Tagged: NASA Chandra Toggle Comment Threads | Keyboard Shortcuts

  • 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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 2:07 pm on September 17, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From NASA/Chandra: “NASA’s Chandra X-ray Observatory Finds Planet That Makes Star Act Deceptively Old” 

    NASA Chandra

    September 16, 2014
    Media contacts:
    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

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

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

    A giant planet appears to be weakening the magnetic field of the star it closely orbits. The planet, called WASP 18b, is over ten times Jupiter’s mass but is so close to its star that it completes an orbit in less than a day. The extreme tidal forces by this “hot Jupiter” are apparently changing the internal structure of the star. Chandra data show the star is acting much older than the age astronomers estimate it to be.

    A planet may be causing the star it orbits to act much older than it actually is, according to new data from NASA’s Chandra X-ray Observatory. This discovery shows how a massive planet can affect the behavior of its parent star.

    The star, WASP 18, and its planet, WASP-18b, are located about 330 light-years from Earth. WASP-18b has a mass about 10 times that of Jupiter and completes one orbit around its star in less than 23 hours, placing WASP-18b in the “hot Jupiter” category of exoplanets, or planets outside our solar system.

    wasp
    Credit X-ray: NASA/CXC/SAO/I.Pillitteri et al; Optical: DSS; Illustration: NASA/CXC/M.Weiss
    Release Date September 16, 2014

    WASP-18b is the first known example of an orbiting planet that has apparently caused its star, which is roughly the mass of our sun, to display traits of an older star.

    “WASP-18b is an extreme exoplanet,” said Ignazio Pillitteri of the Istituto Nazionale di Astrofisica (INAF)-Osservatorio Astronomico di Palermo in Italy, who led the study. “It is one of the most massive hot Jupiters known and one of the closest to its host star, and these characteristics lead to unexpected behavior. This planet is causing its host star to act old before its time.”

    Pillitteri’s team determined – WASP-18 is between 500 million and 2 billion years old, based on theoretical models and other data. While this may sound old, it is considered young by astronomical standards. By comparison, our sun is about 5 billion years old and thought to be about halfway through its lifetime.

    Younger stars tend to be more active, exhibiting stronger magnetic fields, larger flares, and more intense X-ray emission than their older counterparts. Magnetic activity, flaring, and X-ray emission are linked to the star’s rotation, which generally declines with age. However, when astronomers took a long look with Chandra at WASP-18 they didn’t detect any X-rays. Using established relations between the magnetic activity and X-ray emission of stars, as well as its actual age, researchers determined WASP-18 is about 100 times less active than it should be.

    “We think the planet is aging the star by wreaking havoc on its innards,” said co-author Scott Wolk of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

    The researchers argue that tidal forces created by the gravitational pull of the massive planet – similar to those the moon has on Earth’s tides, but on a much larger scale – may have disrupted the magnetic field of the star.

    The strength of the magnetic field depends on the amount of convection in the star, or how intensely hot gas stirs the interior of the star.

    “The planet’s gravity may cause motions of gas in the interior of the star that weaken the convection,” said co-author Salvatore Sciortino also of INAF-Osservatorio Astronomico di Palermo in Italy. “This has a domino effect that results in the magnetic field becoming weaker and the star to age prematurely.”

    WASP-18 is particularly susceptible to this effect because its convection zone is narrower than most stars. This makes it more vulnerable to the impact of tidal forces that tug at it.

    The effect of tidal forces from the planet may also explain an unusually high amount of lithium found in earlier optical studies of WASP-18. Lithium is usually abundant in younger stars, but over time convection carries lithium to the hot inner regions of a star, where it is destroyed by nuclear reactions. If there is less convection, the lithium does not circulate into the interior of the star as much, allowing more lithium to survive.

    These results were published in the July issue of Astronomy and Astrophysics and are available online.

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 9:23 am on September 11, 2014 Permalink | Reply
    Tags: , , , , , NASA Chandra   

    From Chandra: “Puppis A: An X-ray Tapestry” 

    NASA Chandra

    Puppis A is a supernova remnant located about 7,000 light years from Earth. This new image includes data from Chandra and XMM-Newton and is the most complete and detailed X-ray view of Puppis A to date. The combined dataset reveals a delicate tapestry of X-ray light left behind by the supernova explosion.

