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  • richardmitnick 10:02 pm on March 3, 2017 Permalink | Reply
    Tags: , , , , , IRAS 13224−3809, NASA NuSTAR,   

    From Astronomy: “This nearby supermassive black hole packs a pretty big punch” 

    Astronomy magazine

    Astronomy Magazine

    March 01, 2017
    Alison Klesman

    1
    NGC 6814 is a stunning example of a Seyfert galaxy. Like IRAS 13224−3809, this galaxy hosts a bright, highly X-ray variable supermassive black hole at its center. ESA/Hubble & NASA; Acknowledgement: Judy Schmidt (Geckzilla)

    Supermassive black holes are associated with the vast majority of galaxies. They’re believed to evolve with their host galaxies and even to affect galaxy growth over time, owing to their ability to gobble up vast amounts of gas and dust and shoot high-energy radiation back out into their surroundings.

    There are measurable correlations between the mass of a supermassive black hole and the properties of its host galaxy’s bulge, such as the luminosity of the bulge and the movements of stars within it. The reasons for these correlations are still unknown, but astronomers have long believed that supermassive black holes affect the star formation around them via some sort of feedback process.

    In a letter printed today in Nature, a group of astronomers led by Michael Parker at the Institute of Astronomy in Cambridge, UK, report their observations of IRAS 13224−3809, a nearby Seyfert galaxy hosting an active galactic nucleus, or AGN. Seyfert galaxies shine intensely in infrared light due to the activity of their supermassive black holes, which are relatively low mass but are accreting at high rates. IRAS 13224−3809 hosts a central supermassive black hole weighing about 6,000,000 times the mass of our Sun.

    Parker and his coauthors studied observations of IRAS 13224−3809 taken with the X-ray Multi-Mirror Mission [ESA/XMM-Newton] over the course of 17 days and with the Nuclear Spectroscopic Telescope Array [NASA/NuSTAR] over the course of six days. They observed X-ray variability on scales of minutes to weeks.

    ESA/XMM Newton
    ESA/XMM Newton

    NASA/NuSTAR
    NASA/NuSTAR

    By looking at the X-ray spectrum of the source, they were able to determine that this object offers a relatively unhindered view right down into the inner portions of the accretion disk near the black hole itself.

    When astronomers “look” at a supermassive black hole, they’re actually observing light from the accretion disk of matter around the black hole, which hasn’t yet fallen past the event horizon and become invisible. Supermassive black holes show variability over time in a variety of wavelengths, including optical light, infrared light, and X-rays. This variability is believed to arise from changes in the accretion disk, such as clumps of matter or outflows of gas and radiation.

    IRAS 13224−3809’s black hole shows extraordinary X-ray variability — in fact, it’s the most variable AGN observed at X-ray wavelengths. Parker’s group was able to watch the effects of an ultrafast outflow, which is associated with areas of the accretion disk within a few hundred times the size of the event horizon. Ultrafast outflows, or UFOs, are outflows moving faster than about 6,000 miles per second (10,000 km/s). They’re believed to be triggered by X-ray radiation associated with accretion at the innermost portions of the disk, just a few times the size of the event horizon.

    IRAS 13224−3809’s outflow was clocked at 44,000 miles per second (71,000 km/s), or about 0.236 times the speed of light. This puts it in the top 5 percent of UFOs ever observed. What’s more, the power it’s putting out is on par with quasars that are three orders of magnitude more massive.

    Because of their immense power, IRAS 13224−3809’s outflows may be strong enough to drive feedback in its host galaxy, just as more massive quasars do in the much more distant universe.

    While all black holes are variable, the timescale of variability typically scales with size. This makes sense when you think of variability relating to the accretion disk, which also scales with size. Thus, IRAS 13224−3809 shows much faster variability than the variability observed in quasars, which are similar but much more massive objects. Parker and his group were able to watch IRAS 13224−3809’s X-ray light undergo changes that took only hours, rather than months in a quasar.

    Studying IRAS 13224−3809 could thus help astronomers finally start to answer questions about how UFOs and other outflows are created. It could also shed light on how black hole feedback affects the host galaxy. This object’s unique properties would allow studies to be performed more easily and with much shorter observing times than those focused on faraway, slower-acting quasars.

    See the full article here .

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  • richardmitnick 2:19 pm on January 24, 2017 Permalink | Reply
    Tags: , , , , , NASA NuSTAR, Supernova SN 2014C   

    From JPL-Caltech: “NuSTAR Finds New Clues to ‘Chameleon Supernova'” 

    NASA JPL Banner

    JPL-Caltech

    January 24, 2017
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    Elizabeth.landau@jpl.nasa.gov

    1
    This visible-light image from the Sloan Digital Sky Survey shows spiral galaxy NGC 7331, center, where astronomers observed the unusual supernova SN 2014C .

    The inset images are from NASA’s Chandra X-ray Observatory, showing a small region of the galaxy before the supernova explosion (left) and after it (right). Red, green and blue colors are used for low, medium and high-energy X-rays, respectively.

    SDSS Telescope at Apache Point, NM, USA
    SDSS Telescope at Apache Point, NM, USA

    Fast Facts:

    — Supernova SN 2014C dramatically changed its appearance over a year

    — It appears SN 2014C threw off a lot of material before it exploded

    — The study suggests astronomers should pay attention to the lives of massive stars in the centuries before they explode

    “We’re made of star stuff,” astronomer Carl Sagan famously said. Nuclear reactions that happened in ancient stars generated much of the material that makes up our bodies, our planet and our solar system. When stars explode in violent deaths called supernovae, those newly formed elements escape and spread out in the universe.

    One supernova in particular is challenging astronomers’ models of how exploding stars distribute their elements. The supernova SN 2014C dramatically changed in appearance over the course of a year, apparently because it had thrown off a lot of material late in its life. This doesn’t fit into any recognized category of how a stellar explosion should happen. To explain it, scientists must reconsider established ideas about how massive stars live out their lives before exploding.

    “This ‘chameleon supernova’ may represent a new mechanism of how massive stars deliver elements created in their cores to the rest of the universe,” said Raffaella Margutti, assistant professor of physics and astronomy at Northwestern University in Evanston, Illinois. Margutti led a study about supernova SN 2014C published this week in The Astrophysical Journal.

