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  • richardmitnick 4:00 pm on November 18, 2014 Permalink | Reply
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    From LLNL: “Black hole loses its appetite for gassy cloud” 


    Lawrence Livermore National Laboratory

    Nov. 18, 2014

    Anne M Stark
    stark8@llnl.gov
    925-422-9799

    In a showdown of black hole versus G2 – a cloud of gas and dust – it looks like G2 won.

    g2
    This simulation shows the possible behavior of a gas cloud (G2) that has been observed approaching the black hole at the center of the Milky Way. Graphic by ESO/MPE/Marc Schartmann.

    Recent research shows that G2 came within 30 billion kilometers of the super-massive black hole at the center of our galaxy, yet managed to escape from the gravitational pull of the black hole.

    Initially, a supercomputer simulation prepared by two Lab physicists and a former postdoc more than two years ago suggested that some of G2 would survive, although its surviving mass would be torn apart, leaving it with a different shape and questionable fate.

    The findings are the work of computational physicist Peter Anninos and astrophysicist Stephen Murray, both of AX division within the Weapons and Complex Integration Directorate (WCI), along with their former postdoc Chris Fragile, now an associate professor at the College of Charleston in South Carolina, and his student, Julia Wilson.

    The team’s simulations allowed the members to more efficiently follow the cloud’s progression toward the black hole.

    But recent observations by an outside group show that G2 managed to escape the appetite of the black hole.

    “For it to have survived means that some gravity is keeping it intact,” Murray said. “The mass of the gas cloud by itself is far too small to hold the cloud together. If there were nothing else there, the cloud would have been torn apart, as indicated by our models and those of other researchers.”

    The black hole is known as Sagittarius A-star (Sgr A*). “Sgr” is the abbreviation for Sagittarius, the constellation in the direction of the center of the Milky Way. Most galaxies have a black hole at their center, some thousands of times bigger than this one, which has a mass of about 4 million times that of our sun.

    sgra*
    This image was taken with NASA’s Chandra X-Ray Observatory.
    10 January 2007

    sgr
    This Chandra image of Sgr A* and the surrounding region is based on data from a series of observations lasting a total of about one million seconds, or almost two weeks. Such a deep observation has given scientists an unprecedented view of the supernova remnant near Sgr A* (known as Sgr A East) and the lobes of hot gas extending for a dozen light years on either side of the black hole. These lobes provide evidence for powerful eruptions occurring several times over the last ten thousand years. The image also contains several mysterious X-ray filaments, some of which may be huge magnetic structures interacting with streams of energetic electrons produced by rapidly spinning neutron stars. Such features are known as pulsar wind nebulas.
    Date 7 January 2010

    NASA Chandra Telescope
    NASA Chandra schematic
    NASA/Chandra

    Astronomers originally noticed something in the region in 2002, but the first detailed determinations of G2’s size and orbit came in 2012. The dust in the cloud has been measured at about 550 degrees Kelvin, approximately twice as hot as the surface temperature on Earth. The gas, mostly hydrogen, is about 10,000 degrees Kelvin, or almost twice as hot as the surface of the sun.

    “A star being present within the cloud would make sense, and was suggested by earlier workers trying to explain the origin of the G2 cloud, which is otherwise pretty mysterious,” Murray said.

    One idea was that the cloud might be the result of an old star losing mass. Based on the brightness of the object, the mass of the star was estimated to be pretty small (no more than about the mass of our sun), and “our models indicated that it would be insufficient to hold the cloud together against the tidal forces of the black hole,” he said.

    However, in the new study (link is external) [link would not open] appearing in the journal Astrophysical Journal Letters, the researchers found that G2 is pretty much intact after its passage near the black hole. Some of the gas does show distortion by the gravity of the black hole, but there is a core of warm gas that has remained essentially unchanged. That would indicate something significantly more massive than our sun holding it together. The authors propose that it is the result of the merger of a close binary star system (two stars in orbit around each other). Such mergers might be due to interaction with the tidal field of the black hole, and the result might be a puffed-up star whose outer atmosphere is seen as the warm core of G2 that survived passage by the black hole.