    ESA XMM Newton
    ESA/XMM-Newton

    puppis A
    Credit X-ray: NASA/CXC/IAFE/G.Dubner et al & ESA/XMM-Newton
    Release Date September 10, 2014

    The destructive results of a powerful supernova explosion reveal themselves in a delicate tapestry of X-ray light, as seen in this image from NASA’s Chandra X-Ray Observatory and the European Space Agency’s XMM-Newton.

    The image shows the remains of a supernova that would have been witnessed on Earth about 3,700 years ago. The remnant is called Puppis A, and is around 7,000 light years away and about 10 light years across. This image provides the most complete and detailed X-ray view of Puppis A ever obtained, made by combining a mosaic of different Chandra and XMM-Newton observations. Low-energy X-rays are shown in red, medium-energy X-rays are in green and high energy X-rays are colored blue.

    These observations act as a probe of the gas surrounding Puppis A, known as the interstellar medium. The complex appearance of the remnant shows that Puppis A is expanding into an interstellar medium that probably has a knotty structure.

    Supernova explosions forge the heavy elements that can provide the raw material from which future generations of stars and planets will form. Studying how supernova remnants expand into the galaxy and interact with other material provides critical clues into our own origins.

    A paper describing these results was published in the July 2013 issue of Astronomy and Astrophysics and is available online. The first author is Gloria Dubner from the Instituto de Astronomía y Física del Espacio in Buenos Aires in Argentina.

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 9:00 am on August 29, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From NASA/Chandra: “Arches, Quintuplet, and GC Star Clusters: Rough and Crowded Neighborhood at Galactic Center” 2006 

    NASA Chandra

    The center of the Milky Way is a crowded neighborhood and not always a calm one, according to the latest image from NASA’s Chandra X-ray Observatory. In addition to the supermassive black hole at the center, the area is filled with all sorts of different inhabitants that affect and influence one another.

    gc
    Credit NASA/CXC/UMass Amherst/Q.D.Wang et al.
    Release Date July 19, 2006

    The new X-ray image shows three massive star clusters, the Arches (upper right), Quintuplet (upper center), and the GC star cluster (bottom center), which is near the enormous black hole known as Sagittarius A*. The massive stars in these clusters can themselves be very bright, point-like X-ray sources, when winds blowing off their surfaces collide with winds from an orbiting companion star. The stars in these clusters also release vast amounts of energy when they reach the ends of their lives and explode as supernovas, which, in turn, heat the material between the stars. The stars near the Galactic Center also can emit X-rays as stellar corpses — either in the form of neutron stars or black holes in binary systems — and are also seen as point-like sources in the Chandra image.

    While the individual stars in these clusters are experiencing their own hectic lives, the clusters themselves are also busy interacting with other residents of the Galactic center neighborhood. For instance, the star clusters are slamming into cooler, dense clouds of molecular gas. These powerful collisions between the clusters and clouds may result in a higher proportion of more massive stars than low-mass ones in the Galactic center, compared to a quieter neighborhood. The collisions may also explain some of the diffuse X-ray emission seen in the Chandra image.

    Over the course of several years, over two million seconds of Chandra observing time has been devoted to studying the center of the Galaxy. This latest image from Chandra represents more than 1 million seconds of time and covers the area of 168 by 130 light years across. In this image, red, green, and blue correspond to lower, medium, and high-energy X-rays respectively.

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 1:20 pm on August 28, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From NASA/Chandra : “G292.0+1.8: Supernova Explosions Stay In Shape” 2009 

    NASA Chandra

    A new study of supernova remnants allowed scientists to categorize the explosion that created them based on their shape. Supernovas that come from thermonuclear explosion on white dwarfs (known as Type Ia) produce very symmetric remnants. Another type, created when a very massive star collapses, results in more asymmetrically shaped remnants

    two
    Credit NASA/CXC/UCSC/L. Lopez et al.
    Release Date December 17, 2009

    These two supernova remnants are part of a new study from NASA’s Chandra X-ray Observatory that shows how the shape of the remnant is connected to the way the progenitor star exploded. In this study, a team of researchers examined the shapes of 17 supernova remnants in both the Milky Way galaxy and a neighbor galaxy, the Large Magellanic Cloud.

    lmc
    Large Magellanic Cloud

    The results revealed that one category of supernova explosion, known as “Type Ia,” generated a very symmetric, circular remnant. This type of supernova is thought to be caused by a thermonuclear explosion of a white dwarf, and is often used by astronomers as a “standard candle” for measuring cosmic distances. The image in the right panel, the so-called Kepler supernova remnant, represents this type of supernova.