    A supernova mystery

    Astronomers classify exploding stars based on whether or not hydrogen is present in the event. While stars begin their lives with hydrogen fusing into helium, large stars nearing a supernova death have run out of hydrogen as fuel. Supernovae in which very little hydrogen is present are called “Type I.” Those that do have an abundance of hydrogen, which are rarer, are called “Type II.”

    But SN 2014C, discovered in 2014 in a spiral galaxy about 36 million to 46 million light-years away, is different. By looking at it in optical wavelengths with various ground-based telescopes, astronomers concluded that SN 2014C had transformed itself from a Type I to a Type II supernova after its core collapsed, as reported in a 2015 study led by Dan Milisavljevic at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. Initial observations did not detect hydrogen, but, after about a year, it was clear that shock waves propagating from the explosion were hitting a shell of hydrogen-dominated material outside the star.

    In the new study, NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) satellite, with its unique ability to observe radiation in the hard X-ray energy range — the highest-energy X-rays — allowed scientists to watch how the temperature of electrons accelerated by the supernova shock changed over time. They used this measurement to estimate how fast the supernova expanded and how much material is in the external shell.

    NASA/NuSTAR
    NASA/NuSTAR

    To create this shell, SN 2014C did something truly mysterious: it threw off a lot of material — mostly hydrogen, but also heavier elements — decades to centuries before exploding. In fact, the star ejected the equivalent of the mass of the sun. Normally, stars do not throw off material so late in their life.

    “Expelling this material late in life is likely a way that stars give elements, which they produce during their lifetimes, back to their environment,” said Margutti, a member of Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics.

    NASA’s Chandra and Swift observatories were also used to further paint the picture of the evolution of the supernova.

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    NASA/SWIFT Telescope
    NASA/SWIFT Telescope

    The collection of observations showed that, surprisingly, the supernova brightened in X-rays after the initial explosion, demonstrating that there must be a shell of material, previously ejected by the star, that the shock waves had hit.

    Challenging existing theories

    Why would the star throw off so much hydrogen before exploding? One theory is that there is something missing in our understanding of the nuclear reactions that occur in the cores of massive, supernova-prone stars. Another possibility is that the star did not die alone — a companion star in a binary system may have influenced the life and unusual death of the progenitor of SN 2014C. This second theory fits with the observation that about seven out of 10 massive stars have companions.

    The study suggests that astronomers should pay attention to the lives of massive stars in the centuries before they explode. Astronomers will also continue monitoring the aftermath of this perplexing supernova.

    “The notion that a star could expel such a huge amount of matter in a short interval is completely new,” said Fiona Harrison, NuSTAR principal investigator based at Caltech in Pasadena. “It is challenging our fundamental ideas about how massive stars evolve, and eventually explode, distributing the chemical elements necessary for life.”

    NuSTAR is a Small Explorer mission led by Caltech and managed by JPL for NASA’s Science Mission Directorate in Washington. NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp., Dulles, Virginia. NuSTAR’s mission operations center is at UC Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center. ASI provides the mission’s ground station and a mirror archive. JPL is managed by Caltech for NASA.

    For more information on NuSTAR, visit:

    http://www.nasa.gov/nustar

    http://www.nustar.caltech.edu

    See the full article here .

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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.

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  • richardmitnick 12:56 pm on January 12, 2017 Permalink | Reply
    Tags: , , IC 3639, Monster black holes, , NASA NuSTAR, NGC 1448, , , Type II supernova   

    From Space Science Laboratory at UC Berkeley: “NuSTAR – Black Holes Hide in our Cosmic Backyard” 

    UC Berkeley

    UC Berkeley

    SSL UC Berkeley

    Space Science Laboratory

    1
    No image caption. No image credit.

    NASA/NuSTAR

    NuSTAR

    January 12, 2017
    Christopher Scholz

    Monster black holes sometimes lurk behind gas and dust, hiding from the gaze of most telescopes. But they give themselves away when material they feed on emits high-energy X-rays that NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) mission can detect. That’s how NuSTAR recently identified two gas-enshrouded supermassive black holes, located at the centers of nearby galaxies.

    “These black holes are relatively close to the Milky Way, but they have remained hidden from us until now,” said Ady Annuar, a graduate student at Durham University in the United Kingdom, who presented the results at the American Astronomical Society meeting in Grapevine, Texas. “They’re like monsters hiding under your bed.”

    Both of these black holes are the central engines of what astronomers call “active galactic nuclei,” a class of extremely bright objects that includes quasars and blazars. Depending on how these galactic nuclei are oriented and what sort of material surrounds them, they appear very different when examined with telescopes.

    Active galactic nuclei are so bright because particles in the regions around the black hole get very hot and emit radiation across the full electromagnetic spectrum — from low-energy radio waves to high-energy X-rays. However, most active nuclei are believed to be surrounded by a doughnut-shaped region of thick gas and dust that obscures the central regions from certain lines of sight. Both of the active galactic nuclei that NuSTAR recently studied appear to be oriented such that astronomers view them edge-on. That means that instead of seeing the bright central regions, our telescopes primarily see the reflected X-rays from the doughnut-shaped obscuring material.

    “Just as we can’t see the sun on a cloudy day, we can’t directly see how bright these active galactic nuclei really are because of all of the gas and dust surrounding the central engine,” said Peter Boorman, a graduate student at the University of Southampton in the United Kingdom.

    Boorman led the study of an active galaxy called IC 3639, which is 170 million light years away.

    2
    IC 3639, a galaxy with an active galactic nucleus, is seen in this image combining data from the Hubble Space Telescope and the European Southern Observatory.

    This galaxy contains an example of a supermassive black hole hidden by gas and dust. Researchers analyzed NuSTAR data from this object and compared them with previous observations from NASA’s Chandra X-Ray Observatory and the Japanese-led Suzaku satellite.

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    JAXA/Suzaku satellite
    JAXA/Suzaku satellite

    The findings from NuSTAR, which is more sensitive to higher energy X-rays than these observatories, confirm the nature of IC 3639 as an active galactic nucleus that is heavily obscured, and intrinsically much brighter than observed.

