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  • richardmitnick 2:41 pm on May 25, 2017 Permalink | Reply
    Tags: , Astrophysics, , , ,   

    NASA Ames: “NASA Selects New Research Teams to Further Solar System Exploration Research” 

    NASA Ames Icon

    March 17, 2017 [How did this slip by me?]
    Kimberly Williams
    Ames Research Center, Silicon Valley
    650-604-2457
    kimberly.k.williams@nasa.gov

    1
    No image caption or credit

    In an effort to advance basic and applied research for lunar and planetary science, and advance human exploration of the solar system through scientific discovery, NASA created the Solar System Exploration Research Virtual Institute or SSERVI. The institute fosters collaborations with science and exploration communities, which enables cross-disciplinary partnerships with research institutions, both domestic and abroad.

    NASA has selected four new research teams to join the existing nine teams in SSERVI to address scientific questions about the moon, near-Earth asteroids, the Martian moons Phobos and Deimos, and their near space environments, in cooperation with international partners.

    “We look forward to collaborative scientific discoveries from these teams,” said Jim Green, director of the Planetary Science Division of NASA’s Science Mission Directorate in Washington. “These results will be vital to NASA successfully conducting the ambitious activities of exploring the solar system with robots and humans.”

    SSERVI members include academic institutions, non-profit research institutes, private companies, NASA centers and other government laboratories. The new teams – which SSERVI will support for five years at a combined total of about $3-5 million per year – were selected from a pool of 22 proposals based on competitive peer-review evaluation.

    The selected SSERVI member teams, listed with their principal investigators and research topics, are:

    Network for Exploration and Space Science (NESS); Jack Burns, University of Colorado, Boulder, Colorado. NESS will implement cross-disciplinary partnerships to advance scientific discovery and human exploration at target destinations by conducting research in robotics, cosmology, astrophysics and heliophysics that is uniquely enabled by human and robotic exploration at the moon, near-Earth asteroids and comets, and Phobos and Deimos.

    Toolbox for Research and Exploration (TREX); Amanda Hendrix, Planetary Science Institute, Tucson, Arizona. TREX aims to develop tools and research methods for exploration of airless bodies, like the moon and asteroids, that are coated in fine-grained dust in order to prepare for human missions. Laboratory spectral measurements and experiments will accompany studies of existing datasets to understand surface characteristics and to investigate potential resources on airless bodies.

    Radiation Effects on Volatiles and Exploration of Asteroids and Lunar Surfaces (REVEALS); Thomas Orlando, Georgia Institute of Technology, Atlanta, Georgia. The REVEALS team will explore radiation processing of natural regolith and human-made composite materials to understand the condensed-matter physics and radiation chemistry that can lead to volatile formation, sequestration and transport. This team also will explore how novel materials and real-time radiation detectors can minimize risks and exposure to dangerous radiation during human exploration missions.

    Exploration Science Pathfinder Research for Enhancing Solar System Observations (ESPRESSO); Alex Parker, Southwest Research Institute, Boulder, Colorado. Team ESPRESSO will focus on characterizing target surfaces and mitigating hazards that create risk for robotic and human explorers. It will work to assess the geotechnical and thermomechanical properties of target body surfaces to help us understand and predict hazards like landslides, and to improve our understanding of impact ejecta dynamics.

    “We are extremely pleased that the community responded with such high-quality proposals, and look forward to the many contributions SSERVI will make in addressing NASA’s science and exploration goals,” said SSERVI Director Yvonne Pendleton.

    The SSERVI central office, located at NASA’s Ames Research Center in Silicon Valley, is funded by the agency’s Science Mission Directorate and Human Exploration and Operations Mission Directorate, and manages national and international collaborative partnerships, designed to push the boundaries of science and exploration.

    For more information about SSERVI and selected member teams, visit:

    http://sservi.nasa.gov

    See the full article here .

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    Ames Research Center, one of 10 NASA field Centers, is located in the heart of California’s Silicon Valley. For over 60 years, Ames has led NASA in conducting world-class research and development. With 2500 employees and an annual budget of $900 million, Ames provides NASA with advancements in:
    Entry systems: Safely delivering spacecraft to Earth & other celestial bodies
    Supercomputing: Enabling NASA’s advanced modeling and simulation
    NextGen air transportation: Transforming the way we fly
    Airborne science: Examining our own world & beyond from the sky
    Low-cost missions: Enabling high value science to low Earth orbit & the moon
    Biology & astrobiology: Understanding life on Earth — and in space
    Exoplanets: Finding worlds beyond our own
    Autonomy & robotics: Complementing humans in space
    Lunar science: Rediscovering our moon
    Human factors: Advancing human-technology interaction for NASA missions
    Wind tunnels: Testing on the ground before you take to the sky

    NASA image

     
  • richardmitnick 1:49 pm on May 25, 2017 Permalink | Reply
    Tags: , Astrophysics, , , , ,   

    From JPL-Caltech: “A Whole New Jupiter: First Science Results from NASA’s Juno Mission” 

    NASA JPL Banner

    JPL-Caltech

    May 25, 2017

    Dwayne Brown
    Headquarters, Washington
    202-358-1726
    dwayne.c.brown@nasa.gov

    Laurie Cantillo
    Headquarters, Washington
    202-358-1077
    laura.l.cantillo@nasa.gov

    DC Agle
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-393-9011
    agle@jpl.nasa.gov

    Nancy Neal Jones
    Goddard Space Flight Center, Greenbelt, Md.
    301-286-0039
    nancy.n.jones@nasa.gov

    Deb Schmid
    Southwest Research Institute, San Antonio
    210-522-2254
    dschmid@swri.org

    1
    This image shows Jupiter’s south pole, as seen by NASA’s Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection.
    Credits: NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles

    3
    An image of Jupiter taken by the Juno spacecraft. Credit: J.E.P. Connerney et al., Science (2017)phys.org

    3
    Credit: J.E.P. Connerney et al., Science (2017)phys.org

    Early science results from NASA’s Juno mission to Jupiter portray the largest planet in our solar system as a complex, gigantic, turbulent world, with Earth-sized polar cyclones, plunging storm systems that travel deep into the heart of the gas giant, and a mammoth, lumpy magnetic field that may indicate it was generated closer to the planet’s surface than previously thought.

