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  • richardmitnick 8:16 pm on January 6, 2020 Permalink | Reply
    Tags: "Famous Black Hole Has Jet Pushing Cosmic Speed Limit", , , , , , , NASA Chandra   

    From NASA Chandra: “Famous Black Hole Has Jet Pushing Cosmic Speed Limit” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

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    Credit: NASA/CXC/SAO/B.Snios et al.

    1.6.20

    The Event Horizon Telescope Collaboration released the first image of a black hole with observations of the massive, dark object at the center of Messier 87 last April.

    The first image of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    Now iconic image of Katie Bouman-Harvard Smithsonian Astrophysical Observatory after the image of Messier 87 was achieved. Headed from Harvard to Caltech as an Assistant Professional. On the committee for the next iteration of the EHT .

    EHT map

    This black hole has a mass of about 6.5 billion times that of the sun and is located about 55 million light years from Earth. The black hole has been called M87* by astronomers and has recently been given the Hawaiian name of “Powehi.”

    For years, astronomers have observed radiation from a jet of high energy particles — powered by the black hole — blasting out of the center of Messier 87. They have studied the jet in radio, optical, and X-ray light, including with Chandra. And now by using Chandra observations, researchers have seen that sections of the jet are moving at nearly the speed of light.

    “This is the first time such extreme speeds by a black hole’s jet have been recorded using X-ray data,” said Ralph Kraft of the Center of Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Mass., who presented the study at the American Astronomical Society meeting in Honolulu, Hawaii. “We needed the sharp X-ray vision of Chandra to make these measurements.”

    When matter gets close enough to a black hole, it enters into a swirling pattern called an accretion disk. Some material from the inner part of the accretion disk falls onto the black hole and some of it is redirected away from the black hole in the form of narrow beams, or jets, of material along magnetic field lines. Because this infall process is irregular, the jets are made of clumps or knots that can sometimes be identified with Chandra and other telescopes.

    The researchers used Chandra observations from 2012 and 2017 to track the motion of two X-ray knots located within the jet about 900 and 2,500 light years away from the black hole. The X-ray data show motion with apparent speeds of 6.3 times the speed of light for the X-ray knot closer to the black hole and 2.4 times the speed of light for the other.

    “One of the unbreakable laws of physics is that nothing can move faster than the speed of light,” said co-author Brad Snios, also of the CfA. “We haven’t broken physics, but we have found an example of an amazing phenomenon called superluminal motion.”

    Superluminal motion occurs when objects are traveling close to the speed of light along a direction that is close to our line of sight. The jet travels almost as quickly towards us as the light it generates, giving the illusion that the jet’s motion is much more rapid than the speed of light. In the case of M87*, the jet is pointing close to our direction, resulting in these exotic apparent speeds.

    Astronomers have previously seen such motion in Messier 87*’s jet at radio and optical wavelengths, but they have not been able to definitively show that matter in the jet is moving at very close to the speed of light. For example, the moving features could be a wave or a shock, similar to a sonic boom from a supersonic plane, rather than tracing the motions of matter.

    This latest result shows the ability of X-rays to act as an accurate cosmic speed gun. The team observed that the feature moving with an apparent speed of 6.3 times the speed of light also faded by over 70% between 2012 and 2017. This fading was likely caused by particles’ loss of energy due to the radiation produced as they spiral around a magnetic field. For this to occur the team must be seeing X-rays from the same particles at both times, and not a moving wave.

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    Illustration of the Supermassive Black Hole at the Center of Messier 87 (Credit: NASA/CXC/M.Weiss)

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    Chandra Wide-field View of Messier 87; box shows the approximate location of the wide-field jet image above (Credit: NASA/CXC)


    A Quick Look at the Black Hole Jet in Messier 87

    “Our work gives the strongest evidence yet that particles in Messier 87*’s jet are actually traveling at close to the cosmic speed limit”, said Snios.

    The Chandra data are an excellent complement to the EHT data. The size of the ring around the black hole seen with the Event Horizon Telescope is about a hundred million times smaller than the size of the jet seen with Chandra.

    Another difference is that the EHT observed Messier 87 over six days in April 2017, giving a recent snapshot of the black hole. The Chandra observations investigate ejected material within the jet that was launched from the black hole hundreds and thousands of years earlier.

    “It’s like the Event Horizon Telescope is giving a close-up view of a rocket launcher,” said the CfA’s Paul Nulsen, another co-author of the study, “and Chandra is showing us the rockets in flight.”

    In addition to being presented at the AAS meeting, these results are also described in a paper in The Astrophysical Journal led by Brad Snios.
    Other materials about the findings are available at:
    http://chandra.si.edu

    For more Chandra images, multimedia and related materials, visit:
    http://www.nasa.gov/chandra

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

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 12:07 am on January 6, 2020 Permalink | Reply
    Tags: "NASA's Great Observatories Help Astronomers Build a 3D Visualization of Exploded Star", , , , , NASA Chandra, ,   

    From NASA/ESA Hubble Telescope: “NASA’s Great Observatories Help Astronomers Build a 3D Visualization of Exploded Star” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    January 05, 2020

    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

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

    Frank Summers
    Space Telescope Science Institute, Baltimore, Maryland
    summers@stsci.edu

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    Summary
    Movie Dissects the Nebula’s Intricate Nested Structure

    In the year 1054 AD, Chinese sky watchers witnessed the sudden appearance of a “new star” in the heavens, which they recorded as six times brighter than Venus, making it the brightest observed stellar event in recorded history.

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    Crab Nebula

    This “guest star,” as they described it, was so bright that people saw it in the sky during the day for almost a month. Native Americans also recorded its mysterious appearance in petroglyphs.

    Observing the nebula with the largest telescope of the time, Lord Rosse in 1844 named the object the “Crab” because of its tentacle-like structure. But it wasn’t until the 1900s that astronomers realized the nebula was the surviving relic of the 1054 supernova, the explosion of a massive star.

    Now, astronomers and visualization specialists from the NASA’s Universe of Learning program have combined the visible, infrared, and X-ray vision of NASA’s Great Observatories to create a three-dimensional representation of the dynamic Crab Nebula.

    The multiwavelength computer graphics visualization is based on images from the Chandra X-ray Observatory and the Hubble and Spitzer space telescopes.

    NASA/Chandra X-ray Telescope

    NASA/Spitzer Infrared Telescope

    Astronomers and visualization specialists from the NASA’s Universe of Learning program
    have combined the visible, infrared, and X-ray vision of NASA’s Great Observatories to create a three-dimensional representation of the dynamic Crab Nebula, the tattered remains of an exploded star.

    The multiwavelength computer graphics visualization is based on images from the Chandra X-ray Observatory and the Hubble
    and Spitzer space telescopes.

    The approximately four-minute video dissects the intricate nested structure that makes up this stellar corpse, giving viewers a better understanding of the extreme and complex physical processes powering the nebula. The powerhouse “engine” energizing the entire system is a pulsar, a rapidly spinning neutron star, the super-dense crushed core of the exploded star. The tiny dynamo is blasting out blistering pulses of radiation 30 times a second with unbelievable clockwork precision.