    Researchers analyzed NuSTAR data from this object and compared them with previous observations from NASA’s Chandra X-Ray Observatory and the Japan-led Suzaku satellite. NuSTAR also provided the first precise measurement of how much material is obscuring the central engine of IC 3639, allowing researchers to determine how luminous this hidden monster really is.

    More surprising is the spiral galaxy that Annuar focused on: NGC 1448.

    6
    NGC 1448 (also designated NGC 1457 and ESO 249-16) is a spiral galaxy located about 60 million light-years away in the constellation Horologium. It has a prominent disk of young and very bright stars surrounding its small, shining core. The galaxy is receding from us with 1168 kilometers per second.

    NGC 1448 has recently been a prolific factory of supernovae, the dramatic explosions that mark the death of stars: after a first one observed in this galaxy in 1983 (SN 1983S), two more have been discovered during the past decade.

    Visible as a red dot inside the disc, in the upper right part of the image, is the supernova observed in 2003 (Type II supernova SN 2003hn), whereas another one, detected in 2001 (Type Ia supernova SN 2001el), can be noticed as a tiny blue dot in the central part of the image, just below the galaxy’s core. If captured at the peak of the explosion, a supernova might be as bright as the whole galaxy that hosts it.

    A Type Ia supernova is a result from the violent explosion of a white dwarf star. This category of supernovae produces consistent peak luminosity. The stability of this luminosity allows these supernovae to be used as standard candles to measure the distance to their host galaxies because the visual magnitude of the supernovae depends primarily on the distance.

    A Type II supernova results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, and no more than 40–50 times the mass of the Sun for this type of explosion. It is distinguished from other types of supernova by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.

    This image was obtained using the 8.2-metre telescopes of ESO’s Very Large Telescope. It combines exposures taken between July 2002 and the end of November 2003.

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

    Credit: ESO

    The black hole in its center was only discovered in 2009, even though it is at the center of one of the nearest large galaxies to our Milky Way. By “near,” astronomers mean NGC 1448 is only 38 million light years away (one light year is about 6 trillion miles).

    Annuar’s study discovered that this galaxy also has a thick column of gas hiding the central black hole, which could be part of a doughnut-shaped region. X-ray emission from NGC 1448, as seen by NuSTAR and Chandra, suggests for the first time that, as with IC 3639, there must be a thick layer of gas and dust hiding the active black hole in this galaxy from our line of sight.

    Researchers also found that NGC 1448 has a large population of young (just 5 million year old) stars, suggesting that the galaxy produces new stars at the same time that its black hole feeds on gas and dust. Researchers used the European Southern Observatory New Technology Telescope to image NGC 1448 at optical wavelengths, and identified where exactly in the galaxy the black hole should be. A black hole’s location can be hard to pinpoint because the centers of galaxies are crowded with stars. Large optical and radio telescopes can help detect light from around black holes so that astronomers can find their location and piece together the story of their growth.

    “It is exciting to use the power of NuSTAR to get important, unique information on these beasts, even in our cosmic backyard where they can be studied in detail,” said Daniel Stern, NuSTAR project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California.

    NuSTAR is a Small Explorer mission led by Caltech and managed by JPL for NASA’s Science Mission Directorate in Washington. NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp., Dulles, Virginia. NuSTAR’s mission operations center is at UC Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center. ASI provides the mission’s ground station and a mirror archive. JPL is managed by Caltech for NASA.

    See the full article here .

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  • richardmitnick 11:39 am on July 29, 2016 Permalink | Reply
    Tags: , , , NASA NuSTAR   

    From AAS NOVA: “Observing the Sun with NuSTAR” 

    AASNOVA

    American Astronomical Society

    29 July 2016
    Susanna Kohler

    1
    A composite image of the Sun showing high-energy X-rays from NuSTAR (blue), low-energy X-rays from Japan’s Hinode spacecraft (green), and extreme ultraviolet light from the Solar Dynamics Observatory (yellow and red). [NASA/JPL-Caltech/GSFC/JAXA]

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is a space telescope primarily designed to detect high-energy X-rays from faint, distant astrophysical sources.

    NASA/NuSTAR
    NASA/NuSTAR

    JAXA/HINODE spacecraft
    JAXA/HINODE spacecraft

    Recently, however, it’s occasionally been pointing much closer to home, with the goal of solving a few longstanding mysteries about the Sun.

    2
    Intensity maps from an observation of a quiet-Sun region near the north solar pole and an active region just below the solar limb. The quiet-Sun data will be searched for small flares that could be heating the solar corona, and the high-altitude emission above the limb may provide clues about particle acceleration. [Adapted from Grefenstette et al. 2016]

    An Unexpected Target

    Though we have a small fleet of space telescopes designed to observe the Sun, there’s an important gap: until recently, there was no focusing telescope making solar observations in the hard X-ray band (above ~3 keV). Conveniently, there is a tool capable of doing this: NuSTAR.

    Though NuSTAR’s primary mission is to observe faint astrophysical X-ray sources, a team of scientists has recently conducted a series of observations in which NuSTAR was temporarily repurposed and turned to focus on the Sun instead.

    These observations pose an interesting challenge precisely because of NuSTAR’s extreme sensitivity: pointing at such a nearby, bright source can quickly swamp the detectors. But though the instrument can’t be used to observe the bright flares and outbursts from the Sun, it’s the perfect tool for examining the parts of the Sun we’ve been unable to explore in hard X-rays before now — such as faint flares, or the quiet, inactive solar surface.

    In a recently published study led by Brian Grefenstette (California Institute of Technology), the team describes the purpose and initial results of NuSTAR’s first observations of the Sun.

    Solar Mysteries

    What is NuSTAR hoping to accomplish with its solar observations? There are two main questions that hard X-ray observations may help to answer.

    How are particles accelerated in solar flares?
    The process of electron acceleration during solar flares is not well understood. When a flare-producing active region is occulted by the solar limb, NuSTAR will able to directly observe the flare loop above the solar surface — which is where that acceleration is thought to happen.
    How is the solar corona heated?
    The solar corona is a toasty 1–3 million Kelvin — significantly warmer than the ~6000 K solar photosphere. So how is the corona heated? One proposed explanation is that the Sun’s surface constantly emits tiny nanoflares — in active regions, or even in the quiet Sun — that are so faint that we haven’t detected them. But with its high sensitivity, NuSTAR may be able to!