    “That proposal means that we’re seeing G2 very shortly after the merger of the two stars,” Murray said. “While that’s certainly possible, it does mean that we’re seeing it at a special and relatively short-lived time. I haven’t seen strong arguments that the object can’t be a more typical star, somewhat more massive than our sun, undergoing normal mass loss as it nears the end of its life. Continued observations should let us determine just what’s inside of G2.”

    See the full article here.

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  • richardmitnick 4:05 pm on November 15, 2014 Permalink | Reply
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    From Chandra: “Sagittarius A*: NASA X-ray Telescopes Find Black Hole May Be a Neutrino Factory” 

    NASA Chandra

    November 13, 2014
    No Writer Credit

    Researchers have found evidence that the supermassive black hole at the center of the Milky Way may be generating neutrinos. Neutrinos are tiny particles that have virtually no mass and carry no electric charge. These particles are unusual because they can travel across the Universe without being absorbed or deflected. Scientists have long been looking for where neutrinos with high energies come from.

    sgra
    Credit NASA/CXC/Univ. of Wisconsin/Y.Bai. et al.
    Release Date November 13, 2014
    Observation Date 43 pointings from September 21, 1999 to May 18, 2009
    Observation Time 278 hours (11 days 14 hours).
    Instrument: ACIS
    Also Known As Galactic Center
    References Bai, et al, 2014, Physics Review D, 90, 063012; arXiv:1407.2243

    The supermassive black hole at the center of the Milky Way, seen in this image from NASA’s Chandra X-ray Observatory, may be producing mysterious particles called neutrinos, as described in our latest press release. Neutrinos are tiny particles that have virtually no mass and carry no electric charge. Unlike light or charged particles, neutrinos can emerge from deep within their sources and travel across the Universe without being absorbed by intervening matter or, in the case of charged particles, deflected by magnetic fields.

    While the Sun produces neutrinos that constantly bombard the Earth, there are also other neutrinos with much higher energies that are only rarely detected. Scientists have proposed that these higher-energy neutrinos are created in the most powerful events in the Universe like galaxy mergers, material falling onto supermassive black holes, and the winds around dense rotating stars called pulsars.

    Using three NASA X-ray telescopes, Chandra, Swift, and NuSTAR, scientists have found evidence for one such cosmic source for high-energy neutrinos: the 4-million-solar-mass black hole at the center of our Galaxy called Sagittarius A* (Sgr A*, for short). After comparing the arrival of high-energy neutrinos at the underground facility in Antarctica, called IceCube, with outbursts from Sgr A*, a team of researchers found a correlation. In particular, a high-energy neutrino was detected by IceCube less than three hours after astronomers witnessed the largest flare ever from Sgr A* using Chandra. Several flares from neutrino detections at IceCube also appeared within a few days of flares from the supermassive black hole that were observed with Swift and NuSTAR.

    NASA SWIFT Telescope
    NASA/Swift

    NASA NuSTAR
    NASA/Nu-STAR

    ICECUBE neutrino detector
    IceCube

    This Chandra image shows the region around Sgr A* in low, medium, and high-energy X-rays that have been colored red, green, and blue respectively. Sgr A* is located within the white area in the center of the image. The blue and orange plumes around that area may be the remains of outbursts from Sgr A* that occurred millions of years ago. The flares that are possibly associated with the IceCube neutrinos involve just the Sgr A* X-ray source.

    This latest result may also contribute to the understanding of another major puzzle in astrophysics: the source of high-energy cosmic rays. Since the charged particles that make up cosmic rays are deflected by magnetic fields in our Galaxy, scientists have been unable to pinpoint their origin. The charged particles accelerated by a shock wave near Sgr A* may be a significant source of very energetic cosmic rays.

    The paper describing these results was published in Physical Review D and is also available online. The authors of the study are Yang Bai, Amy Barger, Vernon Barger, R. Lu, Andrea Peterson, J. Salvado, all from the University of Wisconsin, in Madison, Wisconsin.

    See the full article here.

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    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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  • richardmitnick 12:25 pm on November 11, 2014 Permalink | Reply
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    From Chandra: A White Hole? 

