. But it’s also become a recognizable symbol of humanity’s quest to understand our place in the cosmos (my dad, a former observatory director, used Arecibo to send Earth’s first intentional postcard to the stars in 1974), and is a semi-frequent character in popular films and TV series, including The X-Files, Contact, and GoldenEye.

    To say the telescope is iconic is not an overstatement.

    Stormclouds on the Horizon

    But a frustratingly flatlined budget is forcing the National Science Foundation to ration its resources. To do that, NSF relies on a somewhat contorted process of soliciting input from external reviews and panels, federal advisory boards, and the National Research Council’s decadal surveys, which prioritize science goals for the coming decade.

    “NSF, like most federal science agencies, has much more worthy science proposed to it than it is able to fund,” Ulvestad says. “Within the constraints of its resources, NSF responds as well as possible to those community and governmental science priorities and recommendations.”

    The most recent decadal survey, published in 2010, prioritized science requiring new facilities instead of experiments that could be conducted at places like Arecibo. That survey, in combination with the dismal funding situation, is what’s causing NSF to look for facilities to dump.

    4
    Arecibo’s dish is suspended above the floor of the natural depression it sits in. Beneath it, plants grow like crazy. (Nadia Drake)

    Despite its iconic status, Arecibo is an easy target – newer, shinier telescopes are coming online, and it’s got a relatively small number of users compared to optical telescopes across the United States, many of which are individually less expensive to run.

    Over the past decade, multiple panels have called for severe reductions in funding for the observatory, starting with a 2006 NSF review that recommended finding alternative sources of cash for Arecibo. “The [senior review] recommends closure after 2011 if the necessary support is not forthcoming,” the report says. “This raises the important question of the cost of decommissioning the telescope, which could be prohibitively large.”

    That review was followed by a 2012 assessment of the facilities funded by NSF’s astronomical sciences division. While somewhat less gloomy – the committee recommended keeping the observatory in NSF’s portfolio – the 2012 panel suggested revisiting Arecibo’s funding status later in the decade, “in light of the science opportunities and budget forecasts at that time.”

    NSF followed that review with a 2013 letter saying it would begin studying the costs and impact of decommissioning the giant telescope – a matter that would be complicated by the telescope’s history and location in a region of high biodiversity, “thus these reviews should be started as soon as practicable.”

    The cloudy outlook intensified this year, when NSF’s Astronomy and Astrophysics Advisory Committee urged the agency to proceed with divestment “as fast as is practical.” That was quickly followed by another NSF review that advised a 75% reduction in funding from the agency’s Atmospheric and Geospace Sciences division (AGS), slashing contributions to atmospheric research from $4.1 million to $1.1 million.

    And now, the sky is looking dark indeed.

    “The timing of the federal register announcement in juxtaposition with the AGS review is being received by most as the final death sentence for Arecibo,” Kerr says.

    Ulvestad says that before any such decision is reached, communities that rely on the observatory will have an opportunity to share their concerns. On June 7, the first of these meetings will take place in Puerto Rico, and a public comment period is open until June 23. After the results of the draft environmental impact statement are released, a 45-day public comment period will follow.

    And then? Either the storm will hit or it won’t.

    “To be fair to the NSF, AST and AGS are reacting to a very difficult budget situation — no significant increase in several years and none forecast,” Campbell says.

    Scanning the Cosmos

    Now, Arecibo’s projects include detecting mysterious bursts of radio waves coming from far, far away, testing cosmological models by studying small galaxies in the local universe, and studying those potentially planet-killing asteroids – as well as the moons of distant planets.

    “There is much concern, not just in the small bodies community, but in the planetary science community as a whole regarding the future of Arecibo,” says Nancy Chabot of the Johns Hopkins University Applied Physics Laboratory. Chabot chairs NASA’s Small Bodies Assessment Group, which published a report earlier this year urging NASA to continue supporting the observatory, in the name of preserving “the nation’s science and security interests.”

    Among astronomers, perceptions are that NSF’s move to decommission Arecibo has been gaining momentum as challenges from new facilities arise. One potential thorn in Arecibo’s side is ALMA, the ultrasensitive array of radio telescopes recently completed in the Chilean Atacama.

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array

    Some scientists speculate that with continued resources devoted to ALMA, NSF could be looking to share the relative wealth and spend its money on something other than radio. And that might make sense, especially given that China is nearly done constructing a single-dish radio telescope that will be larger than Arecibo. Called the Five-hundred-meter Aperture Spherical Telescope, the behemoth could possibly open its eyes this fall, though real science observations won’t begin right away.

    FAST Chinese Radio telescope under construction, Guizhou Province, China
    “FAST Chinese Radio telescope under construction, Guizhou Province, China

    Despite its size, FAST won’t necessarily be more sensitive than Arecibo, and it won’t have a built-in radar, which can be used to give the most accurate orbital information for asteroids which might impact the Earth.

    Cornell University’s Jim Cordes points out that newer facilities don’t necessarily have to replace older, high-quality telescopes, especially when those older facilities still provide unique capabilities. They can be complementary, he says, pointing out that scores of similar optical telescopes exist in tandem, such as the two nearly identical Keck telescopes at the summit of Hawaii’s Mauna Kea.

    Keck Observatory, Mauna Kea, Hawaii, USA
    Keck Observatory, Mauna Kea, Hawaii, USA

    “It’s sort of like there’s a disconnect in the way people think about radio telescopes and optical telescopes,” Cordes says.

    More importantly, Cordes notes, some experiments actually require multiple extremely sensitive telescopes. One of these, called NANOGrav, uses Arecibo and a telescope at the National Radio Astronomy Observatory in Green Bank, West Virginia to search for gravitational waves.

    NANOGrave Gravitational waves JPL-Caltech  David Champion
    NANOGrave Gravitational waves JPL-Caltech David Champion

    NRAO/GBT radio telescope
    NRAO/GBT radio telescope

    The project does this by observing pulsars, spinning stellar corpses that act as astronomical clocks. As these dense, dead stars rotate, they emit beams of radio waves that can be detected from Earth; gravitational waves, similar to those detected earlier this year by the LIGO collaboration, sweep through and disrupt the signals coming from those spinning clocks in observable ways…as long as a sharp set of eyes is paying attention.

    A National Inspiration?

    It seems clear that Arecibo won’t go down without a fight, but it’s not exactly clear what form that fight will take. Interestingly, former observatory director Robert Kerr threw one punch by beginning the process for listing Arecibo as a national historic site.

    “It was entirely my intention that the National Historic Registry be an impediment to site closure,” he says, adding that “others assisting with that application may have had other motivations, such as enhanced tourist appeal.”

    And NASA, which funds the planetary radar experiments at Arecibo, also may have something to say about NSF shutting down the facility. It’s also possible that another institution, or someone with enough spare cash might decide to step in.

    “I hope that they do find another institution to contribute to the costs but it will depend on the conditions,” Campbell says. “The alternative is grim for science, for Puerto Rico and, especially given Puerto Rico’s current situation, for the Observatory’s local staff. The staff are an incredible hard working and supportive group.”

    Indeed, generations of Puerto Ricans have visited the observatory, in addition to those who have worked, studied, and lived there.

    “I grew up in the city of Arecibo, I grew up knowing that in the mountains south of the city great science was being done,” says Pablo Llerandi-Román, a geologist at the University of Puerto Rico, Rio Piedras. For Llerandi, science became more than just a subject in school when he visited the observatory as a student and talked with the researchers on site. “If Arecibo shuts down,” he says, “A major aspect of my arecibeño and Puerto Rican scientist pride would be lost.”

    Carlos Estevez Galarza, a student at the University of Puerto Rico, says he hopes Puerto Ricans will one day be as celebrated for their commitment to science as they are for their passions for arts and sports – and he thinks the observatory plays an important role in that.

    “The Arecibo Observatory and its staff were the only ones who believed in me, when no one did,” Galarza says. He worked as a student research assistant at the observatory, studying Mars, and has since presented his work at international conferences and submitted his first paper to a science journal.

    “The most important thing about my experience at the Arecibo Observatory is that I found my purpose,” he continues. “There are many talented Puerto Rican students who deserve the chance that I had.”

    One of those students is still in high school. Now 16, Wilbert Andres Ruperto Hernandez wanted to be an astronaut as a kid – and he wanted to get some hands-on experience in science and engineering. So he enrolled in the Arecibo Observatory Space Academy, which offers high school students the opportunity to design experiments, then collect and analyze data. Now, Hernandez says, he wants to study mechanical engineering or space sciences in college, and has discovered a yearning to understand how the universe works – something that emerged while working with and talking to scientists at the observatory.

    “The fact that we have yet to discover and learn more about ourselves, where we live in and all the things that surround us, motivates me the most to investigate and study these fields,” he says. “Being part of Arecibo Observatory and AOSA has been the greatest experience in my life.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The National Geographic Society has been inspiring people to care about the planet since 1888. It is one of the largest nonprofit scientific and educational institutions in the world. Its interests include geography, archaeology and natural science, and the promotion of environmental and historical conservation.

     
  • richardmitnick 3:16 am on March 11, 2015 Permalink | Reply
    Tags: Arecibo Observatory, , ,   

    From NRAO- “Image Release: Venus, If You Will, as Seen in Radar with the GBT” 

    NRAO Icon
    National Radio Astronomy Observatory

    NRAO Banner

    March 9, 2015
    Charles Blue
    NRAO Public Information Officer
    (434) 296-0314; cblue@nrao.edu

    1
    A projection of the radar data of Venus collected in 2012. Striking surface features — like mountains and ridges — are easily seen. The black diagonal band at the center represents areas too close to the Doppler “equator” to obtain well-resolved image data. Credit: B. Campbell, Smithsonian, et al., NRAO/AUI/NSF, Arecibo

    From earthbound optical telescopes, the surface of Venus is shrouded beneath thick clouds made mostly of carbon dioxide. To penetrate this veil, probes like NASA’s Magellan spacecraft use radar to reveal remarkable features of this planet, like mountains, craters, and volcanoes.

    Recently, by combining the highly sensitive receiving capabilities of the National Science Foundation’s (NSF) Green Bank Telescope (GBT) and the powerful radar transmitter at the NSF’s Arecibo Observatory, astronomers were able to make remarkably detailed images of the surface of this planet without ever leaving Earth.

    Arecibo
    NSF’s Arecibo Observatory

    The radar signals from Arecibo passed through both our planet’s atmosphere and the atmosphere of Venus, where they hit the surface and bounced back to be received by the GBT in a process known as bistatic radar.

    This capability is essential to study not only the surface as it appears now, but also to monitor it for changes. By comparing images taken at different periods in time, scientists hope to eventually detect signs of active volcanism or other dynamic geologic processes that could reveal clues to Venus’s geologic history and subsurface conditions.

    High-resolution radar images of Venus were first obtained by Arecibo in 1988 and most recently by Arecibo and GBT in 2012, with additional coverage in the early 2000s by Lynn Carter of NASA’s Goddard Spaceflight Center in Greenbelt, Md. The first of those observations was an early science commissioning experiment for the GBT.

    “It is painstaking to compare radar images to search for evidence of change, but the work is ongoing. In the meantime, combining images from this and an earlier observing period is yielding a wealth of insight about other processes that alter the surface of Venus,” said Bruce Campbell, Senior Scientist with the Center for Earth and Planetary Studies at the Smithsonian’s National Air and Space Museum in Washington, D.C. A paper discussing the comparison between these two observations was accepted for publication in the journal Icarus.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

    ALMA Array
    NRAO ALMA

    NRAO GBT
    NRAO GBT

    NRAO VLA
    NRAO VLA

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

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

     
  • richardmitnick 5:43 pm on December 4, 2014 Permalink | Reply
    Tags: Arecibo Observatory, , , , , ,   

    From RAS: “Astronomers detect atomic hydrogen emission in galaxies at record breaking distances” 