    4
    The first NuSTAR full-disk mosaic of the Sun. The checkerboard pattern is an artifact of the detectors being hit by particles from active regions outside of the field of view — a problem which will be reduced as the Sun enters the upcoming quieter part of the solar cycle. [Adapted from Grefenstette et al. 2016]

    First Observations

    In NuSTAR’s first four observations of the Sun, the team unexpectedly observed a major flare (which unsurprisingly swamped the detectors), watched the emission above an active region that was hidden by the solar limb, stared at a section of quiet Sun near the north solar pole, and composed a full-disk mosaic of the solar surface from 16 12’ x 12’ tiles.

    All of these initial observations are currently being carefully analyzed and will be presented in detail in future publications. In the meantime, NuSTAR has demonstrated its effectiveness in detecting faint emission in solar hard X-rays, proving that it will be a powerful tool for heliophysics as well as for astrophysics. We look forward to seeing the future results from this campaign!
    Citation

    Brian W. Grefenstette et al 2016 ApJ 826 20. doi:10.3847/0004-637X/826/1/20

    See the full article here .

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  • richardmitnick 1:53 pm on January 5, 2016 Permalink | Reply
    Tags: , , , NASA NuSTAR   

    From NASA NuSTAR: “Andromeda Galaxy Scanned with High-Energy X-ray Vision” 

    NASA NuSTAR
    NuSTAR

    1

    January 5, 2016
    No writer credit found

    NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, has captured the best high-energy X-ray view yet of a portion of our nearest large, neighboring galaxy, Andromeda. The space mission has observed 40 X-ray binaries — intense sources of X-rays comprised of a black hole or neutron star that feeds off a stellar companion.

    The results will ultimately help researchers better understand the role of X-ray binaries in the evolution of our universe. According to astronomers, these energetic objects may play a critical role in heating the intergalactic bath of gas in which the very first galaxies formed.

    “Andromeda is the only large spiral galaxy where we can see individual X-ray binaries and study them in detail in an environment like our own,” said Daniel Wik of NASA Goddard Space Flight Center in Greenbelt, Maryland, who presented the results at the 227th meeting of American Astronomical Society in Kissimmee, Florida. “We can then use this information to deduce what’s going on in more distant galaxies, which are harder to see.”

    Andromeda, also known as M31, can be thought of as the big sister to our own Milky Way galaxy. Both galaxies are spiral in shape, but Andromeda is slightly larger than the Milky Way in size. Lying 2.5 million light-years away, Andromeda is relatively nearby in cosmic terms. It can even be seen by the naked eye in dark, clear skies. [It is not mentioned here, but Andromeda and the Milky Way are apparently destined to merge in the distant future.]

    Other space missions, such as NASA’s Chandra X-ray Observatory, have obtained crisper images of Andromeda at lower X-ray energies than the high-energy X-rays detected by NuSTAR.

    NASA Chandra Telescope
    NASA/Chandra

    The combination of Chandra and NuSTAR provides astronomers with a powerful tool for narrowing in on the nature of the X-ray binaries in spiral galaxies.

    In X-ray binaries, one member is always a dead star or remnant formed from the explosion of what was once a star much more massive than the sun. Depending on the mass and other properties of the original giant star, the explosion may produce either a black hole or neutron star. Under the right circumstances, material from the companion star can “spill over” its outermost edges and then be caught by the gravity of the black hole or neutron star. As the material falls in, it is heated to blazingly high temperatures, releasing a huge amount of X-rays.

    With NuSTAR’s new view of a swath of Andromeda, Wik and colleagues are working on identifying the fraction of X-ray binaries harboring black holes versus neutron stars. That research will help them understand the population as a whole.

    “We have come to realize in the past few years that it is likely the lower-mass remnants of normal stellar evolution, the black holes and neutron stars, may play a crucial role in heating of the intergalactic gas at very early times in the universe, around the cosmic dawn,” said Ann Hornschemeier of NASA Goddard, the principal investigator of the NuSTAR Andromeda studies.

    “Observations of local populations of stellar-mass-sized black holes and neutron stars with NuSTAR allow us to figure out just how much power is coming out from these systems.”

    The new research also reveals how Andromeda may differ from our Milky Way. Fiona Harrison, the principal investigator of the NuSTAR mission, added, “Studying the extreme stellar populations in Andromeda tells us about how its history of forming stars may be different than in our neighborhood.”

    Harrison will be presenting the 2015 Rossi Prize lecture at the AAS meeting. The prize, awarded by the AAS’s High-Energy Astrophysics Division, honors physicist Bruno Rossi, an authority on cosmic-ray physics and a pioneer in the field of X-ray astronomy.

    See the full article here .

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    NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by NASA’s Jet Propulsion Laboratory, also in Pasadena, for NASA’s Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley ; Columbia University, New York; NASA’s Goddard Space Flight Center, Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, Calif.; ATK Aerospace Systems, Goleta, Calif., and with support from the Italian Space Agency (ASI) Science Data Center.

    NuSTAR’s mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located at Malindi, Kenya. The mission’s outreach program is based at Sonoma State University, Rohnert Park, Calif. NASA’s Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

    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.

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  • richardmitnick 8:33 pm on December 17, 2015 Permalink | Reply
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    From JPL-Caltech: “NuSTAR Finds Cosmic Clumpy Doughnut Around Black Hole” 

    JPL-Caltech

    December 17, 2015
    Whitney Clavin
    Jet Propulsion Laboratory, Pasadena, California
    818-354-4673
    whitney.clavin@jpl.nasa.gov

    1
    Galaxy NGC 1068 can be seen in close-up in this view from NASA’s Hubble Space Telescope.

    NASA Hubble Telescope
    NASA/ESA Hubble

    NuSTAR’s high-energy X-rays eyes were able to obtain the best view yet into the hidden lair of the galaxy’s central, supermassive black hole.

    NASA NuSTAR
    NASA/NuSTAR

    2
    This active black hole is one of the most obscured known, meaning that it is surrounded by extremely thick clouds of gas and dust.