    On the other hand, remnants tied to the “core collapse” family of supernova explosions were distinctly more asymmetric, which is seen in the morphology of the G292.0+1.8 remnant (left). The research team measured asymmetry in two ways: how spherical or elliptical the supernova remnant was and how much one side of the remnant mirrors its opposite side. In G292, the asymmetry is subtle but can be seen in elongated features defined by the brightest emission (colored white).

    Out of the 17 supernova remnants sampled, ten were independently classified as the core-collapse variety, while the remaining seven of them were classified as Type Ia. One of these, a remnant known as SNR 0548-70.4, was a bit of an “oddball”. This one was considered a Type Ia based on its chemical abundances, but has the asymmetry of a core-collapse remnant.

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 8:47 pm on August 27, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    NASA/Chandra: “Eta Carinae: our neighboring superstars” 

    NASA Chandra

    Eta Carinae is an intriguing double star system that contains one of the biggest and brightest stars in the Milky Way. X-rays from Eta Carinae give clues about the system, including how the winds from the stars interact. Astronomers have been observing Eta Carinae with Chandra since the telescope was launched in 1999.

    This star system is extremely volatile and is expected to have at least one supernova explosion in the future.

    ec2
    Credit NASA/CXC/GSFC/K.Hamaguchi, et al.
    Release Date August 26, 2014

    The Eta Carinae star system does not lack for superlatives. Not only does it contain one of the biggest and brightest stars in our galaxy, weighing at least 90 times the mass of the Sun, it also is extremely volatile and is expected to have at least one supernova explosion in the future.

    As one of the first objects observed by NASA’s Chandra X-ray Observatory after its launch some 15 years ago, this double star system continues to reveal new clues about its nature through the X-rays it generates.

    Astronomers reported extremely volatile behavior from Eta Carinae in the 19th century when it became very bright for two decades, outshining nearly every star in the entire sky. This event became known as the “Great Eruption.” Data from modern telescopes reveal that Eta Carinae threw off about 10 times the Sun’s mass during that time. Surprisingly, the star survived this tumultuous expulsion of material, adding “extremely hardy” to its list of attributes.

    Today, astronomers are trying to learn more about the two stars in the Eta Carinae system and how they interact with each other. The heavier of the two stars is quickly losing mass through wind streaming away from its surface at over a million miles per hour. While not the giant purge of the Great Eruption, this star is still losing mass at a very high rate that will add up to the Sun’s mass in about a millennium.

    Though smaller than its partner, the companion star in Eta Carinae is also massive, weighing in at about 30 times the mass of the Sun. It is losing matter at a rate that is about 100 times lower than its partner, but still a prodigious weight loss compared to most other stars. The companion star beats the bigger star in wind speed, with its wind clocking in almost ten times faster.

    When these two speedy and powerful winds collide, they form a bow shock — similar to the sonic boom from a supersonic airplane — that then heats the gas between the stars. The temperature of the gas reaches about 10 million degrees, producing X-rays that Chandra detects.

    The Chandra image of Eta Carinae shows low-energy X-rays in red, medium-energy X-rays in green, and high-energy X-rays in blue. Most of the emission comes from low- and high-energy X-rays. The blue point source is generated by the colliding winds, and the diffuse blue emission is produced when the material that was purged during the Great Eruption reflects these X-rays. The low-energy X-rays farther out show where the winds from the two stars, or perhaps material from the Great Eruption, are striking surrounding material. This surrounding material might consist of gas that was ejected before the Great Eruption.

    An interesting feature of the Eta Carinae system is that the two stars travel around each other along highly elliptical paths during their 5.5-year-long orbit. Depending on where each star is on its oval-shaped trajectory, the distance between the two stars changes by a factor of 20. These oval-shaped trajectories give astronomers a chance to study what happens to the winds from these stars when they collide at different distances from one another.