    “We are excited to share these early discoveries, which help us better understand what makes Jupiter so fascinating,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. “It was a long trip to get to Jupiter, but these first results already demonstrate it was well worth the journey.”

    Juno launched on Aug. 5, 2011, entering Jupiter’s orbit on July 4, 2016. The findings from the first data-collection pass, which flew within about 2,600 miles (4,200 kilometers) of Jupiter’s swirling cloud tops on Aug. 27, are being published this week in two papers in the journal Science [http://science.sciencemag.org/cgi/doi/10.1126/science.aal2108] and [http://science.sciencemag.org/cgi/doi/10.1126/science.aam5928] , as well as 44 papers in Geophysical Research Letters [too many to chase down].

    “We knew, going in, that Jupiter would throw us some curves,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But now that we are here we are finding that Jupiter can throw the heat, as well as knuckleballs and sliders. There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”

    Among the findings that challenge assumptions are those provided by Juno’s imager, JunoCam. The images show both of Jupiter’s poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together.

    “We’re puzzled as to how they could be formed, how stable the configuration is, and why Jupiter’s north pole doesn’t look like the south pole,” said Bolton. “We’re questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we’re going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?”

    Another surprise comes from Juno’s Microwave Radiometer (MWR), which samples the thermal microwave radiation from Jupiter’s atmosphere, from the top of the ammonia clouds to deep within its atmosphere. The MWR data indicates that Jupiter’s iconic belts and zones are mysterious, with the belt near the equator penetrating all the way down, while the belts and zones at other latitudes seem to evolve to other structures. The data suggest the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred miles or kilometers.

    Prior to the Juno mission, it was known that Jupiter had the most intense magnetic field in the solar system. Measurements of the massive planet’s magnetosphere, from Juno’s magnetometer investigation (MAG), indicate that Jupiter’s magnetic field is even stronger than models expected, and more irregular in shape. MAG data indicates the magnetic field greatly exceeded expectations at 7.766 Gauss, about 10 times stronger than the strongest magnetic field found on Earth.

    “Juno is giving us a view of the magnetic field close to Jupiter that we’ve never had before,” said Jack Connerney, Juno deputy principal investigator and the lead for the mission’s magnetic field investigation at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Already we see that the magnetic field looks lumpy: it is stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action closer to the surface, above the layer of metallic hydrogen. Every flyby we execute gets us closer to determining where and how Jupiter’s dynamo works.”

    Juno also is designed to study the polar magnetosphere and the origin of Jupiter’s powerful auroras—its northern and southern lights. These auroral emissions are caused by particles that pick up energy, slamming into atmospheric molecules. Juno’s initial observations indicate that the process seems to work differently at Jupiter than at Earth.

    Juno is in a polar orbit around Jupiter, and the majority of each orbit is spent well away from the gas giant. But, once every 53 days, its trajectory approaches Jupiter from above its north pole, where it begins a two-hour transit (from pole to pole) flying north to south with its eight science instruments collecting data and its JunoCam public outreach camera snapping pictures. The download of six megabytes of data collected during the transit can take 1.5 days.

    “Every 53 days, we go screaming by Jupiter, get doused by a fire hose of Jovian science, and there is always something new,” said Bolton. “On our next flyby on July 11, we will fly directly over one of the most iconic features in the entire solar system — one that every school kid knows — Jupiter’s Great Red Spot. If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno and her cloud-piercing science instruments.”

    NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Juno mission for NASA. The principal investigator is Scott Bolton of the Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems, in Denver, built the spacecraft.

    More information on the Juno mission is available at:

    https://www.nasa.gov/juno

    http://missionjuno.org

    See the full article here .

    Please help promote STEM in your local schools.

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo

    NASA image

    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 1:15 pm on May 25, 2017 Permalink | Reply
    Tags: , Astrophysics, , , , , , , ,   

    From U Chicago: “World’s most sensitive dark matter detector releases first results” 

    U Chicago bloc

    University of Chicago

    May 18, 2017
    news@uchicago.edu
    (773) 702-8360
    News media only

    UChicago scientists part of international XENON collaboration

    1
    XENON1T installation in the underground hall of Laboratori Nazionali del Gran Sasso. The three story building on the right houses various auxiliary systems. The cryostat containing the LXeTPC is located inside the large water tank on the left. Photo by Roberto Corrieri and Patrick De Perio

    Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    2
    Scientists assembling the XENON1T time projection chamber. Photo by Enrico Sacchetti

    Scientists behind XENON1T, the largest dark matter experiment of its kind ever built, are encouraged by early results, describing them as the best so far in the search for dark matter.

    Dark matter is one of the basic constituents of the universe, five times more abundant than ordinary matter. Several astronomical measurements have corroborated the existence of dark matter, leading to an international effort to observe it directly. Scientists are trying to detect dark matter particle interacting with ordinary matter through the use of extremely sensitive detectors. Such interactions are so feeble that they have escaped direct detection to date, forcing scientists to build detectors that are more and more sensitive and have extremely low levels of radioactivity.

    On May 18, the XENON Collaboration released results from a first, 30-day run of XENON1T, showing the detector has a record low radioactivity level, many orders of magnitude below surrounding material on earth.

    “The care that we put into every single detail of the new detector is finally paying back,” said Luca Grandi, assistant professor in physics at the University of Chicago and member of the XENON Collaboration. “We have excellent discovery potential in the years to come because of the huge dimension of XENON1T and its incredibly low background. These early results already are allowing us to explore regions never explored before.”

    The XENON Collaboration consists of 135 researchers from the United States, Germany, Italy, Switzerland, Portugal, France, the Netherlands, Israel, Sweden and the United Arab Emirates, who hope to one day confirm dark matter’s existence and shed light on its mysterious properties.