    The NuSTAR data revealed that the torus of gas and dust surrounding the black hole, also referred to as a doughnut, is more clumpy than previously thought. doughnuts around active, supermassive black holes were originally proposed in the mid-1980s to be smooth entities. More recently, researchers have been finding that doughnuts are not so smooth but have lumps. NuSTAR’s latest finding shows that this is true for even the thickest of doughnuts.

    NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by NASA’s Jet Propulsion Laboratory, also in Pasadena, for NASA’s Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Virginia. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA’s Goddard Space Flight Center, Greenbelt, Maryland; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, California; ATK Aerospace Systems, Goleta, California, and with support from the Italian Space Agency (ASI) Science Data Center.

    NuSTAR’s mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located at Malindi, Kenya. The mission’s outreach program is based at Sonoma State University, Rohnert Park, California. NASA’s Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

    For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/.

    The most massive black holes in the universe are often encircled by thick, doughnut-shaped disks of gas and dust. This deep-space doughnut material ultimately feeds and nourishes the growing black holes tucked inside.

    Until recently, telescopes weren’t able to penetrate some of these doughnuts, also known as tori.

    “Originally, we thought that some black holes were hidden behind walls or screens of material that could not be seen through,” said Andrea Marinucci of the Roma Tre University in Italy, lead author of a new Monthly Notices of the Royal Astronomical Society study describing results from NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, and the European Space Agency’s XMM-Newton space observatory.

    With its X-ray vision, NuSTAR recently peered inside one of the densest of these doughnuts known to surround a supermassive black hole. This black hole lies at the center of a well-studied spiral galaxy called NGC 1068, located 47 million light-years away in the Cetus constellation.

    The observations revealed a clumpy, cosmic doughnut.

    “The rotating material is not a simple, rounded doughnut as originally thought, but clumpy,” said Marinucci.

    Doughnut-shaped disks of gas and dust around supermassive black holes were first proposed in the mid-1980s to explain why some black holes are hidden behind gas and dust, while others are not. The idea is that the orientation of the doughnut relative to Earth affects the way we perceive a black hole and its intense radiation. If the doughnut is viewed edge-on, the black hole is blocked. If the doughnut is viewed face-on, the black hole and its surrounding, blazing materials can be detected. This idea is referred to as the unified model because it neatly joins together the different black hole types, based solely upon orientation.

    In the past decade, astronomers have been finding hints that these doughnuts aren’t as smoothly shaped as once thought. They are more like defective, lumpy doughnuts that a doughnut shop might throw away.

    The new discovery is the first time this clumpiness has been observed in an ultra-thick doughnut, and supports the idea that this phenomenon may be common. The research is important for understanding the growth and evolution of massive black holes and their host galaxies.

    “We don’t fully understand why some supermassive black holes are so heavily obscured, or why the surrounding material is clumpy,” said co-author Poshak Gandhi of the University of Southampton in the United Kingdom. “This is a subject of hot research.”

    Both NuSTAR and [ESA]XMM-Newton observed the supermassive black hole in NGC 1068 simultaneously on two occasions between 2014 to 2015.

    ESA XMM Newton
    ESA/XMM-Newton

    On one of those occasions, in August 2014, NuSTAR observed a spike in brightness. NuSTAR observes X-rays in a higher-energy range than XMM-Newton, and those high-energy X-rays can uniquely pierce thick clouds around the black hole. The scientists say the spike in high-energy X-rays was due to a clearing in the thickness of the material entombing the supermassive black hole.

    “It’s like a cloudy day, when the clouds partially move away from the sun to let more light shine through,” said Marinucci.

    NGC 1068 is well known to astronomers as the first black hole to give birth to the unification idea. “But it is only with NuSTAR that we now have a direct glimpse of its black hole through such clouds, albeit fleeting, allowing a better test of the unification concept,” said Marinucci.

    The team says that future research will address the question of what causes the unevenness in doughnuts. The answer could come in many flavors. It’s possible that a black hole generates turbulence as it chomps on nearby material. Or, the energy given off by young stars could stir up turbulence, which would then percolate outward through the doughnut. Another possibility is that the clumps may come from material falling onto the doughnut. As galaxies form, material migrates toward the center, where the density and gravity is greatest. The material tends to fall in clumps, almost like a falling stream of water condensing into droplets as it hits the ground.

    “We’d like to figure out if the unevenness of the material is being generated from outside the doughnut, or within it,” said Gandhi.

    “These coordinated observations with NuSTAR and XMM-Newton show yet again the exciting science possible when these satellites work together,” said Daniel Stern, NuSTAR project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

    See the full article here.

    Another simpler view of NGC 1068 from Hubble:
    4

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  • richardmitnick 10:59 am on November 27, 2015 Permalink | Reply
    Tags: , , , , NASA NuSTAR   

    From JPL-Caltech: “NASA, ESA Telescopes Give Shape to Furious Black Hole Winds” 

    JPL-Caltech

    February 19, 2015
    Whitney Clavin
    Jet Propulsion Laboratory, Pasadena, California
    818-354-4673
    whitney.clavin@jpl.nasa.gov

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

    1
    Supermassive black holes at the cores of galaxies blast radiation and ultra-fast winds outward, as illustrated in this artist’s conception. New data from NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Space Agency’s (ESA’s) XMM-Newton telescopes show that these winds, which contain gases of highly ionized atoms, blow in a nearly spherical fashion, emanating in every direction, as shown in the artwork. The findings rule out the possibility that the winds blow in narrow beams.

    NASA NuSTAR
    NASA/NuSTAR

    ESA XMM Newton
    ESA/XMM-Newton

    With the shape and extent of the winds known, the researchers were able to determine the winds’ strength. The high-speed winds are powerful enough to shut down star formation throughout a galaxy.

    The artwork is based on an image of the Pinwheel galaxy (Messier 101) taken by NASA’s Hubble Space Telescope.