    The visualization was produced by a team at the Space Telescope Science Institute (STScI) in Baltimore, Maryland; the Caltech/IPAC in Pasadena, California; and the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts. It will debut at the American Astronomical Society meeting in Honolulu, Hawaii. The movie is available to planetariums and other centers of informal learning worldwide.

    “Seeing two-dimensional images of an object, especially of a complex structure like the Crab Nebula, doesn’t give you a good idea of its three-dimensional nature,” explained STScI’s visualization scientist Frank Summers, who led the team that developed the movie. “With this scientific interpretation, we want to help people understand the Crab Nebula’s nested and interconnected geometry. The interplay of the multiwavelength observations illuminate all of these structures. Without combining X-ray, infrared, and visible light, you don’t get the full picture.”

    Certain structures and processes, driven by the pulsar engine at the heart of the nebula, are best seen at particular wavelengths.

    The movie begins by showing the Crab Nebula in context, pinpointing its location in the constellation Taurus. This view zooms in to present the Hubble, Spitzer, and Chandra images of the Crab Nebula, each highlighting one of the nested structures in the system. The video then begins a slow buildup of the three-dimensional X-ray structure, showing the pulsar and a ringed disk of energized material, and adding jets of particles firing off from opposite sides of the energetic dynamo.

    Appearing next is a rotating infrared view of a cloud enveloping the pulsar system, and glowing from synchrotron radiation. This distinctive form of radiation occurs when streams of charged particles spiral around magnetic field lines. There is also infrared emission from dust and gas.

    The visible-light outer shell of the Crab Nebula appears next. Looking like a cage around the entire system, this shell of glowing gas consists of tentacle-shaped filaments of ionized oxygen (oxygen missing one or more electrons). The tsunami of particles unleashed by the pulsar is pushing on this expanding debris cloud like an animal rattling its cage.

    The X-ray, infrared, and visible-light models are combined at the end of the movie to reveal both a rotating three-dimensional multiwavelength view and the corresponding two-dimensional multiwavelength image of the Crab Nebula.

    The three-dimensional structures serve as scientifically informed approximations for imagining the nebula. “The three-dimensional views of each nested structure give you an idea of its true dimensions,” Summers said. “To enable viewers to develop a complete mental model, we wanted to show each structure separately, from the ringed disk and jets in stark relief, to the synchrotron radiation as a cloud around that, and then the visible light as a cage structure surrounding the entire system.”

    These nested structures are particular to the Crab Nebula. They reveal that the nebula is not a classic supernova remnant as once commonly thought. Instead, the system is better classified as a pulsar wind nebula. A traditional supernova remnant consists of a blast wave, and debris from the supernova that has been heated to millions of degrees. In a pulsar wind nebula, the system’s inner region consists of lower-temperature gas that is heated up to thousands of degrees by the high-energy synchrotron radiation.

    “It is truly via the multiwavelength structure that you can more cleanly comprehend that it’s a pulsar wind nebula,” Summers said. “This is an important learning objective. You can understand the energy from the pulsar at the core moving out to the synchrotron cloud, and then further out to the filaments of the cage.”

    Summers and the STScI visualization team worked with Robert Hurt, lead visualization scientist at IPAC, on the Spitzer images; and Nancy Wolk, imaging processing specialist at the Chandra X-ray Center at the CfA, on the Chandra images. Their initial step was reviewing past research on the Crab Nebula, an intensely studied object that formed from a supernova seen in 1054 by Chinese astronomers.

    Starting with the two-dimensional Hubble, Spitzer, and Chandra images, the team worked with experts to analyze the complex nested structures comprising the nebula and identify the best wavelength to represent each component. The three-dimensional interpretation is guided by scientific data, knowledge, and intuition, with artistic features filling out the structures.

    The visualization is one of a new generation of products and experiences being developed by the NASA’s Universe of Learning program. The effort combines a direct connection to the science and scientists of NASA’s Astrophysics missions with attention to audience needs to enable youth, families, and lifelong learners to explore fundamental questions in science, experience how science is done, and discover the universe for themselves.

    This video demonstrates the power of multiwavelength astronomy. It helps audiences understand how and why astronomers use multiple regions of the electromagnetic spectrum to explore and learn about our universe.

    NASA’s Universe of Learning materials are based upon work supported by NASA under cooperative agreement award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Jet Propulsion Laboratory, CfA, and Sonoma State University.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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    AURA Icon

     
  • richardmitnick 2:22 pm on December 17, 2019 Permalink | Reply
    Tags: "Galaxy Gathering Brings Warmth", , , , , NASA Chandra, NGC 6338, Two groups of galaxies are slamming into each other at about 4 million miles per hour.   

    From NASA Chandra: “Galaxy Gathering Brings Warmth” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    December 17, 2019

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    Two groups of galaxies are slamming into each other at about 4 million miles per hour.

    Galaxies often exist in groups or clusters that can contain many individual galaxies bound together by gravity.

    Astronomers studied this collision using Chandra, XMM-Newton, the Giant Metrewave Radio Telescope, and the Apache Point Observatory.

    By studying mergers like this, astronomers can learn more about galaxy groups grow and evolve over time.

    As the holiday season approaches, people in the northern hemisphere will gather indoors to stay warm. In keeping with the season, astronomers have studied two groups of galaxies that are rushing together and producing their own warmth.

    The majority of galaxies do not exist in isolation. Rather, they are bound to other galaxies through gravity either in relatively small numbers known as “galaxy groups,” or much larger concentrations called “galaxy clusters” consisting of hundreds or thousands of galaxies. Sometimes, these collections of galaxies are drawn toward one another by gravity and eventually merge.

    Using NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton, the Giant Metrewave Radio Telescope (GMRT), and optical observations with the Apache Point Observatory in New Mexico, a team of astronomers has found that two galaxy groups are smashing into each other at a remarkable speed of about 4 million miles per hour. This could be the most violent collision yet seen between two galaxy groups.

    ESA/XMM Newton

    Giant Metrewave Radio Telescope, an array of thirty telecopes, located near Pune in India

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft)

    The system is called NGC 6338, which is located about 380 million light years from Earth. This composite image contains X-ray data from Chandra (displayed in red) that shows hot gas with temperatures upward of about 20 million degrees Celsius, as well as cooler gas detected with Chandra and XMM (shown in blue) that also emits X-rays. The Chandra data have been combined with optical data from the Sloan Digital Sky Survey, showing the galaxies and stars in white.

    The researchers estimate that the total mass contained in NGC 6338 is about 100 trillion times the mass of the Sun. This significant heft, roughly 83% of which is in the form of dark matter, 16% is in the form of hot gas, and 1% in stars, indicates that the galaxy groups are destined to become a galaxy cluster in the future. The collision and merger will complete, and the system will continue to accumulate more galaxies through gravity.

    Previous studies of NGC 6338 have provided evidence for the regions of cooler, X-ray emitting gas around the centers of the two galaxy groups (known as “cool cores”). This information has helped astronomers to reconstruct the geometry of the system, revealing that the collision between the galaxy groups happened almost along the line of sight to Earth. This finding has been confirmed with the new study.