    NASA Chandra

    Question of the Day! Could the supermassive black hole in Perseus be a supermassive “white” hole? In the Chandra X-ray image, the point is white, and in an X-ray photo, the white means that we can’t pass the object?

    white

    Answer: The object at the center of the X-ray image acts like a black hole, i.e. a very massive, very dense object that light cannot escape from. For example, the jets of material blown out by the object at the center of the galaxy should come from a black hole. Astronomers cannot think of any other object that can cause jets which are this large.

    The black hole shows up as a white dot because of the hot, dense gas spinning around a disk around the black hole. This hot gas glows in X-rays. We don’t see X-rays from the black hole itself, which would look black in this image, but is far too small to be detectable in this image.

    It is important to note that the X-rays and jets are not coming from the black hole itself, but from the surrounding matter, likely an accretion disk, in some way that we do not yet understand. 

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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  • richardmitnick 4:31 pm on October 29, 2014 Permalink | Reply
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    From Chandra: “NASA’S Chandra Observatory Identifies Impact of Cosmic Chaos on Star Birth” 

    NASA Chandra

    October 27, 2014

    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

    Janet Anderson
    Marshall Space Flight Center, Huntsville, Ala.
    256-544-6162
    janet.l.anderson@nasa.gov

    Megan Watzke
    Chandra X-ray Center, Cambridge, Mass.
    617-496-7998
    mwatzke@cfa.harvard.edu

    The same phenomenon that causes a bumpy airplane ride, turbulence, may be the solution to a long-standing mystery about stars’ birth, or the absence of it, according to a new study using data from NASA’s Chandra X-ray Observatory.

    Galaxy clusters are the largest objects in the universe, held together by gravity. These behemoths contain hundreds or thousands of individual galaxies that are immersed in gas with temperatures of millions of degrees.

    This hot gas, which is the heftiest component of the galaxy clusters aside from unseen dark matter, glows brightly in X-ray light detected by Chandra. Over time, the gas in the centers of these clusters should cool enough that stars form at prodigious rates. However, this is not what astronomers have observed in many galaxy clusters.

    “We knew that somehow the gas in clusters is being heated to prevent it cooling and forming stars. The question was exactly how,” said Irina Zhuravleva of Stanford University in Palo Alto, California, who led the study that appears in the latest online issue of the journal Nature. “We think we may have found evidence that the heat is channeled from turbulent motions, which we identify from signatures recorded in X-ray images.”

    Prior studies show supermassive black holes, centered in large galaxies in the middle of galaxy clusters, pump vast quantities of energy around them in powerful jets of energetic particles that create cavities in the hot gas. Chandra, and other X-ray telescopes, have detected these giant cavities before.

    The latest research by Zhuravleva and her colleagues provides new insight into how energy can be transferred from these cavities to the surrounding gas. The interaction of the cavities with the gas may be generating turbulence, or chaotic motion, which then disperses to keep the gas hot for billions of years.

    “Any gas motions from the turbulence will eventually decay, releasing their energy to the gas,” said co-author Eugene Churazov of the Max Planck Institute for Astrophysics in Munich, Germany. “But the gas won’t cool if turbulence is strong enough and generated often enough.”

    The evidence for turbulence comes from Chandra data on two enormous galaxy clusters named Perseus and Virgo. By analyzing extended observation data of each cluster, the team was able to measure fluctuations in the density of the gas. This information allowed them to estimate the amount of turbulence in the gas.

    tgwo
    Chandra observations of the Perseus and Virgo galaxy clusters suggest turbulence may be preventing hot gas there from cooling, addressing a long-standing question of galaxy clusters do not form large numbers of stars. Image Credit: NASA/CXC/Stanford/I. Zhuravleva et al

    “Our work gives us an estimate of how much turbulence is generated in these clusters,” said Alexander Schekochihin of the University of Oxford in the United Kingdom. “From what we’ve determined so far, there’s enough turbulence to balance the cooling of the gas.

    These results support the “feedback” model involving supermassive black holes in the centers of galaxy clusters. Gas cools and falls toward the black hole at an accelerating rate, causing the black hole to increase the output of its jets, which produce cavities and drive the turbulence in the gas. This turbulence eventually dissipates and heats the gas.