    NASA Hubble Telescope
    NASA/ESA Hubble

    2
    The galaxy Messier 101 (M101, also known as NGC 5457 and also nicknamed the Pinwheel Galaxy) lies in the northern circumpolar constellation, Ursa Major (The Great Bear), at a distance of about 21 million light-years from Earth. This is one of the largest and most detailed photo of a spiral galaxy that has been released from Hubble. The galaxy’s portrait is actually composed of 51 individual Hubble exposures, in addition to elements from images from ground-based photos [CFHT image: Canada-France-Hawaii Telescope/J.-C. Cuillandre/Coelum NOAO image: George Jacoby, Bruce Bohannan, Mark Hanna/NOAO/AURA/NSF.

    NuSTAR’s mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located at Malindi, Kenya. The mission’s outreach program is based at Sonoma State University, Rohnert Park, California. NASA’s Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

    2
    This plot of data from two space telescopes, NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Space Agency’s (ESA’s) XMM-Newton determines for the first time the shape of ultra-fast winds from supermassive black holes, or quasars. The winds blow in every direction, in a nearly spherical fashion, coming from both sides of a galaxy (only one side is shown here).

    The plot shows the brightness of X-ray light from an extremely luminous quasar called PDS 456, with the highest-energy rays on the right. XMM-Newton sees lower-energy X-rays, and NuSTAR, higher. XMM Newton had previously observed the extremely luminous quasar, called PDS 456, on its own in 2001. At that time, it had measured the X-rays up to an energy level of 11 kiloelectron volts. From those data, researchers detected a dip in the X-ray light, called an absorption feature (see dip in plot). The dip is caused by iron atoms — which are carried by the winds along with other matter — absorbing the X-ray light of a particular energy. What’s more, the absorption feature is ‘blueshifted,” meaning that the winds are speeding toward us (like a train’s whistle shifting to higher frequencies as it races toward you).

    In other words, the 2001 XMM-Newton data had told researchers that at least some of the winds were blowing toward us — but they didn’t reveal whether those winds were confined to a narrow beam along our line of sight, or were blowing in all directions. That’s because XMM-Newton had only detected absorption features, which by definition occur in front of a light source, in this case, the quasar. To probe what was happening to at sides of the quasar, the astronomers needed to find a different type of feature called an emission feature. These occur when iron scatters X-ray light at a particular energy in all directions, not only toward the observer.

    Enter NuSTAR to the X-ray astronomy scene, a high-energy X-ray telescope that was launched in 2012. NuSTAR and XMM-Newton teamed up to observe PDS 456 simultaneously in 2013 and 2014. The results are shown in this plot. NuSTAR data are represented as orange circles and XMM-Newton as blue squares. The NuSTAR data reveal the baseline of the “continuum” quasar light (see gray line) — or what the quasar would look like without any winds. What stands out is the bump to the left of the dips. That’s an iron emission signature, the telltale sign that the black hole winds blow to the sides and in all directions.

    XMM-Newton might have seen the emission feature before, but the feature couldn’t be identified until NuSTAR’s elucidated the baseline quasar light. For example, had the X-ray winds been confined to a beam, then NuSTAR would have seen more brightness at the higher end of the X-ray spectrum, and there would have been no iron emission feature.

    The results demonstrate that, in some cases, two telescopes are better than one at solving tricky problems. By observing the entire X-ray energy range, the astronomers were able to get a more complete picture of what is happening around the quasar.

    “We know black holes in the centers of galaxies can feed on matter, and this process can produce winds. This is thought to regulate the growth of the galaxies,” said Fiona Harrison of the California Institute of Technology (Caltech) in Pasadena, California. Harrison is the principal investigator of NuSTAR and a co-author on a new paper about these results appearing in the journal Science. “Knowing the speed, shape and size of the winds, we can now figure out how powerful they are.”

    Supermassive black holes blast matter into their host galaxies, with X-ray-emitting winds traveling at up to one-third the speed of light. In the new study, astronomers determined PDS 456, an extremely bright black hole known as a quasar more than 2 billion light-years away, sustains winds that carry more energy every second than is emitted by more than a trillion suns.

    “Now we know quasar winds significantly contribute to mass loss in a galaxy, driving out its supply of gas, which is fuel for star formation,” said the study’s lead author, Emanuele Nardini of Keele University in England.

    “This is a great example of the synergy between XMM-Newton and NuSTAR,” said Norbert Schartel, XMM-Newton project scientist at ESA. “The complementarity of these two X-ray observatories is enabling us to unveil previously hidden details about the powerful side of the universe.”

    “For an astronomer, studying PDS 456 is like a paleontologist being given a living dinosaur to study,” said study co-author Daniel Stern of NASA’s Jet Propulsion Laboratory in Pasadena. “We are able to investigate the physics of these important systems with a level of detail not possible for those found at more typical distances, during the ‘Age of Quasars.'”

    NuSTAR is a Small Explorer mission led by Caltech and managed by JPL for NASA’s Science Mission Directorate in Washington.

    For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/.

    See the full article here .

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  • richardmitnick 2:37 pm on October 10, 2015 Permalink | Reply
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    From RAS: “Universe’s hidden supermassive black holes revealed” From July but Well Worth Your Time 

    Royal Astronomical Society

    Royal Astronomical Society

    09 July 2015
    Dr Robert Massey
    Royal Astronomical Society
    Mob: +44 (0)794 124 8035
    rm@ras.org.uk

    Ms Anita Heward
    Royal Astronomical Society
    Mob: +44 (0)7756 034 243
    anitaheward@btinternet.com

    Dr Sam Lindsay
    Royal Astronomical Society
    Mob: +44 (0)7957 566 861
    sl@ras.org.uk

    Durham University Marketing and Communications Office
    Tel: +44 (0)191 334 6075
    communications.team@durham.ac.uk

    Astronomers have found evidence for a large population of hidden supermassive black holes in the Universe. Using NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) satellite observatory, the team of international scientists detected the high-energy x-rays from five supermassive black holes previously clouded from direct view by dust and gas. The findings were presented today at the Royal Astronomical Society’s National Astronomy Meeting, at Venue Cymru, in Llandudno, Wales (Monday 6 July).

    1
    NASA/Nu-STAR Credit: NASA/JPL-Caltech.

    The research, led by astronomers at Durham University, UK, supports the theory that potentially millions more supermassive black holes exist in the Universe, but are hidden from view.

    The scientists pointed NuSTAR at nine candidate hidden supermassive black holes that were thought to be extremely active at the centre of galaxies, but where the full extent of this activity was potentially obscured from view.

    High-energy x-rays found for five of the black holes confirmed that they had been hidden by dust and gas. The five were much brighter and more active than previously thought as they rapidly feasted on surrounding material and emitted large amounts of radiation.

    3
    A Hubble Space Telescope colour image of one of the nine galaxies targeted by NuSTAR. The high energy X-rays detected by NuSTAR revealed the presence of an extremely active supermassive black hole at the galaxy centre, deeply buried under a blanket of gas and dust. Credit: Hubble Legacy Archive, NASA, ESA.

    NASA Hubble Telescope
    NASA/ESA Hubble

    Such observations were not possible before NuSTAR, which launched in 2012 and is able to detect much higher energy x-rays than previous satellite observatories.

    Lead author George Lansbury, a postgraduate student in the Centre for Extragalactic Astronomy, at Durham University, said: “For a long time we have known about supermassive black holes that are not obscured by dust and gas, but we suspected that many more were hidden from our view.

    “Thanks to NuSTAR for the first time we have been able to clearly see these hidden monsters that are predicted to be there, but have previously been elusive because of their ‘buried’ state.

    “Although we have only detected five of these hidden supermassive black holes, when we extrapolate our results across the whole Universe then the predicted numbers are huge and in agreement with what we would expect to see.”

    Daniel Stern, the project scientist for NuSTAR at NASA’s Jet Propulsion Laboratory in Pasadena, California, added: “High-energy X-rays are more penetrating than low-energy X-rays, so we can see deeper into the gas burying the black holes. NuSTAR allows us to see how big the hidden monsters are and is helping us learn why only some black holes appear obscured.”

    The research was funded by the Science and Technology Facilities Council (STFC) and has been accepted for publication in The Astrophysical Journal.

    4
    An artist’s illustration of a supermassive black hole, actively feasting on its surroundings. The central black hole is hidden from direct view by a thick layer of encircling gas and dust.

    See the full article here .

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  • richardmitnick 4:11 pm on July 6, 2015 Permalink | Reply
    Tags: , , , NASA NuSTAR   

    From JPL: “NuSTAR Stares Deep into Hidden Lairs of Black Holes” 

    JPL

    July 6, 2015
    Whitney Clavin
    Jet Propulsion Laboratory, Pasadena, California
    818-354-4673
    whitney.clavin@jpl.nasa.gov

    1
    Top: An illustration of NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, in orbit. The unique school bus-long mast allows NuSTAR to focus high energy X-rays.

    Lower-left: A color image from NASA’s Hubble Space Telescope of one of the nine galaxies targeted by NuSTAR in search of hidden black holes.

    Bottom-right: An artist’s illustration of a supermassive black hole, actively feasting on its surroundings. The central black hole is hidden from direct view by a thick layer of encircling gas and dust.

    Some of the “biggest and baddest” black holes around are buried under thick blankets of gas and dust. These monsters in the middle of galaxies are actively devouring material, but their hidden nature makes observing them a challenge.

    NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) recently caught a glimpse of five of these secluded beasts. While hidden from view from most other telescopes, NuSTAR can spot them by detecting the highest-energy X-rays, which can penetrate through the enshrouding gas and dust.

    The research, led by astronomers at Durham University, United Kingdom, supports the theory that potentially millions of supermassive black holes exist in the universe hidden from view. The findings were presented today, July 6, at the Royal Astronomical Society’s National Astronomy Meeting in Llandudno, Wales.

    The scientists pointed NuSTAR at nine galaxies where supermassive black holes were thought to be extremely active but largely obscured. Five of these candidates were found to contain hidden supermassive black holes, feasting on surrounding material. What’s more, the objects were observed to be more active than previously thought.

    Such observations were not possible before NuSTAR, which launched in 2012 and is able to detect much higher-energy X-rays than previous satellite observatories.

    “Thanks to NuSTAR, for the first time, we have been able to clearly identify these hidden monsters that are predicted to be there, but have previously been elusive because of their surrounding cocoons of material,” said George Lansbury of Durham University, lead author of the findings accepted for publication in The Astrophysical Journal.

    “Although we have only detected five of these hidden supermassive black holes, when we extrapolate our results across the whole universe, then the predicted numbers are huge and in agreement with what we would expect to see.”

    Daniel Stern, the project scientist for NuSTAR at NASA’s Jet Propulsion Laboratory in Pasadena, California, added: “High-energy X-rays are more penetrating than low-energy X-rays, so we can see deeper into the gas burying the black holes. NuSTAR allows us to see how big the hidden monsters are, and is helping us learn why only some black holes appear obscured.”

    The research is funded by the Science and Technology Facilities Council.

    NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by NASA’s Jet Propulsion Laboratory, also in Pasadena, for NASA’s Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Virginia.

    For more information, visit:

    http://www.nasa.gov/nustar

    http://www.nustar.caltech.edu

    See the full article here.

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  • richardmitnick 6:29 pm on May 7, 2015 Permalink | Reply
    Tags: , , , NASA NuSTAR   

    From JPL: “Star Explosion is Lopsided, Finds NASA’s NuSTAR” 

    JPL

    May 7, 2015
    Whitney Clavin
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-4673
    whitney.clavin@jpl.nasa.gov

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

    1
    Supernova SN 1987A, one of the brightest stellar explosions since the invention of the telescope more than 400 years ago, is no stranger to the NASA/ESA Hubble Space Telescope. The observatory has been on the frontline of studies into this brilliant dying star since its launch in 1990, three years after the supernova exploded on 23 February 1987. This image of Hubble’s old friend, retreived from the telescope’s data archive, may be the best ever of this object, and reminds us of the many mysteries still surrounding it. Dominating this picture are two glowing loops of stellar material and a very bright ring surrounding the dying star at the centre of the frame. Although Hubble has provided important clues on the nature of these structures, their origin is still largely unknown. Another mystery is that of the missing neutron star. The violent death of a high-mass star, such as SN 1987A, leaves behind a stellar remnant — a neutron star or a black hole. Astronomers expect to find a neutron star in the remnants of this supernova, but they have not yet been able to peer through the dense dust to confirm it is there. The supernova belongs to the Large Magellanic Cloud, a nearby galaxy about 168 000 light-years away.