    Located deep below a mountain in central Italy, XENON1T features a 3.2-ton xenon dual-phase time projection chamber. This central detector sits fully submersed in the middle of the water tank, in order to shield it from natural radioactivity in the cavern. A cryostat helps keep the xenon at a temperature of minus-95 degrees Celsius without freezing the surrounding water. The mountain above the laboratory further shields the detector, preventing it from being perturbed by cosmic rays.

    But shielding from the outer world is not enough, since all materials on Earth contain tiny traces of natural radioactivity. Thus extreme care was taken to find, select and process the materials making up the detector to achieve the lowest possible radioactive content. This allowed XENON1T to achieve record “silence” necessary to detect the very weak output of dark matter.

    A particle interaction in the one-ton central core of the time projection chamber leads to tiny flashes of light. Scientists record and study these flashes to infer the position and the energy of the interacting particle—and whether it might be dark matter.

    Despite the brief 30-day science run, the sensitivity of XENON1T has already overcome that of any other experiment in the field probing unexplored dark matter territory.

    “For the moment we do not see anything unexpected, so we set new constraints on dark matter properties,” Grandi said. “But XENON1T just started its exciting journey and since the end of the 30-day science run, we have been steadily accumulating new data.”

    UChicago central to international collaboration

    Grandi’s group is very active within XENON1T, and it is contributing to several aspects of the program. After its initial involvement in the preparation, assembly and early operations of the liquid xenon chamber, the group shifted its focus in the last several months to the development of the computing infrastructure and to data analysis.

    “Despite its low background, XENON1T is producing a large amount of data that needs to be continuously processed,” said Evan Shockley, a graduate student working with Grandi. “The raw data from the detector are directly transferred from Gran Sasso Laboratory to the University of Chicago, serving as the unique distribution point for the entire collaboration.”

    The framework, developed in collaboration with a group led by Robert Gardner, senior fellow at the Computation Institute, allows for the processing of data, both on local and remote resources belonging to the Open Science Grid. The involvement of UChicago’s Research Computing Center including Director Birali Runesha allows members of the collaboration all around the world to access processed data for high-level analyses.

    Grandi’s group also has been heavily involved in the analysis that led to this first result. Christopher Tunnell, a fellow at the Kavli Institute for Cosmological Physics, is one of the two XENON1T analysis coordinators and corresponding author of the result. Recently, UChicago hosted about 25 researchers for a month to perform the analyses that led to the first results.

    “It has been a large, concentrated effort and seeing XENON1T back on the front line makes me forget the never-ending days spent next to my colleagues to look at plots and distributions,“ Tunnell said. “There is no better thrill than leading the way in our knowledge of dark matter for the coming years.”

    See the full article here .

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    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 12:57 pm on May 25, 2017 Permalink | Reply
    Tags: , Astrophysics, , , , , N6946-BH1 is the only likely failed supernova that we found in the first seven years of our survey, , , NGC 6946 Fireworks Galaxy, SN 2017eaw   

    From Hubble: “Collapsing Star Gives Birth to a Black Hole” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    NASA/ESA Hubble Telescope

    May 25, 2017
    Christopher Kochanek / Krzysztof Stanek
    Ohio State University, Columbus, Ohio
    614-292-5954 / 614-292-3433
    kochanek.1@osu.edu / stanek.32@osu.edu

    Scott Adams
    Caltech, Pasadena, California
    626-395-8676
    smadams@caltech.edu

    Pam Frost Gorder
    Ohio State University, Columbus, Ohio
    614-292-9475
    gorder.1@osu.edu

    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, California
    818-354-6425
    elizabeth.r.landau@jpl.nasa.gov

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    1
    Massive Dying Star Goes Out With a Whimper Instead of a Bang

    Every second a star somewhere out in the universe explodes as a supernova. But some super-massive stars go out with a whimper instead of a bang. When they do, they can collapse under the crushing tug of gravity and vanish out of sight, only to leave behind a black hole. The doomed star, named N6946-BH1, was 25 times as massive as our sun. It began to brighten weakly in 2009. But, by 2015, it appeared to have winked out of existence. By a careful process of elimination, based on observations by the Large Binocular Telescope and the Hubble and Spitzer space telescopes, the researchers eventually concluded that the star must have become a black hole. This may be the fate for extremely massive stars in the universe.

    U Arizona Large Binocular Telescope, Mount Graham, Arizona, USA

    Astronomers have watched as a massive, dying star was likely reborn as a black hole. It took the combined power of the Large Binocular Telescope (LBT), and NASA’s Hubble and Spitzer space telescopes to go looking for remnants of the vanquished star, only to find that it disappeared out of sight.

    NASA/Spitzer Telescope

    It went out with a whimper instead of a bang.

    The star, which was 25 times as massive as our sun, should have exploded in a very bright supernova. Instead, it fizzled out—and then left behind a black hole.

    “Massive fails” like this one in a nearby galaxy could explain why astronomers rarely see supernovae from the most massive stars, said Christopher Kochanek, professor of astronomy at The Ohio State University and the Ohio Eminent Scholar in Observational Cosmology.

    As many as 30 percent of such stars, it seems, may quietly collapse into black holes — no supernova required.

    “The typical view is that a star can form a black hole only after it goes supernova,” Kochanek explained. “If a star can fall short of a supernova and still make a black hole, that would help to explain why we don’t see supernovae from the most massive stars.”

    He leads a team of astronomers who published their latest results in the Monthly Notices of the Royal Astronomical Society.

    Among the galaxies they’ve been watching is NGC 6946, a spiral galaxy 22 million light-years away that is nicknamed the “Fireworks Galaxy” because supernovae frequently happen there — indeed, SN 2017eaw, discovered on May 14th, is shining near maximum brightness now. Starting in 2009, one particular star, named N6946-BH1, began to brighten weakly. By 2015, it appeared to have winked out of existence.

    After the LBT survey for failed supernovas turned up the star, astronomers aimed the Hubble and Spitzer space telescopes to see if it was still there but merely dimmed. They also used Spitzer to search for any infrared radiation emanating from the spot. That would have been a sign that the star was still present, but perhaps just hidden behind a dust cloud.