    While a merger between two galaxy clusters may also produce turbulence, the researchers think that outbursts from supermassive black holes are the main source of this cosmic commotion in the dense centers of many clusters.

    An interactive image, podcast, and video about these findings are available at:

    http://chandra.si.edu

    For more Chandra images, multimedia and related materials, visit:

    http://www.nasa.gov/chandra

    See the full article here.

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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  • richardmitnick 11:49 am on October 26, 2014 Permalink | Reply
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    From Chandra: “Chandra Archive Collection: Chandra’s Archives Come to Life” 

    NASA Chandra

    Six new images from Chandra’s vast archive are being released. Each of these images combines X-rays from Chandra with data from other telescopes. These images represent a tiny fraction of data that is now housed in Chandra’s archive over the mission’s 15 years of operation.

    six
    Composite

    xray
    X-rayCredit NASA/CXC/SAO
    Release Date October 21, 2014

    Every year, NASA’s Chandra X-ray Observatory looks at hundreds of objects throughout space to help expand our understanding of the Universe. Ultimately, these data are stored in the Chandra Data Archive, an electronic repository that provides access to these unique X-ray findings for anyone who would like to explore them. With the passing of Chandra’s 15th anniversary in operation on August 26, 1999, the archive continues to grow as each successive year adds to the enormous and invaluable dataset.

    To celebrate Chandra’s decade and a half in space, and to honor October as American Archives Month, a variety of objects have been selected from Chandra’s archive. Each of the new images we have produced combines Chandra data with those from other telescopes. This technique of creating “multiwavelength” images allows scientists and the public to see how X-rays fit with data of other types of light, such as optical, radio, and infrared. As scientists continue to make new discoveries with the telescope, the burgeoning archive will allow us to see the high-energy Universe as only Chandra can.

    ulPSR B1509-58 (upper left)
    Pareidolia is the psychological phenomenon where people see recognizable shapes in clouds, rock formations, or otherwise unrelated objects or data. When Chandra’s image ofPSR B1509-58, a spinning neutron star surrounded by a cloud of energetic particles, was released in 2009, it quickly gained attention because many saw a hand-like structure in the X-ray emission. In this new image of the system, X-rays from Chandra in gold are seen along with infrared data from NASA’s Wide-field Infrared Survey Explorer (WISE) telescope in red, green, and blue. Pareidolia may strike again in this image as some people report seeing a shape of a face in WISE’s infrared data.

    NASA Wise Telescope
    NASA/Wise

    urRCW 38 (upper right)
    A young star cluster about 5,500 light years from Earth, RCW 38 provides astronomers a chance to closely examine many young, rapidly evolving stars at once. In this composite image, X-rays from Chandra are blue, while infrared data from NASA’s Spitzer Space Telescope are orange and additional infrared data from the 2MASS survey appears white. There are many massive stars in RCW 38 that will likely explode as supernovas. Astronomers studying RCW 38 are hoping to better understand this environment as our Sun was likely born into a similar stellar nursery.

    NASA Spitzer Telescope
    NASA/Spitzer

    2MASS Telescope
    2MASS telescope interior
    Mt. Hopkins 2MASS 1.3-Meter telescope

    mlHercules A (middle left):
    Some galaxies have extremely bright cores, suggesting that they contain a supermassive black hole that is pulling in matter at a prodigious rate. Astronomers call these “active galaxies,” and Hercules A is one of them. In visible light (colored red, green and blue, with most objects appearing white), Hercules A looks like a typical elliptical galaxy. In X-ray light, however, Chandra detects a giant cloud of multimillion-degree gas (purple). This gas has been heated by energy generated by the infall of matter into a black hole at the center of Hercules A that is over 1,000 times as massive as the one in the middle of the Milky Way. Radio data (blue) show jets of particles streaming away from the black hole. The jets span a length of almost one million light years.

    mrKes 73 (middle right):
    The supernova remnant Kes 73, located about 28,000 light years away, contains a so-called anomalous X-ray pulsar, or AXP, at its center. Astronomers think that most AXPs are magnetars, which are neutron star with ultra-high magnetic fields. Surrounding the point-like AXP in the middle, Kes 73 has an expanding shell of debris from the supernova explosion that occurred between about 750 and 2100 years ago, as seen from Earth. The Chandra data (blue) reveal clumpy structures along one side of the remnant, and appear to overlap with infrared data (orange). The X-rays partially fill the shell seen in radio emission (red) by the Very Large Array. Data from the Digitized Sky Survey optical telescope (white) show stars in the field-of-view.