    The new Chandra and XMM-Newton data also show that the gas to the left and right of the cool cores, and in between them, appears to have been heated by shock fronts — similar to the sonic booms created by supersonic aircraft — formed by the collision of the two galaxy groups. This pattern of shock-heated gas has been predicted by computer simulations, but NGC 6338 may be the first merger of galaxy groups to clearly show it. Such heating will prevent some of the hot gas from cooling down to form new stars.

    A second source of heat commonly found in groups and clusters of galaxies is energy provided by outbursts and jets of high-speed particles generated by supermassive black holes. Currently this source of heat appears to be inactive in NGC 6338 because there is no evidence for jets from supermassive black holes using radio data from the GMRT. This absence may explain the filaments of cooling gas detected in X-ray and optical data around the large galaxy in the center of the cool core in the south. The filters used in the composite image do not show the optical filaments, and the X-ray filaments are the small, finger-like structures emanating from the center of the cool core in the south, at approximately 2 o’clock, 7 o’clock and 8 o’clock.

    A paper describing these results was published in the September 2019 issue of the Monthly Notices of the Royal Astronomical Society. The first author is Ewan O’Sullivan of the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts, and the co-authors are Gerrit Schellenberger (CfA), Doug Burke (CfA), Ming Sun (University of Alabama in Huntsville, Alabama), Jan Vrtilek (CfA), Larry David (CfA) and Craig Sarazin (University of Virginia, Virginia).


    A Quick Look at Galaxy Gathering Brings Warmth

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 5:10 pm on November 26, 2019 Permalink | Reply
    Tags: "Black Hole Nurtures Baby Stars a Million Light Years Away", , , , , NASA Chandra   

    From NASA Chandra: “Black Hole Nurtures Baby Stars a Million Light Years Away” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    November 26, 2019

    One black hole is influencing the rate of star formation in multiple galaxies and across vast distances.

    This is a rare example of “positive feedback” where a black hole is helping to spur star formation, not suppress it.

    Researchers used X-rays from Chandra, radio waves from the VLA, and optical light from ground-based telescopes to make this discovery.

    If confirmed, this result would represent the largest distance over which a black hole has boosted the birth of stars.


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    Radio

    Black holes are famous for ripping objects apart, including stars. But now, astronomers have uncovered a black hole that may have sparked the births of stars over a mind-boggling distance, and across multiple galaxies.

    If confirmed, this discovery, made with NASA’s Chandra X-ray Observatory and other telescopes, would represent the widest reach ever seen for a black hole acting as a stellar kick-starter. The black hole seems to have enhanced star formation more than one million light years away. (One light year is equal to 6 trillion miles.)

    “This is the first time we’ve seen a single black hole boost star birth in more than one galaxy at a time,” said Roberto Gilli of the National Institute of Astrophysics (INAF) in Bologna, Italy, lead author of the study describing the discovery. “It’s amazing to think one galaxy’s black hole can have a say in what happens in other galaxies millions of trillions of miles away.”

    A black hole is an extremely dense object from which no light can escape. The black hole’s immense gravity pulls in surrounding gas and dust, but particles from a small amount of that material can also get catapulted away instead at nearly the speed of light. These fast-moving particles form two narrow beams or “jets” near the poles of the black hole.

    The supermassive black hole scientists observed in the new study is located in the center of a galaxy about 9.9 billion light years from Earth. This galaxy has at least seven neighboring galaxies, according to observations with the European Southern Observatory’s Very Large Telescope (VLT) and the Large Binocular Telescope (LBT).

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

    U Arizona Large Binocular Telescope, Interferometer, or LBTI, is a ground-based instrument connecting two 8-meter class telescopes on Mount Graham, Arizona, USA, Altitude 3,221 m (10,568 ft.) to form the largest single-mount telescope in the world. The interferometer is designed to detect and study stars and planets outside our solar system. Image credit: NASA/JPL-Caltech.

    Using the National Science Foundation’s Karl Jansky Very Large Array, scientists had previously detected radio-wave emission from a jet of high-energy particles that is about a million light years long.

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    The jet can be traced back to the supermassive black hole, which Chandra detected as a powerful source of X-rays produced by hot gas swirling around the black hole. Gilli and colleagues also detected a diffuse cloud of X-ray emission surrounding one end of the radio jet. This X-ray emission is most likely from a gigantic bubble of hot gas heated by the interaction of the energetic particles in the radio jet with surrounding matter.

    As the hot bubble expanded and swept through four neighboring galaxies, it could have created a shock wave that compressed cool gas in the galaxies, causing stars to form. All four galaxies are approximately the same distance, about 400,000 light years, from the center of the bubble. The authors estimate that the star formation rate is between about two to five times higher than typical galaxies with similar masses and distance from Earth.

    “The story of King Midas talks of his magic touch that can turn metal into gold,” said co-author Marco Mignoli, also of INAF in Bologna, Italy. “Here we have a case of a black hole that helped turn gas into stars, and its reach is intergalactic.”

    Astronomers have seen many cases where a black hole affects its surroundings through “negative feedback” — in other words, curtailing the formation of new stars. This can occur when the black hole’s jets inject so much energy into the hot gas of a galaxy, or galaxy cluster, that the gas can’t cool down enough to make large numbers of stars.

    In this newly discovered collection of galaxies, astronomers have found a less common example of “positive feedback,” where the black hole’s effects increase star formation. Moreover, when astronomers previously encountered positive feedback, it either involved increases in the star formation rate of 30% or less, or it occurred over scales of only about 20,000 to 50,000 light years on a nearby companion galaxy. Whether the feedback is positive or negative depends on a delicate balance between the heating rate and cooling rate of a cloud. That is because clouds that are initially cooler when hit by a shock wave are more prone to experience positive feedback, and form more stars.

    “Black holes have a well-earned reputation for being powerful and deadly, but not always,” said co-author Alessandro Peca, formerly at INAF in Bologna and now a Ph.D. student at the University of Miami. “This is a prime example that they sometimes defy that stereotype and can be nurturing instead.”

    The researchers used a total of six days of Chandra observing time spread out over five months.

    “It’s only because of this very deep observation that we saw the hot gas bubble produced by the black hole,” said co-author Colin Norman of the Johns Hopkins University in Baltimore, Maryland. “By targeting objects similar to this one, we may discover that positive feedback is very common in the formation of groups and clusters of galaxies.”

    A paper describing these results has been published in the most recent issue of the journal Astronomy and Astrophysics.

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

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 2:33 pm on November 19, 2019 Permalink | Reply
    Tags: "A Weakened Black Hole Allows Its Galaxy to Awaken", , , , , NASA Chandra   

    From NASA Chandra: “A Weakened Black Hole Allows Its Galaxy to Awaken” 

    NASA Chandra Banner

    NASA/Chandra Telescope

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)


    From NASA Chandra
    Press Image, Caption, and Videos

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    Credit: X-ray: NASA/CXC/MIT/M.McDonald et al; Radio: NRAO/VLA; Optical: NASA/STScI

    Astronomers have confirmed the first example of a galaxy cluster where large numbers of stars are being born at its core. Using data from NASA space telescopes and a National Science Foundation radio observatory, researchers have gathered new details about how the most massive black holes in the universe affect their host galaxies.

    Galaxy clusters are the largest structures in the cosmos that are held together by gravity, consisting of hundreds or thousands of galaxies embedded in hot gas, as well as invisible dark matter. The largest supermassive black holes known are in galaxies at the centers of these clusters.

    For decades, astronomers have looked for galaxy clusters containing rich nurseries of stars in their central galaxies. Instead, they found powerful, giant black holes pumping out energy through jets of high-energy particles and keeping the gas too warm to form many stars.

    Now, scientists have compelling evidence for a galaxy cluster where stars are forming at a furious rate, apparently linked to a less effective black hole in its center. In this unique cluster, the jets from the central black hole instead appear to be aiding in the formation of stars. Researchers used new data from NASA’s Chandra X-ray Observatory and Hubble Space Telescope, and the NSF’s Karl Jansky Very Large Array (VLA) to build on previous observations of this cluster.

    “This is a phenomenon that astronomers had been trying to find for a long time,” said Michael McDonald, astronomer at the Massachusetts Institute of Technology (MIT), who led the study. “This cluster demonstrates that, in some instances, the energetic output from a black hole can actually enhance cooling, leading to dramatic consequences.”

    The black hole is in the center of a galaxy cluster called the Phoenix Cluster, located about 5.8 billion light years from Earth in the Phoenix Constellation. The large galaxy hosting the black hole is surrounded by hot gas with temperatures of millions of degrees. The mass of this gas, equivalent to trillions of Suns, is several times greater than the combined mass of all the galaxies in the cluster.

    This hot gas loses energy as it glows in X-rays, which should cause it to cool until it can form large numbers of stars. However, in all other observed galaxy clusters, bursts of energy driven by such a black hole keep most of the hot gas from cooling, preventing widespread star birth.

    “Imagine running an air-conditioner in your house on a hot day, but then starting a wood fire. Your living room can’t properly cool down until you put out the fire,” said co-author Brian McNamara of the University of Waterloo in Canada. “Similarly, when a black hole’s heating ability is turned off in a galaxy cluster, the gas can then cool.”

    Evidence for rapid star formation in the Phoenix Cluster was previously reported in 2012 by a team led by McDonald. But deeper observations were required to learn details about the central black hole’s role in the rebirth of stars in the central galaxy, and how that might change in the future.

    By combining long observations in X-ray, optical, and radio light, the researchers gained a ten-fold improvement in the data quality compared to previous observations. The new Chandra data reveal that hot gas is cooling nearly at the rate expected in the absence of energy injected by a black hole. The new Hubble data show that about 10 billion solar masses of cool gas are located along filaments leading towards the black hole, and young stars are forming from this cool gas at a rate of about 500 solar masses per year. By comparison, stars are forming in the Milky Way galaxy at a rate of about one solar mass per year.

    The VLA radio data reveal jets blasting out from the vicinity of the central black hole. These jets likely inflated bubbles in the hot gas that are detected in the Chandra data. Both the jets and bubbles are evidence of past rapid growth of the black hole. Early in this growth, the black hole may have been undersized, compared to the mass of its host galaxy, which would allow rapid cooling to go unchecked.

    “In the past, outbursts from the undersized black hole may have simply been too weak to heat its surroundings, allowing hot gas to start cooling,” said co-author Matthew Bayliss, who was a researcher at MIT during this study, but has recently joined the faculty at the University of Cincinnati. “But as the black hole has grown more massive and more powerful, its influence has been increasing.”

    The cooling can continue when the gas is carried away from the center of the cluster by the black hole’s outbursts. At a greater distance from the heating influence of the black hole, the gas cools faster than it can fall back towards the center of the cluster. This scenario explains the observation that cool gas is located around the borders of the cavities, based on a comparison of the Chandra and Hubble data.

    Eventually the outburst will generate enough turbulence, sound waves and shock waves (similar to the sonic booms produced by supersonic aircraft) to provide sources of heat and prevent further cooling. This will continue until the outburst ceases and the build-up of cool gas can recommence. The whole cycle may then repeat.

    “These results show that the black hole has temporarily been assisting in the formation of stars, but when it strengthens its effects will start to mimic those of black holes in other clusters, stifling more star birth,” said co-author Mark Voit of Michigan State University in East Lansing, Michigan.

    The lack of similar objects shows that clusters and their enormous black holes pass through the rapid star formation phase relatively quickly.

    A paper describing these results was published in a recent issue of The Astrophysical Journal.


    A Quick Look at the Phoenix Cluster

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

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 9:37 am on November 8, 2019 Permalink | Reply
    Tags: "Chandra Archive Collection: Combing Through the 'X-ray Files'", , , , , NASA Chandra, X-ray images   

    From NASA Chandra: “Chandra Archive Collection: Combing Through the ‘X-ray Files'” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    October 30, 2019

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    A new collection of images is being released to recognize Archive month, which is celebrated every October in the US.

    These images contain X-rays from Chandra and optical light from the Hubble Space Telescope from data available in public archives.

    These new images include five supernova remnants and a region where stars are actively forming.

    The data taken by Chandra since 1999 are stored in a digital archive available to professional scientists and members of the public alike.

    In its 20 years of operations, NASA’s Chandra X-ray Observatory has observed hundreds of thousands of X-ray sources across the Universe. These data are stored in a public archive where anyone can access them a year after the observations, if not sooner.

    Most of the time, the Chandra archive serves the professional astronomical community for their research purposes, but its value extends far beyond. Some members of the public, including amateur astronomers and space enthusiasts, comb through astronomical archives like the one Chandra maintains. Their work has led to the discovery of new objects, investigations of mysterious phenomena, and the creation of stunning images of cosmic objects.

    A sample of composite images — that is, those that consist of more than one type of light — using X-ray data from Chandra and optical light from the Hubble Space Telescope is being released today. This image collection, made by “astronomy artist” Judy Schmidt, helps recognize Archive Month, which is celebrated every October in the United States and promotes the contributions of all types of archives. The software tools, instructions, and tutorials on how to make images from Chandra data are free and available in many locations online, including https://chandra.si.edu/photo/openFITS/

    All of the objects in this new archive collection are located in the Large Magellanic Cloud, or LMC, which is a small satellite galaxy to our Milky Way, located about 150,000 light years away. The images are:

    Top row, from left to right:

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    N103B
    When a thermonuclear explosion destroyed a white dwarf star (the dense final stage in the evolution of a Sun-like star) in a double star system and produced a supernova, it left behind this glowing debris field, called a supernova remnant. The Chandra X-ray data (most clearly visible on the left side of the remnant in red, green and blue) shows multimillion-degree gas that has been heated by a shock wave produced by the explosion that destroyed the star. An optical light image from the Hubble Space Telescope is brightest on the right side of the image, where the overlap with X-rays is mostly in pink and white.

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    LHA 120-N 44
    This region of star formation features a giant bubble that is blowing out from the middle of this image due to winds flowing off young stars. Chandra data (purple and pink) show this superbubble of hot gas, while Hubble data (orange and light blue) reveals the gas and dust in the system.

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    LMC N63A
    After a massive star exploded, it left behind this supernova remnant observed by Chandra and Hubble. The Chandra data (red, green and blue) show multimillion-degree gas and the blast wave from the supernova. The light brown region in the upper right of the remnant is a dense cloud of gas and dust that reflects optical light detected by Hubble.

    Bottom row, from left to right:

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    DEM L71
    The Chandra image of this supernova remnant (also known as SNR 0505.7-6752) reveals an inner cloud of glowing iron and silicon (green and blue) surrounded by an outer blast wave (red). The outer blast wave, created during the destruction of the white dwarf star, is also seen in optical data from Hubble (red and white).

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    SNR J0534.2-7033 (DEM L238)
    Another supernova remnant resulting from the explosion of a white dwarf star is revealed in this image of DEM L238, also known as SNR J0534.2-7033. The Chandra image (yellow, green and bright red) shows multimillion-degree gas and the Hubble image shows cooler gas in the system, near the outer border of the remnant in red.

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    N132D
    This is the brightest supernova remnant in either the LMC or its galactic cousin, the Small Magellanic Cloud. N132D also stands out because it belongs to a rare class of supernova remnants that have relatively high levels of oxygen. Scientists think most of the oxygen we breathe came from explosions similar to this one. Here, Chandra data are shown in purple and green and Hubble data are shown in red.

    For full images credits see the full article.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 2:43 pm on October 30, 2019 Permalink | Reply
    Tags: , , , Behind the Scenes with the Image Makers, , Judy Schmidt, Kim Arcand, Lisa Frattare, Nancy Wolk, NASA Chandra   

    From NASA Chandra: “Behind the Scenes with the Image Makers” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    2019-10-28

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    2019 Chandra Archive Collection Credit: Enhanced Image by Judy Schmidt (CC BY-NC-SA) based on
    images provided courtesy of NASA/CXC/SAO & NASA/STScI.

    It is both an art and a science to make images of objects from space. Most astronomical images are composed of light that humans cannot detect with their eyes. Instead, the data from telescopes like NASA’s Chandra X-ray Observatory are “translated,” so to speak, into a form that we can understand. This process is done following strict guidelines to ensure scientific accuracy while trying to achieve the highest levels of aesthetics possible.

    Over the two decades of the Chandra mission, we have had many talented people who have been involved with making our publicly-released images. We interviewed our current team and share some of their answers to questions posed to all of them below. Kim Arcand is Chandra’s visualization lead and has been with the mission since before launch; Nancy Wolk has been involved with Chandra’s data analysis, software, and spacecraft science operations before joining the image processing team; Lisa Frattare spent years making images from the Hubble Space Telescope before switching career gears but continues to lend her expertise part-time to Chandra’s efforts; Judy Schmidt is a citizen scientist who spends some of her free time using public data to make gorgeous images of space, including those featured in our latest release.

    How did you get involved in astronomy and/or astronomical images?

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    Nancy Wolk
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    Favorite image processed: NGC 6231

    Nancy Wolk: I’ve always wanted to be an astronomer. I studied astronomy and physics in college and completed a Master’s degree in astronomy. After graduation, I moved to the Boston area and started working with data analysis with the Chandra X-ray Observatory (then called AXAF). Over the years, I moved from data analysis to software and then space craft science operations. I’ve been able to talk directly with the observers and help them configure the instruments for them. Most recently, I have been working with preparing images for press releases.

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    Kim Arcand
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    Favorite image processed: Tycho’s Supernova Remnant

    Kim Arcand: I completed my undergraduate work in molecular biology. My interests then were on bacteria and disease, so I was looking at things like Ixodes Scapularis (the Deer tick) and the spirochaetes that can be transmitted to humans which can cause Lyme Disease. But as I neared the end of my degree I found that I was more attracted to the computer as a tool to tell stories about science than I was to any bugs or bacteria. (The physics and chemistry courses I had to take for that degree, however, would become incredibly useful in my later work.) I moved into a computer science graduate program after completing a degree in biology, and the programming/coding/application development of that was a key tool in my future work with Chandra. I would say it was really the mix of science and computer science that helped move me into astronomical data visualization and related projects.

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    Judy Schmidt
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    Favorite image processed: Chamaeleon

    Judy Schmidt: I’ve long been interested in astronomy, but what got me hooked on image processing was the European Space Agency (ESA) Hubble’s Hidden Treasure contest in 2012. Prior to that, I had no idea that data from NASA’s Great Observatories are publicly available for anyone in the world to work with. I always wanted to try some astronomical image processing, but I thought I had to buy my own telescope, travel to some dark skies, and capture my own data. Discovering the vast public archives full of professional data changed my life from merely being a casual onlooker to actively participating in a meaningful way within the astronomy community, and I love it.

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    Lisa Frattare
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    Favorite image processed: Butterfly Nebula

    Lisa Frattare: I have a Master’s in astronomy from Wesleyan University. That landed me working as a data analyst and later, an image processor for the Hubble Space Telescope at Space Telescope Science Institute (STScI) in Baltimore, MD. I worked on the Hubble Project as a member of the news team and Hubble Heritage Project. My main role was to help astronomers make their scientific data into exciting images that would appeal to fellow scientists and the public alike. During my 20-year tenure at STScI, I worked on over 300 Hubble images, observed with the telescope, worked on 3D imaging of several targets which led to two IMAX films, and did a small stint on processing X-ray data for the Chandra X-ray Observatory. I now work directly with the Chandra news and outreach group. Although X-rays look different than optical data, the mechanism of X-ray data processing is the same. Once again, I convert scientific data into an image that is sometimes rendered as just the X-ray data, and other times it is composited with other wavelengths like optical, infrared and radio.

    Do you think working with these images requires particular skills or interests?

    Kim Arcand: Being curious about a topic seems to get us pretty far in my group. I would say that curiosity is the most important “skill” in working with data like this. The technical aspects can fall into place with a bit of work, but without that first breath of curiosity, I don’t know how rewarding or interesting it would be for someone. That said, the technical skills are certainly useful to have, though there are a range of different software applications and scripting languages that can help depending on what part of the pipeline of image processing someone is interested in. Some of the astronomical packages like ds9/js9/SAO Image are a good place to start. And Photoshop plus FitsLiberator are an “industry standard.” It certainly never hurts to have coding skills in this area, but I also can’t overstate the usefulness of having an overall aesthetic or “eye” for art as well.

    Judy Schmidt: I don’t think there is “One True Way,” but a strong familiarity with some kind of digital photo editing software, such as Photoshop, and an understanding of color theory are both essential. My background is in multimedia design, so the astronomy side of things is largely self-taught. This is probably not ideal, but I’ve managed to make it work. There are a lot of resources available online that I am grateful for, and I have been lucky to sometimes receive some helpful tips directly from professionals. I am also privileged enough in life to have a substantial amount of time available to devote to this hobby.

    Lisa Frattare: I don’t think there is a single cookie cutter astronomical image processor. Each of us comes to the role with a different level of interest in science, color, patterns, analytical data, photography, astronomical knowledge, experience, academic training, etc. Part of the equation includes trying something new, putting in the time and effort, and knowing when to stop fussing with an image.

    Nancy Wolk: I do find that you need a basic understanding of astronomy and how astronomical images are created. Many times, the images are not projected onto a flat surface, which means you need to be careful doing measurements along the areas with the largest changes from flat. Each telescope is different and aligning the images can be difficult at times. In addition, knowing the physics behind the particular image is important to understanding what you want to emphasize. Basic art skills such as understanding color theory helps as well to choose colors that really make the images catch the public’s eye.

    Do you think astronomical images resonate with the public in different ways than those from other types of science? If so, why?

    Judy Schmidt: Absolutely. Humans have long known that there is something bigger than us out there, and different cultures have so many different stories and metaphors to tell about it, but astronomical images bring us directly in touch with that feeling. It’s like making a connection to some secret hidden truth that perhaps we were never worthy of, but the Universe whispered it to us anyway. There’s just something special about receiving a message that’s thousands, millions, or even billions of years old. And in many cases, it takes little or no special understanding to not only appreciate it, but yearn for more.

    Lisa Frattare: There is a feeling of discovery and a sense of wonder that comes from how astronomical images are perceived. From our early photographs of the Moon, to overexposed black and white spirals and ellipticals from early ground-based telescopes, humans have loved viewing and pondering the heavens.

    Kim Arcand: I’m a little bit biased here because I come from a place where microscopic images were my first love, and I would like to say they resonate out in the public sphere quite well. I’m also rather loyal to the telescopic images because … well, they’re awesome. So I love the micro and the macro when it comes to imagery. It certainly seems, however (in a non-scientifically assessed way), that the Universe gets more than its fair share of attention with experts and non-experts, and is definitely out in the pop culture world. I’ve found images I or my team have worked on in all sorts of corners of the world, from earrings on Etsy to high-fashion dresses, from album covers to bed covers, in non-astronomy movies and TV/streaming series. It’s always a surprise and a joy to see our data being used in such a way. There’s never enough science imagery for my tastes, but there seems to be a particular appeal to images of the Universe. Perhaps because they seem to hint at answers to those huge questions of where do we come from, who are we, and where are we going?

    Nancy Wolk: Many people have a very tenuous relationship with our sky. Living in major cities, many people only see the brightest stars. Bringing people astronomical images really brings the Universe to the people. When we can show images of planets and then some of the more exotic phenomenon in space, we’re opening doors of possibility.

    Do you have any advice for anyone who is interested in using astronomical data in public archives for image making or other pursuits?
    Lisa Frattare: Observational astronomy is a rocking field. Much of the software needed to analyze telescope data is user friendly and meant to be accessed from anywhere. The NASA Great Observatories Chandra, Hubble and Spitzer, put their data in public online archives. Anyone with a computer and a passion can learn how to process images from the archival data to make incredible pictures of the cosmos. There is also a supportive group of interested, non-professional image processors who share and learn from each other.

    Nancy Wolk: I’ve recently had the privilege of working with a young college student in India this past year. We’ve discussed different ways to process X-ray data so that data are both accurate and pretty. He’s asked many questions and I can see how his work has come a long way. I recommend reaching out to the outreach offices at telescopes. That’s why we are here. We want to help people hone their skills and learn how to mix the different wavelengths to gain a better understanding of our universe.

    Judy Schmidt: Try not to feel intimidated. I used to worry someone would jump in and tell me I was doing everything wrong and bad, but that never happened. Learning the jargon and getting past the technical parts is worth it. Not a whole lot of people do this work, and there’s no secret club, so try to find us on Twitter or other social networks. I’ve helped a lot of beginners who have asked me questions through email, Twitter, and elsewhere.

    Kim Arcand: There are so many different ways to try your hand at imaging the Universe. Here is a brief guide of resources we’ve created or partnered on:

    Brand new to this? Start out by learning how computers use red, green and blue to add color to digital images, and try coloring some real NASA data sets at https://chandra.si.edu/code.

    Next, try watching this TEDx talk to get a brief introduction to what we do at Chandra to visualize the high-energy Universe (https://www.youtube.com/watch?v=8kTMr5LqIBQ). Head over to Vox for a more indepth video on how we color the Universe in different kinds of light (https://www.youtube.com/watch?v=WSG0MnmUsEY).

    A good next step would be to take an image using the MicroObservatory (https://mo-www.cfa.harvard.edu/MicroObservatory/), where you can even submit an image for their NASA data photo challenges. There are a number of good resources to try in here.

    After that, a trip through our Open Fits tutorials (https://chandra.si.edu/photo/openFITS/) might be a good place to go. “FITS”, which stands for Flexible Image Transport System, is a digital file format used mainly by astronomers. In this section you can download FITS files for some of our favorite Chandra images and learn how to compose your own versions of these high-energy astronomy images with a series of short tutorials.

    When you’re ready, dive in to the NASA archives! Each NASA mission has a wealth of data to dig through, and such data is typically public about a year after it’s been taken. For Chandra, there are about 19 years of X-ray data to comb through for treasures (http://cxc.harvard.edu/cda/). For Hubble, there’s about 28 years of data (https://archive.stsci.edu/hst/). And that’s just two astronomical missions. All are publicly accessible, ready to be shined up and polished into a gorgeous visual treat.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 12:34 pm on October 28, 2019 Permalink | Reply
    Tags: "Chandra Spots a Mega-Cluster of Galaxies in the Making", A mega-merger of four galaxy clusters in Abell 1758 has been observed by Chandra and other telescopes., , , , , NASA Chandra   

    From NASA Chandra: “Chandra Spots a Mega-Cluster of Galaxies in the Making” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    October 24, 2019

    1
    Composite

    2
    X-ray

    3
    Optical

    A mega-merger of four galaxy clusters in Abell 1758 has been observed by Chandra and other telescopes.

    Abell 1758 contains two pairs of galaxy clusters, each with hundreds of galaxies embedded in large amounts of hot gas and unseen dark matter.

    Eventually these two pairs of clusters will collide to form one of the most massive objects in the Universe.

    The X-rays from Chandra helped astronomers estimate how fast one pair of clusters were moving toward each other.

    Astronomers using data from NASA’s Chandra X-ray Observatory and other telescopes have put together a detailed map of a rare collision between four galaxy clusters. Eventually all four clusters — each with a mass of at least several hundred trillion times that of the Sun — will merge to form one of the most massive objects in the universe.

    Galaxy clusters are the largest structures in the cosmos that are held together by gravity. Clusters consist of hundreds or even thousands of galaxies embedded in hot gas, and contain an even larger amount of invisible dark matter. Sometimes two galaxy clusters collide, as in the case of the Bullet Cluster, and occasionally more than two will collide at the same time.