    All the tests came up negative. The star was no longer there. By a careful process of elimination, the researchers eventually concluded that the star must have become a black hole.

    It’s too early in the project to know for sure how often stars experience massive fails, but Scott Adams, a former Ohio State student who recently earned his Ph.D. doing this work, was able to make a preliminary estimate.

    “N6946-BH1 is the only likely failed supernova that we found in the first seven years of our survey. During this period, six normal supernovae have occurred within the galaxies we’ve been monitoring, suggesting that 10 to 30 percent of massive stars die as failed supernovae,” he said.

    “This is just the fraction that would explain the very problem that motivated us to start the survey, that is, that there are fewer observed supernovae than should be occurring if all massive stars die that way.”

    To study co-author Krzysztof Stanek, the really interesting part of the discovery is the implications it holds for the origins of very massive black holes — the kind that the LIGO experiment detected via gravitational waves. (LIGO is the Laser Interferometer Gravitational-Wave Observatory.)


    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

    It doesn’t necessarily make sense, said Stanek, professor of astronomy at Ohio State, that a massive star could undergo a supernova — a process which entails blowing off much of its outer layers — and still have enough mass left over to form a massive black hole on the scale of those that LIGO detected.

    “I suspect it’s much easier to make a very massive black hole if there is no supernova,” he concluded.

    Adams is now an astrophysicist at Caltech. Other co-authors were Ohio State doctoral student Jill Gerke and University of Oklahoma astronomer Xinyu Dai. Their research was supported by the National Science Foundation.

    NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington, D.C. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

    The Large Binocular Telescope is an international collaboration among institutions in the United Sates, Italy and Germany.

    See the full article here .
    See the JPL-Caltech full article here .

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 11:17 am on May 25, 2017 Permalink | Reply
    Tags: , Astrophysics, , , Messier 87, , Weird energy beam seems to travel five times the speed of light   

    From New Scientist: “Weird energy beam seems to travel five times the speed of light” 

    NewScientist

    New Scientist

    22 May 2017
    Joshua Sokol

    1
    Trick of the light. NASA and The Hubble Heritage Team (STScI/AURA)

    Please welcome to the stage a master illusionist. An energy beam that stabs out of galaxy Messier 87 like a toothpick in a cocktail olive is pulling off the ultimate magic trick: seeming to move faster than the speed of light [always means speed of light in a vacuum].

    Almost five times faster, in fact, as measured by the Hubble Space Telescope.

    NASA/ESA Hubble Telescope

    This feat was first observed in 1995 in galaxy Messier 87, and has been seen in many other galaxies since. It might have you questioning your entire reality. Nothing can break the cosmic speed limit, right? You can’t just flaunt the laws of physics… can you?

    If you want to just enjoy the illusion from your seat in the audience, stop reading. Otherwise, I welcome you backstage for a look at how the trick works – and how it’s helping astronomers to understand the fate of entire galaxies.

    Blobs faster than light?

    We’ve known about the jet of plasma shooting from the core of Messier 87 since 1918, when astronomer Heber Curtis saw a ray of light connected to the galaxy. To be visible from so far away, it had to be huge – about 6000 light years long.

    As modern astronomers now know, pretty much all galaxies have a central black hole that periodically draws in stars and gas clouds.

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

    When gas begins to swirl down the drain, it heats up and magnetic fields focus some of it into jets of hot plasma. These jets shoot out at velocities near to – but not faster than – the speed of light.

    If you were to aim a telescope into the sky towards Messier 87, you would see that this lance of plasma is askew. Instead of pointing exactly into our line of sight, it’s angled a bit to the right.

    To understand the illusion, picture a single glowing blob of plasma starting at the base of this path and emitting a ray of light, both of which travel towards Earth. Now wait 10 years. In that time, the blob has moved closer at a sizeable fraction of the speed of light. That gives the rays emitted from that later position a few light years’ head start on the way to us.

    If you compare the first and second images from Earth’s perspective, it looks like the blob has just moved across the sky to the right. But because the second position is also closer to us, its light has had less far to travel than it appears. That means it seems to have arrived there faster than it actually did – as if the blob spent those 10 years travelling at ludicrous speed.

    One among many

    The jet from Messier 87 is more than just a curiosity, says Eileen Meyer at the University of Maryland, Baltimore County.

    All over the universe, outflows of energy from massive black holes can stop or start the formation of stars throughout galaxies. But it’s unclear how these outflows work and how much energy they contain.

    By appearing to move faster than light, jets such as the Messier 87 one change visibly over just a few years, which is unusual for distant objects like galaxies. That allows astronomers to make precise estimates of how fast the plasma is moving and thus how powerful the process is.

    Messier 87 is special because it is relatively close compared to other galaxies, making it easy to study. In 1999, astronomers used Hubble pictures of the jet taken over four years to see that plasma ripple outwards. In 2013, Meyer lengthened that to 13 years of images, which seemed to show that the plasma might also be moving in corkscrew-like spirals – as if it wasn’t complicated enough.

    Fresh results from Meyer, now being prepared for publication, extend that baseline again to a total of more than two decades and may offer new surprises. “Over 20 years, you know, things go bump in the night,” she says.

    And although the faster-than-light effect is old hat to her, she still stops to appreciate it sometimes. Most things we see travelling across the sky, such as planets and comets, are close to us. But Messier87 is tens of millions of light years away. “We can see, over a human lifetime, things moving,” she says. “Which is crazy.”

    See the full article here .

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  • richardmitnick 8:58 am on May 25, 2017 Permalink | Reply
    Tags: , , , Astrophysics, , ,   

    From Nautilus: “Opening a New Window into the Universe” 

    Nautilus

    Nautilus

    April 2017
    Andrea Ghez, UCLA, UCO

    7
    Andrea Ghez. PBS NOVA

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California

    Keck Observatory, Mauna Kea, Hawaii, USA

    New technology could bring new insights into the nature of black holes, dark matter, and extrasolar planets.

    Earthbound telescopes see stars and other astronomical objects through a haze. The light waves they gather have traveled unimpeded through space for billions of years, only to be distorted in the last millisecond by the Earth’s turbulent atmosphere. That distortion is now even more important, because scientists are preparing to build the three largest telescopes on Earth, each with light-gathering surfaces of 20 to 40 meters across.

    The new giant telescopes:

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile


    TMT-Thirty Meter Telescope, proposed for Mauna Kea, Hawaii, USA


    Giant Magellan Telescope, to be at Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile

    In principle, the larger the telescope, the higher the resolution of astronomical images. In practice, the distorting veil of the atmosphere has always limited what can be achieved. Now, a rapidly evolving technology known as adaptive optics can strip away the veil and enable astronomers to take full advantage of current and future large telescopes. Indeed, adaptive optics is already making possible important discoveries and observations, including: the discovery of the supermassive black hole at the center of our galaxy, proving that such exotic objects exist; the first images and spectra of planetary systems around other stars; and high-resolution observations of galaxies forming in the early universe.

    But adaptive optics has still not delivered its full scientific potential.

    ESO 4LGSF Adaptive Optics Facility (AOF)

    Existing technology can only partially correct the atmospheric blurring and cannot provide any correction for large portions of the sky or for the majority of the objects astronomers want to study.

    The project we propose here to fully exploit the potential of adaptive optics by taking the technology to the next level would boost research on a number of critical astrophysical questions, including:

    What are supermassive black holes and how do they work? Adaptive Optics has opened a new approach to studying supermassive black holes—through stellar orbits—but only the brightest stars, the tip of the iceberg, have been measured. With next generation adaptive optics we will be able to take the next leap forward in our studies of these poorly understood objects that are believed to play a central role in our universe. The space near the massive black hole at the center of our galaxy, for example, is a place where gravitational forces reach extreme levels. Does Einstein’s general theory of relativity still apply, or do exotic new physical phenomena emerge? How do these massive black holes shape their host galaxies? Early adaptive optics observations at the galactic center have revealed a completely unexpected environment, challenging our notions on the relationship between black holes and galaxies, which are a fundamental ingredient to cosmological models. One way to answer both of these questions is to find and measure the orbits of faint stars that are closer to the black hole than any known so far—which advanced adaptive optics would make possible.
    The first direct images of an extrasolar planet—obtained with adaptive optics—has raised fundamental questions about star and planet formation. How exactly do new stars form and then spawn planets from the gaseous disks around them? New, higher resolution images of this process—with undistorted data from larger telescopes—can help answer this question, and may also reveal how our solar system was formed. In addition, although only a handful of new-born planets has been found to date, advanced adaptive optics will enable astronomers to find many more and help determine their composition and life-bearing potential.
    Dark matter and dark energy are still completely mysterious, even though they constitute most of the universe.


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam

    But detailed observations using adaptive optics of how light from distant galaxies is refracted around a closer galaxy to form multiple images—so-called gravitational lensing—can help scientists understand how dark matter and dark energy change space itself.

    In addition, it is clear that telescopes endowed with advanced adaptive optics technology will inspire a whole generation of astronomers to design and carry out a multitude of innovative research projects that were previously not possible.

    4
    The laser system used to make artificial guide stars that sense the blurring effects of the Earth’s atmosphere being used on both Keck I and Keck II during adaptive optics observations of the center of our Galaxy. Next Generation Adaptive Optics would have multiple laser beams for each telescope. Ethan Tweedie

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

    The technology of adaptive optics is quite simple, in principle. First, astronomers measure the instantaneous turbulence in the atmosphere by looking at the light from a bright, known object—a “guide star”—or by using a laser tuned to make sodium atoms in a thin layer of the upper atmosphere fluoresce and glow as an artificial guide star.

    6
    ESO VLT Adaptive Optics new Guide Star laser light

    The turbulence measurements are used to compute (also instantaneously) the distortions that turbulence creates in the incoming light waves. Those distortions are then counteracted by rapidly morphing the surface of a deformable mirror in the telescope. Measurements and corrections are done hundreds of times per second—which is only possible with powerful computing capability, sophisticated opto-mechanical linkages, and a real-time control system. We know how to build these tools.

    Of course, telescopes that operate above the atmosphere, such as the Hubble Space Telescope, don’t need adaptive optics.

    NASA/ESA Hubble Telescope

    But both the Hubble and the coming next generation of space telescopes are small compared to the enormous earth-based telescopes now being planned.


    LSST Camera, built at SLAC



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

    And for the kinds of research that require very high resolution, such as the topics mentioned above and many others, there is really no substitute for the light-gathering power of telescopes too huge to be put into space.

    The next generation of adaptive optics could effectively take even the largest earth-bound telescopes “above the atmosphere” and make them truly amazing new windows on the universe. We know how to create this capability—the technology is in hand and the teams are assembled. It is time to put advanced adaptive optics to work.

    Creating Next Generation Adaptive Optics

    Adaptive optics (AO) imaging technology is used to improve the performance of optical systems by correcting distortions on light waves that have traveled through a turbulent medium. The technology has revolutionized fields from ophthalmology and vision science to laser communications. In astronomy, AO uses sophisticated, deformable mirrors controlled by fast computers to correct, in real-time, the distortion caused by the turbulence of the Earth’s atmosphere. Telescopes equipped with AO are already producing sharper, clearer views of distant astronomical objects than had ever before been possible, even from space. But current AO systems only partially correct for the effects of atmospheric blurring, and only when telescopes are pointed in certain directions. The aim of Next Generation Adaptive Optics is to overcome these limitations and provide precise correction for atmospheric blurring anywhere in the sky.

    One current limitation is the laser guide star that energizes sodium atoms in the upper atmosphere and causes them to glow as an artificial star used to measure the atmospheric distortions. This guide “star” is relatively close, only about 90 kilometers above the Earth’s surface, so the technique only probes a conical volume of the atmosphere above the telescope, and not the full cylinder of air through which genuine star light must pass to reach the telescope. Consequently, much of the distorting atmospheric structure is not measured. The next generation AO we propose will employ seven laser guide stars, providing full coverage of the entire cylindrical path travelled by light from the astronomical object being studied.