    NRAO VLA
    NRAO VLA

    llMrk 573 (lower left):
    Markarian 573 is an active galaxy that has two cones of emission streaming away from the supermassive black hole at its center. Several lines of evidence suggest that a torus, or doughnut of cool gas and dust may block some of the radiation produced by matter falling into supermassive black holes, depending on how the torus is oriented toward Earth. Chandra data of Markarian 573 suggest that its torus may not be completely solid, but rather may be clumpy. This composite image shows overlap between X-rays from Chandra (blue), radio emission from the VLA (purple), and optical data from Hubble (gold).

    NASA Hubble Telescope
    NASA/ESA Hubble

    4736
    NGC 4736 (also known as Messier 94) is a spiral galaxy that is unusual because it has two ring structures. This galaxy is classified as containing a “low ionization nuclear emission region,” or LINER, in its center, which produces radiation from specific elements such as oxygen and nitrogen. Chandra observations (gold) of NGC 4736, seen in this composite image with infrared data from Spitzer (red) and optical data from Hubble and the Sloan Digital Sky Survey (blue), suggest that the X-ray emission comes from a recent burst of star formation. Part of the evidence comes from the large number of point sources near the center of the galaxy, showing that strong star formation has occurred. In other galaxies, evidence points to supermassive black holes being responsible for LINER properties. Chandra’s result on NGC 4736 shows LINERs may represent more than one physical phenomenon.

    Sloan Digital Sky Survey Telescope
    Sloan Digital Sky Survey Telescope

    NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington, DC. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

    See the full article here.

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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  • richardmitnick 10:00 am on October 26, 2014 Permalink | Reply
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    From Science Daily: “Illusions in the cosmic clouds: New image of spinning neutron star” 

    ScienceDaily Icon

    Science Daily

    October 24, 2014
    Source: NASA/Jet Propulsion Laboratory

    Pareidolia is the psychological phenomenon where people see recognizable shapes in clouds, rock formations, or otherwise unrelated objects or data. There are many examples of this phenomenon on Earth and in space.

    When an image from NASA’s Chandra X-ray Observatory of PSR B1509-58 — a spinning neutron star surrounded by a cloud of energetic particles –was released in 2009, it quickly gained attention because many saw a hand-like structure in the X-ray emission.

    visions
    Do you see any recognizable shapes in this nebulous region captured by NASA’s WISE and Chandra missions?
    Credit: NASA/CXC/SAO: X-ray; NASA/JPL-Caltech: Infrared

    NASA Chandra Telescope
    NASA/Chandra

    In a new image of the system, X-rays from Chandra in gold are seen along with infrared data from NASA’s Wide-field Infrared Survey Explorer (WISE) telescope in red, green and blue. Pareidolia may strike again as some people report seeing a shape of a face in WISE’s infrared data. What do you see?

    NASA Wise Telescope
    NASA/Wise

    NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, also took a picture of the neutron star nebula in 2014, using higher-energy X-rays than Chandra.

    NASA NuSTAR
    NASA/ NuSTAR

    PSR B1509-58 is about 17,000 light-years from Earth.

    JPL, a division of the California Institute of Technology in Pasadena, manages the WISE mission for NASA. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

    More information is online at http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise.

    See the full article here.

    ScienceDaily is one of the Internet’s most popular science news web sites. Since starting in 1995, the award-winning site has earned the loyalty of students, researchers, healthcare professionals, government agencies, educators and the general public around the world. Now with more than 3 million monthly visitors, ScienceDaily generates nearly 15 million page views a month and is steadily growing in its global audience.

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  • richardmitnick 11:04 am on October 24, 2014 Permalink | Reply
    Tags: , , , , , NASA Chandra,   

    From CfA: “Accreting Supermassive Black Holes in the Early Universe” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    October 24, 2014
    No Writer Credit

    Supermassive black holes containing millions or even billions of solar-masses of material are found at the nuclei of galaxies. Our Milky Way, for example, has a nucleus with a black hole with about four million solar masses of material. Around the black hole, according to theories, is a torus of dust and gas, and when material falls toward the black hole (a process called accretion) the inner edge of the disk can be heated to millions of degrees. Such accretion heating can power dramatic phenomena like bipolar jets of rapidly moving charged particles. Such actively accreting supermassive black holes in galaxies are called active galactic nuclei (AGN).

    torus
    Torus

    The evolution of AGN in cosmic time provides a picture of their role in the formation and co-evolution of galaxies. Recently, for example, there has been some evidence that AGN with more modest luminosities and accretion rates (compared to the most dramatic cases) developed later in cosmic history (dubbed “downsizing”), although the reasons for and implications of this effect are debated. CfA astronomers Eleni Kalfontzou, Francesca Civano, Martin Elvis and Paul Green and a colleague have just published the largest study of X-ray selected AGN in the universe from the time when it was only 2.5 billion years old, with the most distant AGN in their sample dating from when the universe was about 1.2 billion years old.

    The astronomers studied 209 AGN detected with the Chandra X-ray Observatory.

    NASA Chandra Telescope
    NASA/Chandra

    image
    A multicolor image of galaxies in the field of the Chandra Cosmic Evolution Survey. A large, new study of 209 galaxies in the early universe with X-ray bright supermassive black holes finds that more modest AGN tend to peak later in cosmic history, and that obscured and unobscured AGN evolve in similar ways.
    X-ray: NASA/CXC/SAO/F.Civano et al. Optical: NASA/STScI

    They note that the X-ray observations are less contaminated by host galaxy emission than optical surveys, and consequently that they span a wider, more representative range of physical conditions. The team’s analysis confirms the proposed trend towards downsizing, while it also can effectively rule out some alternative proposals. The scientists also find, among other things, that this sample of AGN represents nuclei with a wide range of molecular gas and dust extinction. Combined with the range of AGN dates, this result enables them to conclude that obscured and unobscured phases of AGN evolve in similar ways.

    See the full article here.

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

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  • richardmitnick 6:18 pm on September 23, 2014 Permalink | Reply
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    From Chandra: “E0102-72.3: Adding a New Dimension to an Old Explosion” 2009 

    NASA Chandra

    July 23, 2009

    E0102 is the debris of a very massive star that exploded in the neighboring galaxy known as the Small Magellanic Cloud. Chandra first looked at this object nearly ten years ago, just months after the telescope was launched. Analysis of new Chandra data gives information on the geometry of the supernova explosion. The best model based on the data is that the ejecta is shaped like a cylinder that we see end-on.

    comp
    Composite

    xray
    X-ray

    opt
    Optical
    Credit X-ray (NASA/CXC/MIT/D.Dewey et al. & NASA/CXC/SAO/J.DePasquale); Optical (NASA/STScI)

    This image of the debris of an exploded star – known as supernova remnant 1E 0102.2-7219, or “E0102″ for short – features data from NASA’s Chandra X-ray Observatory. E0102 is located about 190,000 light years away in the Small Magellanic Cloud, one of the nearest galaxies to the Milky Way. It was created when a star that was much more massive than the Sun exploded, an event that would have been visible from the Southern Hemisphere of the Earth over 1000 years ago.

    smc
    The two-color image shows an overview of the full Small Magellanic Cloud (SMC) and was composed from two images from the Digitized Sky Survey 2. The field of view is slightly larger than 3.5 × 3.6 degrees. N66 with the open star cluster NGC 346 is the largest of the star-forming regions seen below the center of the SMC.

    Chandra first observed E0102 shortly after its launch in 1999. New X-ray data have now been used to create this spectacular image and help celebrate the ten-year anniversary of Chandra’s launch on July 23, 1999. In this latest image of E0102, the lowest-energy X-rays are colored orange, the intermediate range of X-rays is cyan, and the highest-energy X-rays Chandra detected are blue. An optical image from the Hubble Space Telescope (in red, green and blue) shows additional structure in the remnant and also reveals foreground stars in the field.

    NASA Hubble Telescope
    NASA/ESA Hubble

    The Chandra image shows the outer blast wave produced by the supernova (blue), and an inner ring of cooler (red-orange) material. This inner ring is probably expanding ejecta from the explosion that is being heated by a shock wave traveling backwards into the ejecta. A massive star (not visible in this image) is illuminating the green cloud of gas and dust to the lower right of the image. This star may have similar properties to the one that exploded to form E0102.

    Analysis of the Chandra spectrum gives astronomers new information about the geometry of the remnant, with implications for the nature of the explosion. The spectrum – which precisely separates X-rays of different energies – shows some material is moving away from Earth and some is moving toward us. When the material is moving away, its light is shifted toward the red end of the spectrum due to the so-called Doppler effect. Alternatively, when material is moving toward us, the light is bluer because of the same effect.

    A clear separation was detected between the red-shifted and blue-shifted light, leading astronomers to think that the appearance of E0102 is best explained by a model in which the ejecta is shaped like a cylinder that is being viewed almost exactly end-on. The smaller red and blue cylinders represent faster moving material closer to the cylinder axis.

    image

    This model suggests that the explosion that created the E0102 remnant may itself have been strongly asymmetric, consistent with the rapid kicks given to neutron stars after supernova explosions. Another possibility is that the star exploded into a disk of material formed when material was shed from the equator of the pre-supernova red giant star. Such asymmetries have been observed in winds from lower mass red giants that form planetary nebulas.

    See the full article, with video, here.

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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  • richardmitnick 8:15 pm on September 22, 2014 Permalink | Reply
    Tags: , , , NASA Chandra   

    From Chandra: “Vela Pulsar Jet: New Chandra Movie Features Neutron Star Action 

    NASA Chandra

    A new Chandra movie of the Vela pulsar shows it may be “precessing,” or wobbling as it spins. This movie contains 8 images from observations taken between June and September 2010. The Vela pulsar, found about 1,000 light years from Earth, formed when a massive star collapsed. The pulsar spins faster than a helicopter rotor and spews out a jet of particles at about 70% the speed of light.

    The included movie [see original post]from NASA’s Chandra X-ray Observatory shows a fast moving jet of particles produced by a rapidly rotating neutron star , and may provide new insight into the nature of some of the densest matter in the universe.

    The star of this movie is the Vela pulsar, a neutron star that was formed when a massive star collapsed. The Vela pulsar is about 1,000 light years from Earth, spans about 12 miles in diameter, and makes over 11 complete rotations every second, faster than a helicopter rotor. As the pulsar whips around, it spews out a jet of charged particles that race out along the pulsar’s rotation axis at about 70% of the speed of light. In this still image from the movie, the location of the pulsar and the 0.7-light-year-long jet are labeled.

    image
    Labeled Vela Pulsar Jet

    The Chandra data shown in the movie, containing 8 images obtained between June and September 2010, suggest that the pulsar may be slowly wobbling, or precessing, as it spins. The shape and the motion of the Vela jet look strikingly like a rotating helix, a shape that is naturally explained byprecession, as shown in this animation. If the evidence for precession of the Vela pulsar is confirmed, it would be the first time that a jet from a neutron star has been found to be precessing in this way.

    One possible cause of precession for a spinning neutron star is that it has become slightly distorted and is no longer a perfect sphere. This distortion might be caused by the combined action of the fast rotation and “glitches”, sudden increases of the pulsar’s rotational speed due to the interaction of the superfluid core of the neutron star with its crust.

    A paper describing these results [was] published in The Astrophysical Journal on January 10, 2013.

    This is the second Chandra movie of the Vela pulsar, with the original having been released in 2003. The first Vela movie contained shorter, unevenly spaced observations so that the changes in the jet were less pronounced and the authors did not argue that precession was occurring. However, based on the same data, Avinash Deshpande of Arecibo Observatory in Puerto Rico and the Raman Research Institute in Bangalore, India, and the late Venkatraman Radhakrishnan, argued in a 2007 paper that the Vela pulsar might be precessing.