    The new observations show a mega-structure being assembled in a system called Abell 1758, located about 3 billion light-years from Earth. It contains two pairs of colliding galaxy clusters that are heading toward one another. Scientists first recognized Abell 1758 as a quadruple galaxy cluster system in 2004 using data from Chandra and XMM-Newton, a satellite operated by the European Space Agency (ESA).

    ESA/XMM Newton

    Each pair in the system contains two galaxy clusters that are well on their way to merging. In the northern (top) pair seen in the composite image, the centers of each cluster have already passed by each other once, about 300 to 400 million years ago, and will eventually swing back around. The southern pair at the bottom of the image has two clusters that are close to approaching each other for the first time.

    2
    Labeled image of Abell 1758 system.

    X-rays from Chandra are shown as blue and white, depicting fainter and brighter diffuse emission, respectively. This new composite image also includes an optical image from the Sloan Digital Sky Survey.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft)

    The Chandra data revealed for the first time a shock wave — similar to the sonic boom from a supersonic aircraft — in hot gas visible with Chandra in the northern pair’s collision. From this shock wave, researchers estimate two clusters are moving about 2 million to 3 million miles per hour (3 million to 5 million kilometers per hour), relative to each other.

    Chandra data also provide information about how elements heavier than helium, the “heavy elements,” in galaxy clusters get mixed up and redistributed after the clusters collide and merge. Because this process depends on how far a merger has progressed, Abell 1758 offers a valuable case study, since the northern and the southern pairs of clusters are at different stages of merging.

    In the southern pair, the heavy elements are most abundant in the centers of the two colliding clusters, showing that the original location of the elements has not been strongly impacted by the ongoing collision. By contrast, in the northern pair, where the collision and merger has progressed further, the location of the heavy elements has been strongly influenced by the collision. The highest abundances are found between the two cluster centers and to the left side of the cluster pair, while the lowest abundances are in the center of the cluster on the left side of the image.

    Collisions between clusters affect their component galaxies as well as the hot gas that surrounds them. Data from the 6.5-meter MMT telescope in Arizona, obtained as part of the Arizona Cluster Redshift Survey, show that some galaxies are moving much faster than others, probably because they have been thrown away from the other galaxies in their cluster by gravitational forces imparted by the collision.

    CfA U Arizona Fred Lawrence Whipple Observatory Steward Observatory MMT Telescope at the summit of Mount Hopkins near Tucson, Arizona, USA, Altitude 2,616 m (8,583 ft)

    The team also used radio data from the Giant Metrewave Radio Telescope (GMRT), and X-ray data from ESA’s XMM-Newton mission.

    Giant Metrewave Radio Telescope, an array of thirty telecopes, located near Pune in India

    A paper describing these latest results by Gerrit Schellenberger, Larry David, Ewan O’Sullivan, Jan Vrtilek (all from Center for Astrophysics | Harvard & Smithsonian) and Christopher Haines (Universidad de Atacama, Chile) was published in the September 1st, 2019 issue of The Astrophysical Journal.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 5:08 pm on October 17, 2019 Permalink | Reply
    Tags: "The Clumpy and Lumpy Death of a Star", , , , , NASA Chandra, The Tycho supernova remnant   

    From NASA Chandra: “The Clumpy and Lumpy Death of a Star” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    October 17, 2019

    1
    Composite

    2
    X-ray

    3
    Optical

    A new image of the Tycho supernova remnant from Chanda shows a pattern of bright clumps and fainter holes in the X-ray data.

    Scientists are trying to determine if this ‘clumpiness’ was caused by the supernova explosion itself or something in its aftermath.

    By comparing Chandra data to computer simulations, researchers found evidence that the explosion was likely the source of this lumpy distribution.

    The original supernova was first seen by skywatchers in 1572, including the Danish astronomer Tycho Brahe who the object was eventually named after.

    In 1572, Danish astronomer Tycho Brahe was among those who noticed a new bright object in the constellation Cassiopeia. Adding fuel to the intellectual fire that Copernicus started, Tycho showed this “new star” was far beyond the Moon, and that it was possible for the Universe beyond the Sun and planets to change.

    Astronomers now know that Tycho’s new star was not new at all. Rather it signaled the death of a star in a supernova, an explosion so bright that it can outshine the light from an entire galaxy. This particular supernova was a Type Ia, which occurs when a white dwarf star pulls material from, or merges with, a nearby companion star until a violent explosion is triggered. The white dwarf star is obliterated, sending its debris hurtling into space.

    As with many supernova remnants, the Tycho supernova remnant, as it’s known today (or “Tycho,” for short), glows brightly in X-ray light because shock waves — similar to sonic booms from supersonic aircraft — generated by the stellar explosion heat the stellar debris up to millions of degrees. In its two decades of operation, NASA’s Chandra X-ray Observatory has captured unparalleled X-ray images of many supernova remnants.

    Chandra reveals an intriguing pattern of bright clumps and fainter areas in Tycho. What caused this thicket of knots in the aftermath of this explosion? Did the explosion itself cause this clumpiness, or was it something that happened afterward?

    This latest image of Tycho from Chandra is providing clues. To emphasize the clumps in the image and the three-dimensional nature of Tycho, scientists selected two narrow ranges of X-ray energies to isolate material (silicon, colored red) moving away from Earth, and moving towards us (also silicon, colored blue). The other colors in the image (yellow, green, blue-green, orange and purple) show a broad range of different energies and elements, and a mixture of directions of motion. In this new composite image, Chandra’s X-ray data have been combined with an optical image of the stars in the same field of view from the Digitized Sky Survey.

    By comparing the Chandra image of Tycho to two different computer simulations, researchers were able to test their ideas against actual data. One of the simulations began with clumpy debris from the explosion. The other started with smooth debris from the explosion and then the clumpiness appeared afterwards as the supernova remnant evolved and tiny irregularities were magnified.

    A statistical analysis using a technique that is sensitive to the number and size of clumps and holes in images was then used. Comparing results for the Chandra and simulated images, scientists found that the Tycho supernova remnant strongly resembles a scenario in which the clumps came from the explosion itself. While scientists are not sure how, one possibility is that star’s explosion had multiple ignition points, like dynamite sticks being set off simultaneously in different locations.

    Understanding the details of how these stars explode is important because it may improve the reliability of the use of Type Ia supernovas “standard candles” — that is, objects with known inherent brightness, which scientists can use to determine their distance. This is very important for studying the expansion of the universe. These supernovae also sprinkle elements such as iron and silicon, that are essential for life as we know it, into the next generation of stars and planets.

    A paper describing these results appeared in the July 10th, 2019 issue of The Astrophysical Journal. The authors are Toshiki Sato (RIKEN in Saitama, Japan, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland), John (Jack) Hughes (Rutgers University in Piscataway, New Jersey), Brian Williams, (NASA’s Goddard Space Flight Center), and Mikio Morii (The Institute of Statistical Mathematics in Tokyo, Japan).