    6
    The next generation of adaptive optics will have several laser-created artificial guide stars, better optics, higher performance computers, and more advanced science instruments. Such a system will deliver the highest-definition images and spectra over nearly the entire sky and will enable unique new means of measuring the properties of stars, planets, galaxies, and black holes.
    J.Lu (U of Hawaii) & T. Do (UCLA)

    This technique can map the 3-D structure of the atmosphere, similar to how MRI medical imaging maps the human body. Simulations demonstrate that the resulting corrections will be excellent and stable, yielding revolutionary improvements in imaging. For example, the light from a star will be concentrated into a tiny area of the focal plane camera, and be far less spread out than it is with current systems, giving sharp, crisp images that show the finest detail possible.

    This will be particularly important for existing large telescopes such as the W. M. Keck Observatory (WMKO) [above]—currently the world’s leading AO platform in astronomy. Both our team—the UCLA Galactic Center Group (GCG)—and the WMKO staff have been deeply involved in the development of next generation AO systems.

    The quantum leap in the quality of both imaging and spectroscopy that next generation AO can bring to the Keck telescopes will likely pave the way for advanced AO systems on telescopes around the globe. For the next generation of extremely large telescopes, however, these AO advances will be critical. This is because the cylindrical volume of atmosphere through which light must pass to reach the mirrors in such large telescopes is so broad that present AO techniques will not be able to provide satisfactory corrections. For that reason, next generation AO techniques are critical to the future of infrared astronomy, and eventually of optical astronomy as well.

    The total proposed budget is $80 million over five years. The three major components necessary to take the leap in science capability include the laser guide star system, the adaptive optics system, and a powerful new science instrument, consisting of an infrared imager and an infrared spectrograph, that provides the observing capability to take advantage of the new adaptive optics system. This investment in adaptive optics will also help develop a strong workforce for other critical science and technology industries, as many students are actively recruited into industry positions in laser communications, bio-medical optics, big-data analytics for finance and business, image sensing and optics for government and defense applications, and the space industry. This investment will also help keep the U.S. in the scientific and technological lead. Well-funded European groups have recognized the power of AO and are developing competitive systems, though the next generation AO project described here will set an altogether new standard.

    Federal funding agencies find the science case for this work compelling, but they have made clear that it is beyond present budgetary means. Therefore, this is an extraordinary opportunity for private philanthropy—for visionaries outside the government to help bring this ambitious breakthrough project to reality and open a new window into the universe.

    Andrea Ghez is the Lauren B. Leichtman & Arthur E. Levine Chair in Astrophysics Director, UCLA Galactic Center Group.

    See the full article here .

    Please help promote STEM in your local schools.

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    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 8:25 am on May 25, 2017 Permalink | Reply
    Tags: , , Astrophysics, , , , ,   

    From Nautilus: “The Origin of the Universe” 

    Nautilus

    Nautilus

    April 2017
    John Carlstrom

    1
    The current South Pole telescope measuring small variations in the cosmic microwave background radiation that permeates the universe. Multiple telescopes with upgraded detectors could unlock additional secrets about the origins of the universe. Jason Gallicchio

    Measuring tiny variations in the cosmic microwave background will enable major discoveries about the origin of the universe.

    CMB per ESA/Planck


    ESA/Planck

    How is it possible to know in detail about things that happened nearly 14 billion years ago? The answer, remarkably, could come from new measurements of the cosmic microwave radiation that today permeates all space, but which was emitted shortly after the universe was formed.

    Previous measurements of the microwave background showed that the early universe was remarkably uniform, but not perfectly so: There are small variations in the intensity (or temperature) and polarization of the background radiation. These faint patterns show close agreement with predictions from what is now the standard theoretical model of how the universe began. That model describes an extremely energetic event—the Big Bang—followed within a tiny fraction of a second by a period of very accelerated expansion of the universe called cosmic inflation.

    4
    Alan Guth, Highland Park High School, NJ, USA and M.I.T., who first proposed cosmic inflation

    HPHS Owls

    Lambda-Cold Dark Matter, Accelerated Expansion of the Universe, Big Bang-Inflation (timeline of the universe) Date 2010 Credit: Alex MittelmannColdcreation

    5
    Alan Guth’s notes. http://www.bestchinanews.com/Explore/4730.html

    During this expansion, small quantum fluctuations were stretched to astrophysical scales, becoming the seeds that gave rise to the galaxies and other large-scale structures of the universe visible today.

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    After the cosmic inflation ended, the expansion began to slow and the primordial plasma of radiation and high-energy sub-atomic particles began to cool. Within a few hundred thousand years, the plasma had cooled sufficiently for atoms to form, for the universe to become transparent to light, and for the first light to be released. That first light has since been shifted—its wavelengths stretched 1,000-fold into the microwave spectrum by the continuing expansion of the universe—and is what we now measure as the microwave background [see above].

    Inflationary Universe. NASA/WMAP

    Recently the development of new superconducting detectors and more powerful telescopes are providing the tools to conduct an even more detailed study of the microwave background. And the payoff could be immense, including additional confirmation that cosmic inflation actually occurred, when it occurred, and how energetic it was, in addition to providing new insights into the quantum nature of gravity. Specifically the new research we propose can address a wide range of fundamental questions:

    1. The accelerated expansion of the universe in the first fraction of a second of its existence, as described by the inflation model, would have created a sea of gravitational waves. These distortions in spacetime would in turn would have left a distinct pattern in the polarization of the microwave background. Detecting that pattern would thus provide a key test of the inflation model, because the level of the polarization links directly to the time of inflation and its energy scale.
    2. Investigating the cosmic gravitational wave background would build on the stunning recent discovery of gravity waves, apparently from colliding black holes, helping to further the new field of gravitational wave astronomy.
    3. These investigations would provide a valuable window on physics at unimaginably high energy scales, a trillion times more energetic than the reach of the most powerful Earth-based accelerators.
    4. The cosmic microwave background provides a backlight on all structure in the universe. Its precise measurement will illuminate the evolution of the universe to the present day, allowing unprecedented insights and constraints on its still mysterious contents and the laws that govern them.

    The origin of the universe was a fantastic event. To gain an understanding of that beginning as an inconceivably small speck of spacetime and its subsequent evolution is central to unraveling continuing mysteries such as dark matter and dark energy. It can shed light on how the two great theories of general relativity and quantum mechanics relate to each other. And it can help us gain a clearer perspective on our human place within the universe. That is the opportunity that a new generation of telescopes and detectors can unlock.

    How to Measure Variations in the Microwave Background with Unparalleled Precision

    2
    Figure 1Ultra-sensitive superconducting bolometer detectors manufactured with thin-film techniques. The project proposes to deploy 500,000 such detectors. Chrystian Posada Arbelaez.

    The time for the next generation cosmic microwave background experiment is now. Transformational improvements have been made in both the sensitivity of microwave detectors and the ability to manufacture them in large numbers at low cost. The advance stems from the development of ultra-sensitive superconducting detectors called bolometers. These devices (Figure 1) essentially eliminate thermal noise by operating at a temperature close to absolute zero, but also are designed to make sophisticated use of electrothermal feedback—adjusting the current to the detectors when incoming radiation deposits energy, so as to keep the detector at its critical superconducting transition temperature under all operating conditions. The sensitivity of these detectors is limited only by the noise of the incoming signal—they generate an insignificant amount of noise of their own.

    Equally important are the production advances. These new ultra-sensitive detectors are manufactured with thin film techniques adapted from Silicon Valley—although using exotic superconducting materials—so that they can be rapidly and uniformly produced at greatly reduced cost. That’s important, because the proposed project needs to deploy about 500,000 detectors in all—something that would not be possible with hand-assembled devices as in the past. Moreover, the manufacturing techniques allow these sophisticated detectors to automatically filter the incoming signals for the desired wavelength sensitivity.

    3
    Figure 2The current focal plane on the South Pole Telescope with seven wafers of detectors plus hand-assembled individual detectors. A single detector wafer of the advanced design proposed here would provide more sensitivity and frequency coverage than this entire focal plane; the project would deploy several hundred such wafers across 10 or more telescopes. Jason Henning.

    To deploy the detectors, new telescopes are needed that have a wide enough focal plane to accommodate a large number of detectors—about 10,000 per telescope to capture enough incoming photons and see a wide enough area of the sky (Figure 2). They need to be placed at high altitude, exceedingly dry locations, so as to minimize the water vapor in the atmosphere that interferes with the incoming photons. The plan is to build on the two sites already established for ongoing background observations, the high Antarctic plateau at the geographic South Pole, and the high Atacama plateau in Chile. Discussions are underway with the Chinese about developing a site in Tibet; Greenland is also under consideration. In all, about 10 specialized telescopes will be needed, and will need to operate for roughly 5 years to accomplish the scientific goals described above. Equally important, the science teams that have come together to do this project will need significant upgrades to their fabrication and testing capabilities.

    The resources needed to accomplish this project are estimated at $100 million over 10 years, in addition to continuation of current federal funding. The technology is already proven and the upgrade path understood. Equally important, a cadre of young, enthusiastic, and well-trained scientists are eager to move forward. Unfortunately, constraints on the federal funding situation are already putting enormous stress on the ability of existing teams just to continue, and the expanded resources to accomplish the objectives described above are not available. This is thus an extraordinary opportunity for private philanthropy—an opportunity to “see” back in time to the very beginning of the universe and to understand the phenomena that shaped our world.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 1:22 pm on May 24, 2017 Permalink | Reply
    Tags: , , Astrophysics, , ,   

    From U Wisconsin IceCube: “IceCube sets new best limits for dark matter searches in neutrino detectors” 

    icecube
    U Wisconsin IceCube South Pole Neutrino Observatory

    24 May 2017
    Sílvia Bravo

    Studies aimed at understanding the nature and origin of dark matter include experiments in astronomy, astrophysics and particle physics. Astronomical observations point to the existence of dark matter in large amounts and in many cosmic environments, including the Milky Way. However, at the same time, the international quest to detect a dark matter interaction has so far been unsuccessful.

    IceCube has proven to be a champion detector for indirect searches of dark matter using neutrinos. As the amount of data grows and a better understanding of the detector allows making evermore precise measurements, the IceCube Collaboration continues exploring a vast range of dark matter energies and decay channels. In the most recent study, the collaboration sets the best limits on a neutrino signal from dark matter particles with masses between 10 and 100 GeV. These results have recently been submitted to the European Physical Journal C.

    2
    Comparison of upper limits on , i.e., the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles, versus WIMP mass, for dark matter self-annihilating through taus to neutrinos. The ‘natural scale’ refers to the value that is needed for WIMPs to be a thermal relic. Credit: IceCube Collaboration.

    Searches for dark matter usually focus on a generic candidate, called a weakly interacting massive particle, or WIMP. Physicists expect WIMPs to interact with other matter particles or to self-annihilate, producing a cascade of known particles, which for many channels and energies include neutrinos that can be detected on Earth. If this is the case, a neutrino detector on Earth is expected to detect an excess of neutrinos related to the distribution of dark matter in our galaxy. A similar signal is expected for photons.

    “The enormous size of IceCube allows the rare detection of high-energy neutrinos, but it is also essential for the detection of neutrinos at lower energies as it serves to identify incoming muons produced in cosmic ray air showers, which is a major challenge in searching for a signal from the Southern Hemisphere,” explains Morten Medici, a PhD student at the Niels Bohr Institute in Denmark and corresponding author of this study.

    See the full article here .

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    ICECUBE neutrino detector
    IceCube is a particle detector at the South Pole that records the interactions of a nearly massless sub-atomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter, and could reveal the new physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

     
  • richardmitnick 12:45 pm on May 24, 2017 Permalink | Reply
    Tags: , Astrophysics, , , , Enter the ‘Synestia’   

    From Centauri Dreams: “Enter the ‘Synestia’” 

    Centauri Dreams

    May 24, 2017
    Paul Gilster

    What happens when giant objects collide? We know the result will be catastrophic, as when we consider the possibility that the Moon was formed by a collision between the Earth and a Mars-sized object in the early days of the Solar System. But Sarah Stewart (UC-Davis) and Simon Lock (a graduate student at Harvard University) have produced a different possible outcome. Perhaps an impact between two infant planets would produce a single, disk-shaped object like a squashed doughnut, made up of vaporized rock and having no solid surface.

    Call it a ‘synestia,’ a coinage invoking the Greek goddess Hestia (goddess of the hearth, family, and domestic life, although the authors evidently drew on Hestia’s mythological connections to architecture). Stewart and Lock got interested in the possibility of such structures by asking about the effects of angular momentum, which would be conserved in any collision. Thus two giant bodies smashing into each other should result in the angular momentum of each being added together. Given enough energy (and there should be plenty), the hypothesized structure should form, an indented disk much larger than either planet.

    1
    Image: The structure of a planet, a planet with a disk and a synestia, all of the same mass. Credit: Simon Lock and Sarah Stewart

    The paper [ AGU Journal of Geophysical Resarch ] on this work notes that “…the structure of post-impact bodies influences the physical processes that control accretion, core formation and internal evolution. Synestias also lead to new mechanisms for satellite formation.” Moreover, Stewart and Lock believe that rocky planets are vaporized multiple times during their formation. Thus synestias should be a common outcome in young systems.

    See the full article here .

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    Tracking Research into Deep Space Exploration

    Alpha Centauri and other nearby stars seem impossible destinations not just for manned missions but even for robotic probes like Cassini or Galileo. Nonetheless, serious work on propulsion, communications, long-life electronics and spacecraft autonomy continues at NASA, ESA and many other venues, some in academia, some in private industry. The goal of reaching the stars is a distant one and the work remains low-key, but fascinating ideas continue to emerge. This site will track current research. I’ll also throw in the occasional musing about the literary and cultural implications of interstellar flight. Ultimately, the challenge may be as much philosophical as technological: to reassert the value of the long haul in a time of jittery short-term thinking.

     
  • richardmitnick 12:27 pm on May 24, 2017 Permalink | Reply
    Tags: , Astrophysics, , , Galaxy IC 342, NASA/DLR SOFIA   

    From SOFIA: “Understanding Star Formation in the Nucleus of Galaxy IC 342” 

    NASA SOFIA Banner

    NASA SOFIA

    SOFIA (Stratospheric Observatory For Infrared Astronomy)

    May 23, 2017
    Nicholas A. Veronico
    NVeronico@sofia.usra.edu
    SOFIA Science Center
    NASA Ames Research Center
    Moffett Field, California

    1
    A BIMA-SONG radio map of the IC 342 central molecular zone; dots indicate locations of SOFIA/GREAT observations.
    Credits: Röllig et al.

    An international team of researchers used NASA’s Stratospheric Observatory for Infrared Astronomy, SOFIA, to make maps of the ring of molecular clouds that encircles the nucleus of galaxy IC 342. The maps determined the proportion of hot gas surrounding young stars as well as cooler gas available for future star formation. The SOFIA maps indicate that most of the gas in the central zone of IC 342, like the gas in a similar region of our Milky Way Galaxy, is heated by already-formed stars, and relatively little is in dormant clouds of raw material.

    At a distance of about 13 million light years, galaxy IC 342 is considered relatively nearby. It is about the same size and type as our Milky Way Galaxy, and oriented face-on so we can see its entire disk in an undistorted perspective. Like our galaxy, IC 342 has a ring of dense molecular gas clouds surrounding its nucleus in which star formation is occurring. However, IC 342 is located behind dense interstellar dust clouds in the plane of the Milky Way, making it difficult to study by optical telescopes.

    The team of researchers from Germany and the Netherlands, led by Markus Röllig of the University of Cologne, Germany, used the German Receiver for Astronomy at Terahertz frequencies, GREAT, onboard SOFIA to scan the center of IC 342 at far-infrared wavelengths to penetrate the intervening dust clouds. Röllig’s group mapped the strengths of two far-infrared spectral lines – one line, at a wavelength of 158 microns, is emitted by ionized carbon, and the other, at 205 microns, is emitted by ionized nitrogen.

    The 158-micron line is produced both by cold interstellar gas that is the raw material for new stars, and also by hot gas illuminated by stars that have already finished forming. The 205-micron spectral line is only emitted by the hot gas around already-formed young stars. Comparison of the strengths of the two spectral lines allows researchers to determine of the amount of warm gas versus cool gas in the clouds.

    Röllig’s team found that most of the ionized gas in IC 342’s central molecular zone (CMZ) is in clouds heated by fully formed stars rather than in cooler gas found farther out in the zone, like the situation in the Milky Way’s CMZ. The team’s research was published in Astronomy and Astrophysics, volume 591.

    “SOFIA and its powerful GREAT instrument allowed us to map star formation in the center of IC 342 in unprecedented detail,” said Markus Röllig of the University of Cologne, Germany, “These measurements are not possible from ground-based telescopes or existing space telescopes.”

    Researchers previously used SOFIA’s GREAT spectrometer for a corresponding study of the Milky Way’s CMZ. That research, published in 2015 by principal investigator W.D. Langer, et. al, appeared in the journal Astronomy & Astrophysics 576, A1; an overview of that study can be found here.

    For more information about SOFIA, visit:

    http://www.nasa.gov/sofiahttp://www.dlr.de/en/sofia

    For information about SOFIA’s science mission and scientific instruments, visit:

    http://www.sofia.usra.eduhttp://www.dsi.uni-stuttgart.de/index.en.html

    See the full article here .

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    SOFIA is a joint project of NASA and the German Aerospace Center (DLR). The aircraft is based at and the program is managed from NASA Armstrong Flight Research Center’s facility in Palmdale, California. NASA’s Ames Research Center, manages the SOFIA science and mission operations in cooperation with the Universities Space Research Association (USRA) headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart.

    NASA image

    DLR Bloc

     
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