    Arecibo Observatory
    Arecibo Observcatory

    The Earth also precesses as it spins, with a period of about 26,000 years. In the future Polaris will no longer be the “north star” and other stars will take its place. The period of the Vela precession is much shorter and is estimated to be about 120 days.

    wo
    Wide field Optical and X-ray
    Credit NASA/CXC/Univ of Toronto/M.Durant et al
    Release Date January 7, 2013

    The <a href=”http://en.wikipedia.org/wiki/Supernova”>supernova that formed the Vela pulsar exploded over 10,000 years ago. This optical image from the Anglo-Australian Observatory’s UK Schmidt telescope shows the enormous apparent size of the supernova remnant formed by the explosion. The full size of the remnant is about eight degrees across, or about 16 times the angular size of the moon. The square near the center shows the Chandra image with a larger field-of-view than used for the movie, with the Vela pulsar in the middle.

    Anglo Australian Telescope Exterior
    Anglo Australian Telescope Interior
    Anglo Australian Telescope

    See the full article,with video, here.

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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  • richardmitnick 12:00 pm on September 19, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From Chandra: “Tarantula Nebula (30 Doradus): A New View of the Tarantula Nebula” 2012 

    NASA Chandra

    April 17, 2012

    A new composite of 30 Doradus (aka, the Tarantula Nebula) contains data from Chandra (blue), Hubble (green), and Spitzer (red). 30 Doradus is one of the largest star-forming regions located close to the Milky Way. This region contains thousands of young massive stars, making it an excellent place to study how stars are born.

    NASA Hubble Telescope
    NASA/ESA Hubble

    NASA Spitzer Telescope
    NASA/Spitzer

    clomp
    Composite

    xray
    X-ray

    infra
    Infrared

    opt
    Optical
    Credit X-ray: NASA/CXC/PSU/L.Townsley et al.; Optical: NASA/STScI; Infrared: NASA/JPL/PSU/L.Townsley et al.
    Release Date April 17, 2012

    To celebrate its 22nd anniversary in orbit, the Hubble Space Telescope has released a dramatic new image of the star-forming region 30 Doradus, also known as the Tarantula Nebula because its glowing filaments resemble spider legs. A new image from all three of NASA’s Great Observatories – Chandra, Hubble, and Spitzer – has also been created to mark the event.

    30 Doradus is located in the neighboring galaxy called the Large Magellanic Cloud, and is one of the largest star-forming regions located close to the Milky Way . At the center of 30 Doradus, thousands of massive stars are blowing off material and producing intense radiation along with powerful winds. The Chandra X-ray Observatory detects gas that has been heated to millions of degrees by these stellar winds and also by supernova explosions. These X-rays, colored blue in this composite image, come from shock fronts — similar to sonic booms — formed by this high-energy stellar activity.

    lmc
    Large Magellanic Cloud

    The Hubble data in the composite image, colored green, reveals the light from these massive stars along with different stages of star birth including embryonic stars a few thousand years old still wrapped in cocoons of dark gas. Infrared emission from Spitzer, seen in red, shows cooler gas and dust that have giant bubbles carved into them. These bubbles are sculpted by the same searing radiation and strong winds that comes from the massive stars at the center of 30 Doradus.

    See the full article here.

    Another view:

    tr
    This first light image of the TRAPPIST national telescope at La Silla shows the Tarantula Nebula, located in the Large Magellanic Cloud (LMC) — one of the galaxies closest to us. Also known as 30 Doradus or NGC 2070, the nebula owes its name to the arrangement of bright patches that somewhat resembles the legs of a tarantula. Taking the name of one of the biggest spiders on Earth is very fitting in view of the gigantic proportions of this celestial nebula — it measures nearly 1000 light-years across! Its proximity, the favourable inclination of the LMC, and the absence of intervening dust make this nebula one of the best laboratories to help understand the formation of massive stars better. The image was made from data obtained through three filters (B, V and R) and the field of view is about 20 arcminutes across.
    8 June 2010

    ESO TRAPPIST telescope
    ESO Trappist Interior
    ESO/TRAPPIST Telescope

    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

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