    Throughout most of the system’s orbit, the X-rays are stronger at the apex, the region where the winds collide head-on. However, when the two stars are at their closest during their orbit — a point that astronomers call “periastron” — the X-ray emission dips unexpectedly.

    To understand the cause of this dip, astronomers observed Eta Carinae with Chandra at periastron in early 2009. The results provided the first detailed picture of X-ray emission from the colliding winds in Eta Carinae. The study suggests that part of the reason for the dip at periastron is that X-rays from the apex are blocked by the dense wind from the more massive star in Eta Carinae or perhaps by the surface of the star itself.

    Another factor responsible for the X-ray dip is that the shock wave appears to be disrupted near periastron, possibly because of faster cooling of the gas due to increased density and/or a decrease in the strength of the companion star’s wind because of extra ultraviolet radiation from the massive star reaching it. Researchers are hoping that Chandra observations of the latest periastron in August 2014 will help them determine the true explanation.

    These results were published in the April 1, 2014 issue of The Astrophysical Journal and are available online. The first author of the paper is Kenji Hamaguchi of Goddard Space Flight Center in Greenbelt, MD, and his co-authors are Michael Corcoran of Goddard Space Flight Center (GSFC); Christopher Russell of University of Delaware in Newark; A. Pollock from the European Space Agency in Madrid, Spain; Theodore Gull, Mairan Teodoro, and Thomas I. Madura from GSFC; Augusto Damineli from Universidade de Sao Paulo in Sao Paulo, Brazil and Julian Pittard from the University of Leeds in the UK.

    See the full article here.

    Another view, this from Hubble:

    ec
    A huge, billowing pair of gas and dust clouds are captured in this stunning NASA Hubble Space Telescope image of the supermassive star Eta Carinae. Eta Carinae was observed by Hubble in September 1995 with the Wide Field and Planetary Camera 2 (WFPC2).

    NASA Hubble WFPC2
    WFPC2 (no longer in service)

    Images taken through red and near-ultraviolet filters were subsequently combined to produce the color image shown. A sequence of eight exposures was necessary to cover the object’s huge dynamic range: the outer ejecta blobs are 100,000 times fainter than the brilliant central star. Eta Carinae suffered a giant outburst about 160 years ago, when it became one of the brightest stars in the southern sky. Though the star released as much visible light as a supernova explosion, it survived the outburst. The explosion produced two lobes and a large, thin equatorial disk, all moving outward at about 1 million kilometers per hour.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 12:58 pm on August 25, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From NASA/ Chandra: “M31: Nearby Black Hole is Feeble and Unpredictable” 2010 

    NASA Chandra

    The large image here shows an optical view, with the Digitized Sky Survey, of the Andromeda Galaxy, otherwise known as M31. The inset shows Chandra X-ray Observatory images of a small region in the center of Andromeda. The image on the left shows the sum of 23 images taken with Chandra’s High Resolution Camera (HRC) before January 2006 and the image on the right shows the sum of 17 HRC images taken after January 2006. Before 2006, three X-ray sources are clearly visible in the Chandra image, including one faint source close to the center of the image. After 2006, a fourth source, called M31*, appears just below and to the right of the central source, produced by material falling onto the supermassive black hole in M31.

    M31
    Credit X-ray (NASA/CXC/SAO/Li et al.), Optical (DSS)
    Release Date May 25, 2010

    A detailed study of Chandra observations over ten years shows that M31* was in a very dim, or quiet, state from 1999 to the beginning of 2006. However, on January 6, 2006, the black hole became more than a hundred times brighter, suggesting an outburst of X-rays. This was the first time such an event had been seen from a supermassive black hole in the nearby, local universe. After the outburst, M31* entered another relatively dim state, but was almost ten times brighter on average than before 2006. The outburst suggests a relatively high rate of matter falling onto M31* followed by a smaller, but still significant rate.

    Just like the supermassive black hole in the center of the Milky Way, M31* is surprisingly quiet. In fact, Andromeda’s black hole is ten to one hundred thousand times fainter in X-ray light that astronomers might expect given the reservoir of gas around it. The black holes in both Andromeda and the Milky Way provide special laboratories to study the dimmest type of accretion ever seen onto a supermassive black hole.