    4
    3D printed model of Tycho’s Supernova Remnant

    Another team of astronomers, led by Gilles Ferrand of RIKEN in Saitama, Japan, has constructed their own three-dimensional computer models of a Type Ia supernova remnant as it changes with time. Their work shows that initial asymmetries in the simulated supernova explosion are required so that the model of the ensuing supernova remnant closely resembles the Chandra image of Tycho, at a similar age. This conclusion is similar to that made by Sato and his team.

    A paper describing the results by Ferrand and co-authors appeared in the June 1st, 2019 issue of The Astrophysical Journal.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    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.

     
  • richardmitnick 5:11 pm on September 11, 2019 Permalink | Reply
    Tags: "Scientists Discover Black Hole Has Three Hot Meals a Day", , , , , NASA Chandra, The black hole at the center of the galaxy called GSN 069   

    From NASA Chandra: “Scientists Discover Black Hole Has Three Hot Meals a Day” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    September 11, 2019
    From Chandra at CfA
    Megan Watzke
    Chandra X-ray Center, Cambridge, Mass.
    617-496-7998
    mwatzke@cfa.harvard.edu

    From ESA

    Giovanni Miniutti
    Centro de Astrobiología (CAB, CSIC-INTA)
    Madrid, Spain
    Email: gminiutti@cab.inta-csic.es

    Richard Saxton
    Telespazio-Vega UK for ESA
    XMM-Newton Science Operations Centre
    European Space Agency
    Email: richard.saxton@sciops.esa.int

    Margherita Giustini
    Centro de Astrobiología (CAB, CSIC-INTA)
    Madrid, Spain
    Email: mgiustini@cab.inta-csic.es

    Norbert Schartel
    XMM-Newton project scientist
    European Space Agency
    Email: norbert.schartel@sciops.esa.int

    1
    X-ray: NASA/CXO/CSIC-INTA/G.Miniutti et al.; Optical: DSS

    Evidence for a supermassive black hole consuming large amounts of material about three times a day has been found.

    The data come from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton taken over the span of 54 days beginning in late 2018.

    The orbiting X-ray telescopes detected regular outbursts from the black hole at the center of the galaxy called GSN 069.

    Astronomers estimate that each “meal” contains the mass about four times that of the Moon.

    There’s an adage that it’s not healthy to skip meals. Apparently, a supermassive black hole in the center of a galaxy millions of light years away has gotten the message.

    A team of astronomers found X-ray bursts repeating about every nine hours originating from the center of a galaxy called GSN 069. Obtained with NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM-Newton, these data indicate that the supermassive black hole located there is consuming large amounts of material on a regular schedule.

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    XMM-Newton observations

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    Quasi-periodic eruptions in GSN 069

    ESA/XMM Newton

    While scientists had previously found two “stellar-mass” black holes (that weigh about 10 times the Sun’s mass) occasionally undergoing regular outbursts before, this behavior has never been detected from a supermassive black hole until now.

    The black hole at the center of GSN 069, located 250 million light years from Earth, contains about 400,000 times the mass of the Sun. The researchers estimate that the black hole is consuming about four Moons’ worth of material about three times a day. That’s equivalent to almost a million billion billion pounds going into the black hole per feeding.

    “This black hole is on a meal plan like we’ve never seen before,” said Giovanni Miniutti from ESA’s Center for Astrobiology in Spain, the first author of a Nature paper, published today in the September 11, 2019 issue of the journal, describing these results. “This behavior is so unprecedented that we had to coin a new expression to describe it: “X-ray Quasi-Periodic Eruptions”.”

    ESA’s XMM-Newton was the first to observe this phenomenon in GSN 069 with the detection of two bursts on December 24, 2018. Miniutti and colleagues then followed up with more XMM-Newton observations on January 16 and 17, 2019, and found five outbursts. Observations by Chandra less than a month later, on February 14, revealed an additional three outbursts.

    “By combining data from these two X-ray observatories, we have tracked these periodic outbursts for at least 54 days” said co-author Richard Saxton of the European Space Astronomy Centre in Madrid, Spain. “This gives us a unique opportunity to witness the flow of matter into a supermassive black hole repeatedly speeding up and slowing down.”

    During the outbursts the X-ray emission becomes about 20 times brighter than during the quiet times. The temperature of gas falling towards the black hole also climbs, from about one million degrees Fahrenheit during the quiet periods to about 2.5 million degrees Fahrenheit during the outbursts. The temperature of the latter is similar to that of gas found around most actively growing supermassive black holes.

    The origin of this hot gas has been a long-standing mystery because it appears to be too hot to be associated with the disk of infalling matter surrounding the black holes. Although its origin is also a mystery in GSN 069, the ability to study a supermassive black hole where hot gas repeatedly forms then disappears may provide important clues.

    “We think the origin of the X-ray emission is a star that the black hole has partially or completely torn apart and is slowly consuming bit by bit.” said co-author Margherita Giustini, also of ESA’s Center for Astrobiology. “But as for the repeating bursts, this is a completely different story whose origin needs to be studied with further data and new theoretical models”.

    The consumption of gas from a disrupted star by a supermassive black hole has been observed before, but never accompanied by repetitive X-ray bursts. The authors suggest there are two possible explanations for the bursts. One is that the amount of energy in the disk builds up until it becomes unstable and matter rapidly falls into the black hole producing the bursts. The cycle would then repeat. Another is that there is an interaction between the disk and a secondary body orbiting the black hole, perhaps the remnant of the partially disrupted star.

    The Chandra data were crucial for this study because they were able to show that the X-ray source is located in the center of the host galaxy, which is where a supermassive black hole is expected to be. The combination of data from Chandra and XMM-Newton implies that the size and duration of the black hole’s meals have decreased slightly, and the gap between the meals has increased. Future observations will be crucial to see if the trend continues.

    Supermassive black holes are usually larger than GSN 069, with masses of millions or even billions of suns. The larger the black hole the slower their fluctuations in brightness will be, so instead of erupting every nine hours they should erupt every few months or years which likely explains why quasi-periodic eruptions where never seen before.

    Examples of large increases or decreases in the amount of X-rays produced by black holes have been observed in a few cases, using repeated observations over months or even years. The changes in some objects are much faster than expected by standard theory of disks of infalling matter surrounding black holes, but could be naturally accounted for if they were experiencing similar behavior to GSN 069.

    Along with data from Chandra and XMM-Newton the international research team used data from NASA’s Swift X-ray observatory, the NASA/ESA Hubble Space Telescope, NRAO’s Karl G. Jansky Very Large Array in New Mexico, USA, CSIRO’s Australia Telescope Compact Array in Australia, and SARAO’s MeerKAT radio telescope in South Africa.

    NASA Neil Gehrels Swift Observatory

    NASA/ESA Hubble Telescope

    NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

    CSIRO Australia Compact Array, six radio telescopes at the Paul Wild Observatory, is an array of six 22-m antennas located about twenty five kilometres (16 mi) west of the town of Narrabri in Australia.

    SKA Meerkat telescope(s), 90 km outside the small Northern Cape town of Carnarvon, SA

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
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