    Royal Astronomical Society

    Royal Astronomical Society

    Wednesday, 03 December 2014
    Media contact (UK)

    Dr Robert Massey
    Royal Astronomical Society
    Tel: +44 (0)20 7734 3307 x214
    Mob: +44 (0)794 124 8035
    rm@ras.org.uk

    Science contact

    Dr Barbara Catinella
    Australian Research Council Future Fellow
    Centre for Astrophysics & Supercomputing
    Swinburne University of Technology
    Australia
    Tel: +61 3 9214 4918
    bcatinella@swin.edu.au

    Using the world’s largest radio telescope, two astronomers from Swinburne University of Technology in Australia have detected the faint signal emitted by atomic hydrogen gas in galaxies three billion light years from Earth, breaking the previous record distance by 500 million light years. Their results appear in a paper published in the journal Monthly Notices of the Royal Astronomical Society.

    a
    The 305-m Arecibo radio observatory in Puerto Rico, which was used to detect the hydrogen gas in these distant galaxies. Credit: Arecibo Observatory/NAIC.

    Using the 305-m diameter Arecibo radio telescope in Puerto Rico, Dr Barbara Catinella and Dr Luca Cortese measured the hydrogen gas content of nearly 40 galaxies at distances of up to three billion light years. By doing so, the two scientists found a unique population of galaxies hosting huge reservoirs of hydrogen gas, the fuel for forming new stars like our Sun.

    These very gas-rich systems each contain between 20 and 80 billion times the mass of the Sun in atomic gas. Such galaxies are rare, but astronomers believe that they were more common in the past, when the Universe was younger.

    “Atomic hydrogen gas is the fuel out of which new stars are formed, hence it is a crucial component to study if we are to understand how galaxies form and evolve,” study leader Dr Catinella said.

    “Because of the limitations of current instruments, astronomers still know very little about the gas content of galaxies beyond our local neighbourhood.”

    Local Group
    Local Group

    Co-author Dr Luca Cortese said detecting atomic hydrogen emission from distant galaxies is very challenging.

    “The signals are not only weak, but they appear at radio frequencies that are used by communication devices and radars, which generate signals billions of times stronger than the cosmic ones that we are trying to detect.”

    4
    Images of four distant galaxies observed with the Arecibo radio telescope, which have been found to host huge reservoirs of atomic hydrogen gas. Credit: Sloan Digital Sky Survey.Measuring the atomic hydrogen signal emitted by distant galaxies is one of the main scientific drivers behind the billion dollar Square Kilometre Array (SKA) project, for which technology demonstrators like the Australian SKA Pathfinder are under construction. The Arecibo observations give astronomers a glimpse into the population of gas-rich galaxies that will be routinely discovered by these instruments in coming decades.

    Sloan Digital Sky Survey Telescope
    Sloan Digital Sky Survey Telescope

    SKA Square Kilometer Array

    SKA Pathfinder Radio Telescope
    SKA Pathfinder Radio Telescope

    This project started as an experiment to see at what distances astronomers were able to detect the signal from atomic hydrogen in galaxies.

    “The outcome vastly exceeded our initial expectations,” Dr Catinella said.

    “Not only did we detect radio signals emitted by distant galaxies when the Universe was three billion years younger, but their gas reservoirs turned out to be unexpectedly large, about 10 times larger than the mass of hydrogen in our Milky Way. Such a huge amount of fuel will be able to feed star formation in these galaxies for several billion years in the future.”

    Further studies will seek to understand why these galaxies have not yet converted a great part of their gas into stars. The SKA and its pathfinders will be the key to solving this mystery.

    Further information

    The new results are published in B. Catinella & L. Cortese, HIGHz: A Survey of the Most HI-Massive Galaxies at z~0.2, Monthly Notices of the Royal Astronomical Society, in press, published by Oxford University Press (link will go live on 9 December 2014). A preprint is available on the arXiv.

    The research was supported under the Australian Research Council’s Future Fellowship and Discovery funding schemes.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.

     
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