    See the full article here.

    Just for reference:

    androedia
    The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda. The image also shows Messier Objects 32 and 110, as well as NGC 206 (a bright star cloud in the Andromeda Galaxy) and the star Nu Andromedae. This image was taken using a hydrogen-alpha filter.
    Adam Evans

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 11:45 am on August 23, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra, ,   

    From NASA: The Three Great Observatories 

    NASA

    NASA

    Described as the “three great observatories, Spitzer, Hubble and Chandra have each revolutionized our view of the Universe. Please watch, enjoy and learn.

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

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

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

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


    ScienceSprings is powered by MAINGEAR computers

     
  • richardmitnick 11:59 am on August 20, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From NASA/Chandra- “M82 SN2014J: NASA’s Chandra Observatory Searches for Trigger of Nearby Supernova “ 

    NASA Chandra

    Chandra data is being used to help determine what caused SN 2014J to explode. Astronomers first spotted SN 2014J in the M82 galaxy on January 21, 2014, making it one of the closest supernovas discovered in decades. SN 2014J is a Type Ia supernova, an important class of objects used to measure the expansion of the Universe. The non-detection of X-rays from Chandra gives information about the environment around the star before SN 2014J exploded.

    m82
    Credit NASA/CXC/SAO/R.Margutti et al
    Release Date August 14, 2014

    New data from NASA’s Chandra X-ray Observatory has provided stringent constraints on the environment around one of the closest supernovas discovered in decades. The Chandra results provide insight into possible cause of the explosion, as described in our press release.

    On January 21, 2014, astronomers witnessed a supernova soon after it exploded in the Messier 82, or M82, galaxy. Telescopes across the globe and in space turned their attention to study this newly exploded star, including Chandra. Astronomers determined that this supernova, dubbed SN 2014J, belongs to a class of explosions called “Type Ia” supernovas. These supernovas are used as cosmic distance-markers and played a key role in the discovery of the Universe’s accelerated expansion, which has been attributed to the effects of dark energy. Scientists think that all Type Ia supernovas involve the detonation of a white dwarf. One important question is whether the fuse on the explosion is lit when the white dwarf pulls too much material from a companion star like the Sun, or when two white dwarf stars merge. This image contains Chandra data, where low, medium, and high-energy X- rays are red, green, and blue respectively. The boxes in the bottom of the image show close-up views of the region around the supernova in data taken prior to the explosion (left), as well as data gathered on February 3, 2014, after the supernova went off (right). The lack of X-rays detected by Chandra is an important clue for astronomers looking for the exact mechanism of how this star exploded.

    The non-detection of X-rays reveals that the region around the site of the supernova explosion is relatively devoid of material. Astronomers expect that if a white dwarf exploded because it had been steadily collecting matter from a companion star prior to exploding, the mass transfer process would not be 100% efficient, and the white dwarf would be immersed in a cloud of gas. If a significant amount of material were surrounding the doomed star, the blast wave generated by the supernova would have struck it by the time of the Chandra observation, producing a bright X-ray source. Since they do not detect any X-rays, the researchers determined that the region around SN 2014J is exceptionally clean.

    A viable candidate for the cause of SN 2014J must explain the relatively gas-free environment around the star prior to the explosion. One possibility is the merger of two white dwarf stars, in which case there might have been little mass transfer and pollution of the environment before the explosion. Another is that several smaller eruptions on the surface of the white dwarf cleared the region prior to the supernova. Further observations a few hundred days after the explosion could shed light on the amount of gas in a larger volume, and help decide between these and other scenarios.

    A paper describing these results was published in the July 20 issue of The Astrophysical Journal and is available online. The first author is Raffaella Margutti from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, MA, and the co-authors are Jerod Parrent (CfA), Atish Kamble (CfA), Alicia Soderberg (CfA), Ryan Foley (University of Illinois at Urbana-Champaign), Dan Milisavljevic (CfA), Maria Drout (CfA), and Robert Kirshner (CfA).