    2
    Large Magellanic Cloud

    Even though the stellar explosion took place around 166 000 BC, its light arrived here less than 25 years ago. This picture is based on observations done with the High Resolution Channel of Hubble’s Advanced Camera for Surveys [ACS].

    NASA Hubble ACS
    ACS

    The field of view is approximately 25 by 25 arcseconds. Credit: NASA/ESA Hubble

    2
    The plot of data from NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR (right), amounts to a “smoking gun” of evidence in the mystery of how massive stars explode. The observations indicate that supernovae belonging to a class called Type II or core-collapse blast apart in a lopsided fashion, with the core of the star hurtling in one direction, and the ejected material mostly expanding the other way (see diagram in Figure 1). NuSTAR made the most precise measurements yet of a radioactive element, called titanium-44, in the supernova remnant called 1987A. NuSTAR sees high-energy X-rays, as shown here in the plot ranging from 60 to more than 80 kiloelectron volts. The spectral signature of titanium-44 is apparent as the two tall peaks. The white line shows where one would expect to see these spectral signatures if the titanium were not moving. The fact that the spectral peaks have shifted to lower energies indicates that the titanium has “redshifted,” and is moving way from us. This is similar to what happens to a train’s whistle as the train leaves the station. The whistle’s sound shifts to lower frequencies. NuSTAR’s detection of redshifted titanium reveals that the bulk of material ejected in the 1987A supernova is flying way from us at a velocity of 1.6 million miles per hour (2.6 million kilometers per hour). Had the explosion been spherical in nature, the titanium would have been seen flying uniformly in all directions. This is proof that this explosion occurred in an asymmetrical fashion.

    The still unraveling remains of supernova 1987A are shown here in this image taken by NASA’s Hubble Space Telescope.

    NASA Hubble Telescope
    NASA/ESA Hubble

    The bright ring consists of material ejected from the dying star before it detonated. The ring is being lit up by the explosion’s shock wave.
    NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, has found evidence that a massive star exploded in a lopsided fashion, sending ejected material flying in one direction and the core of the star in the other.

    NASA NuSTAR
    NuSTAR

    The findings offer the best proof yet that star explosions of this type, called Type II or core-collapse supernovae, are inherently asymmetrical, a phenomenon that had been difficult to prove before now.

    “Stars are spherical objects, but apparently the process by which they die causes their cores to be turbulent, boiling and sloshing around in the seconds before their demise,” said Steve Boggs of the University of California, Berkeley, lead author of a new study on the findings, appearing in the May 8 issue of Science. “We are learning that this sloshing leads to asymmetrical explosions.”

    The supernova remnant in the study, called 1987A, is 166,000 light-years away. Light from the blast that created the remnant lit up skies above Earth in 1987. While other telescopes had found hints that this explosion was not spherical, NuSTAR found the “smoking gun” in the form of a radioisotope called titanium-44.

    “Titanium is produced in the very heart of the explosion, so it traces the shape of the engine driving the disassembly of the star,” said Fiona Harrison, the principal investigator of NuSTAR at the California Institute of Technology in Pasadena. “By looking at the shift of the energy of the X-rays coming from titanium, the NuSTAR data revealed that, surprisingly, most of the material is moving away from us.”

    Last year, NuSTAR created detailed titanium-44 maps of another supernova remnant, called Cassiopeia A, also finding evidence of an asymmetrical explosion, though not to as great an extent as in 1987A.

    c
    A false color image of Cassiopeia A (Cas A) using observations from both the Hubble and Spitzer telescopes as well as the Chandra X-ray Observatory (cropped). Date 9 June 2005

    NASA Spitzer Telescope
    Spitzer

    NASA Chandra Telescope
    Chandra

    Together, these results suggest that lopsidedness is at the very root of core-collapse supernova.

    When supernova 1987A first lit up our skies decades ago, telescopes around the world had a unique opportunity to watch the event unfold and evolve. Outer, ejected materials lit up first, followed by the innermost materials powered by radioactive isotopes, such as cobalt-56, which decayed into iron-56. In 2012, the European Space Agency’s Integral satellite detected titanium-44 in 1987A. Titanium-44 continues to blaze in the supernova remnant due to its long lifetime of 85 years.

    ESA Integral
    ESA/Integral

    “In some ways, it is as if 1987A is still exploding in front of our eyes,” said Boggs.

    NuSTAR brought a new tool to the study of 1987A. Thanks to the observatory’s sharp high-energy X-ray vision, it has made the most precise measurements of titanium-44 yet. This radioactive material is produced at the core of a supernova, so it provides astronomers with a direct probe into the mechanisms of a detonating star.

    The NuSTAR spectral data reveal that titanium-44 is moving away from us with a velocity of 1.6 million mph (2.6 million kilometers per hour). That indicates ejected material flung outward in one direction, while the compact core of the supernova, called a neutron star, seems to have kicked off in the opposite direction.

    “These explosions are driven by the formation of a compact object, the remaining core of the star, and this seems to be connected to the core blasting one direction, and the ejected material, the other,” said Boggs.

    Previous observations have hinted at the lopsided nature of supernova blasts, but it was impossible to confirm. Telescopes like NASA’s Chandra X-ray Observatory, which sees lower-energy X-rays than NuSTAR, had spotted iron that had been heated in the 1987A blast, but it was not clear if the iron was generated in the explosion or just happened to have been in the vicinity.

    “Radioactive titanium-44 glows in the X-rays no matter what and is only produced in the explosion,” said Brian Grefenstette, a co-author of the study at Caltech. “This means that we don’t have to worry about how the environment influenced the observations. We are able to directly observe the material ejected in the explosion.”

    Future studies by NuSTAR and other telescopes should further illuminate the warped nature of supernovae. Is 1987A particularly askew, or in line with other objects in its class? A decades-old mystery continues to unravel before our eyes.

    NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by NASA’s Jet Propulsion Laboratory, also in Pasadena, for NASA’s Science Mission Directorate in Washington.

    For more information, visit:

    http://www.nasa.gov/nustar

    See the full article here.

    Please help promote STEM in your local schools.

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    NASA JPL Campus

    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.

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