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 3:20 pm on August 14, 2014 Permalink | Reply
    Tags: , , , , NASA Chandra   

    From NASA/Chandra: “NASA’s Chandra Observatory Searches for Trigger of Nearby Supernova” 

    NASA Chandra

    August 14, 2014
    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

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

    New data from NASA’s Chandra X-ray Observatory offer a glimpse into the environment of a star before it exploded earlier this year, and insight into what triggered one of the closest supernovas witnessed in decades.

    snova
    NASA’s Chandra X-ray Observatory is helping determine what caused SN 2014J, one of the closest supernovas discovered in decades. By comparing X-ray data taken before and after the stellar explosion, scientists can learn more about what set it off.
    Image Credit: NASA/SAO/CXC/R. Margutti et al

    The data gathered on the Jan. 21 explosion, a Type Ia supernova, allowed scientists to rule out one possible cause. These supernovas may be triggered when a white dwarf takes on too much mass from its companion star, immersing it in a cloud of gas that produces a significant source of X-rays after the explosion.

    wd
    In 1863, a telescope maker named Alvan Clark discovered why a star known as Sirius seemed to wobble back and forth. It had a companion star, difficult to see because it is a white dwarf — the faintly glowing lump of carbon that is left over after stars burn through their fuel. The binary system is now known as Sirius A and Sirius B, and white dwarf stars have fascinated astronomers ever since.

    Astronomers used NASA’s Swift and Chandra telescopes to search the nearby Messier 82 galaxy, the location of the explosion, for such an X-ray source. However, no source was found, revealing the region around the site of the supernova is relatively devoid of material.

    NASA SWIFT Telescope
    NASA/SWIFT

    “While it may sound a bit odd, we actually learned a great deal about this supernova by detecting absolutely nothing,” said Raffaella Margutti of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, who led the study. “Now we can essentially rule out that the explosion was caused by a white dwarf continuously pulling material from a companion star.”

    This supernova, SN 2014J, could instead have been caused by the merger of two white dwarf stars, an event that should result in little or no X-rays after the explosion. Further observations could rule out or confirm other possible triggers.

    [The supernova was discovered by astronomer Steve Fossey, of University College London. Fossey was training four undergraduate students (Ben Cooke, Guy Pollack, Matthew Wilde and Thomas Wright) to use a small 0.35-metre (14 in) telescope at University of London Observatory, located in Mill Hill, north London.

    University of London Mill Hill Observatory
    MIll HIll Observatory

    The discovery was serendipitous, because Fossey was not searching for supernovae and wanted to take advantage of a short gap in the cloud cover. He later said that “The weather was closing in, with increasing cloud, so instead of the planned practical astronomy class, I gave the students an introductory demonstration of how to use the CCD camera on one of the observatory’s automated 0.35–metre telescopes.”

    At 19:20 GMT on 21 January 2014, Fossey and his students noticed a bright new star in their images of the galaxy Messier 82, also known as the Cigar Galaxy.[6] After comparing their image to archival ones of the same galaxy, they used observations with a second telescope to eliminate the possibility of an instrumental artefact. Their discovery was reported to the International Astronomical Union’s Central Bureau for Astronomical Telegrams, who confirmed that they were the first to spot the supernova and assigned it the name SN 2014J as the tenth supernova discovered in 2014.]

    “Being able to eliminate one of the main possible explanations for what caused SN 2014J to explode is a big step,” said CfA’s Atish Kamble, a co-author of the study. “The next step is to narrow things down even further.”

    Type Ia supernovas are used as cosmic distance-markers [standard candles], and have played a key role in the discovery of the universe’s accelerated expansion. At about 12 million light-years from Earth, SN 2014J and its host galaxy are close — from a cosmic perspective. This offers scientists a chance to observe details that would be too hard to detect in more distant supernovas.

    “It’s crucial that we understand exactly how these stars explode because so much is riding on our observations of them for cosmology,” said co-author Jerod Parrent also from CfA. “SN 2014J might be a chance of a lifetime to study one of these supernovas in detail as it happens.”

    The study of SN 2014J is similar to a study led by Margutti about another supernova, SN 2011fe, in the nearby galaxy M101.

    This study was conducted by CfA’s Supernova Forensics Team, led by Alicia Soderberg. The results were published online and in the July 20 print issue of The Astrophysical Journal.

    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.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
Follow

Get every new post delivered to your Inbox.

Join 322 other followers

%d bloggers like this: