Tagged: NASA Chandra Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 12:38 pm on September 3, 2020 Permalink | Reply
    Tags: "Chandra Opens Treasure Trove of Cosmic Delights", , , , , NASA Chandra   

    From NASA Chandra: “Chandra Opens Treasure Trove of Cosmic Delights” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    September 2, 2020

    1

    A new montage of images showcases the combination of data from telescopes that collect different kinds of light.

    The “multiwavelength” approach to astronomy is crucial to getting a complete understanding of objects in space.

    NASA’s Chandra X-ray Observatory provides the X-ray view of the objects in this collection.

    Two galaxies, a galaxy cluster, supernova remnant, double star system, and planetary nebula are represented.

    Humanity has “eyes” that can detect all different types of light through telescopes around the globe and a fleet of observatories in space. From radio waves to gamma rays, this “multiwavelength” approach to astronomy is crucial to getting a complete understanding of objects in space.

    This compilation gives examples of images from different missions and telescopes being combined to better understand the science of the universe. Each of these images contains data from NASA’s Chandra X-ray Observatory as well as other telescopes. Various types of objects are shown (galaxies, supernova remnants, stars, planetary nebulas), but together they demonstrate the possibilities when data from across the electromagnetic spectrum are assembled.

    Top row, from left to right:

    Messier 82
    Messier 82 is a galaxy that is oriented edge-on to Earth. This gives astronomers and their telescopes an interesting view of what happens as this galaxy undergoes bursts of star formation. X-rays from Chandra (appearing as blue and pink) show gas in outflows about 20,000 light years long that has been heated to temperatures above ten million degrees by repeated supernova explosions. Optical light data from NASA’s Hubble Space Telescope (red and orange) shows the galaxy.

    Abell 2744
    Galaxy clusters are the largest objects in the universe held together by gravity. They contain enormous amounts of superheated gas, with temperatures of tens of millions of degrees, which glows brightly in X-rays, and can be observed across millions of light years between the galaxies. This image of the Abell 2744 galaxy cluster combines X-rays from Chandra (diffuse blue emission) with optical light data from Hubble (red, green, and blue).

    Supernova 1987A (SN 1987A)
    On February 24, 1987, observers in the southern hemisphere saw a new object in a nearby galaxy called the Large Magellanic Cloud. This was one of the brightest supernova explosions in centuries and soon became known as Supernova 1987A (SN 87A). The Chandra data (blue) show the location of the supernova’s shock wave — similar to the sonic boom from a supersonic plane — interacting with the surrounding material about four light years from the original explosion point. Optical data from Hubble (orange and red) also shows evidence for this interaction in the ring.

    Bottom row, from left to right:

    Eta Carinae
    What will be the next star in our Milky Way galaxy to explode as a supernova? Astronomers aren’t certain, but one candidate is in Eta Carinae, a volatile system containing two massive stars that closely orbit each other. This image has three types of light: optical data from Hubble (appearing as white), ultraviolet (cyan) from Hubble, and X-rays from Chandra (appearing as purple emission). The previous eruptions of this star have resulted in a ring of hot, X-ray emitting gas about 2.3 light years in diameter surrounding these two stars.

    Cartwheel Galaxy
    This galaxy resembles a bull’s eye, which is appropriate because its appearance is partly due to a smaller galaxy that passed through the middle of this object. The violent collision produced shock waves that swept through the galaxy and triggered large amounts of star formation. X-rays from Chandra (purple) show disturbed hot gas initially hosted by the Cartwheel galaxy being dragged over more than 150,000 light years by the collision. Optical data from Hubble (red, green, and blue) show where this collision may have triggered the star formation.

    Helix Nebula
    When a star like the Sun runs out of fuel, it expands and its outer layers puff off, and then the core of the star shrinks. This phase is known as a “planetary nebula,” and astronomers expect our Sun will experience this in about 5 billion years. This Helix Nebula images contains infrared data from NASA’s Spitzer Space Telescope (green and red), optical light from Hubble (orange and blue), ultraviolet from NASA’s Galaxy Evolution Explorer (cyan), and Chandra’s X-rays (appearing as white) showing the white dwarf star that formed in the center of the nebula. The image is about four light years across.

    Three of these images — SN 1987A, Eta Carinae, and the Helix Nebula — were developed as part of NASA’s Universe of Learning (UoL), an integrated astrophysics learning and literacy program, and specifically UoL’s ViewSpace project. The UoL brings together experts who work on Chandra, the Hubble Space Telescope, Spitzer Space Telescope, and other NASA astrophysics missions.

    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 3:49 pm on August 19, 2020 Permalink | Reply
    Tags: "Kepler's Supernova Remnant: Debris from Stellar Explosion Not Slowed After 400 Years", , , , , NASA Chandra   

    From NASA Chandra: “Kepler’s Supernova Remnant: Debris from Stellar Explosion Not Slowed After 400 Years” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    August 19, 2020

    A new series of Chandra images shows pieces of Kepler’s supernova remnant are moving up to 23 million miles an hour.

    These are extremely high speeds for an explosion that happened over 400 years ago as seen from Earth.

    Researchers used a Chandra spectrum and images obtained in 2000, 2004, 2006 and 2014 to measure the speeds of knots in the remnant.

    Kepler is a so-called Type Ia supernova, the thermonuclear explosion of a white dwarf star.

    1
    Kepler Type Ia supernova remnant. NASA.

    Astronomers have used NASA’s Chandra X-ray Observatory to record material blasting away from the site of an exploded star at speeds faster than 20 million miles per hour. This is about 25,000 times faster than the speed of sound on Earth.

    Kepler’s supernova remnant is the debris from a detonated star that is located about 20,000 light years away from Earth in our Milky Way galaxy. In 1604 early astronomers, including Johannes Kepler who became the object’s namesake, saw the supernova explosion that destroyed the star.

    We now know that Kepler’s supernova remnant is the aftermath of a so-called Type Ia supernova, where a small dense star, known as a white dwarf, exceeds a critical mass limit after interacting with a companion star and undergoes a thermonuclear explosion that shatters the white dwarf and launches its remains outward.

    The latest study tracked the speed of 15 small “knots” of debris in Kepler’s supernova remnant, all glowing in X-rays, all glowing in X-rays. The fastest knot was measured to have a speed of 23 million miles per hour, the highest speed ever detected of supernova remnant debris in X-rays. The average speed of the knots is about 10 million miles per hour, and the blast wave is expanding at about 15 million miles per hour. These results independently confirm the 2017 discovery of knots travelling at speeds more than 20 million miles per hour in Kepler’s supernova remnant.

    Researchers in the latest study estimated the speeds of the knots by analyzing Chandra X-ray spectra, which give the intensity of X-rays at different wavelengths, obtained in 2016. By comparing the wavelengths of features in the X-ray spectrum with laboratory values and using the Doppler effect, they measured the speed of each knot along the line of sight from Chandra to the remnant. They also used Chandra images obtained in 2000, 2004, 2006 and 2014 to detect changes in position of the knots and measure their speed perpendicular to our line of sight. These two measurements combined to give an estimate of each knot’s true speed in three-dimensional space. A graphic gives a visual explanation for how motions of knots in the images and the X-ray spectra were combined to estimate the total speeds.

    The 2017 work applied the same general technique as the new study, but used X-ray spectra from a different instrument on Chandra. This meant the new study had more precise determinations of the knot’s speeds along the line of sight and, therefore, the total speeds in all directions.

    In this new sequence of the four Chandra images of Kepler’s supernova remnant, red, green, and blue reveal the low, medium, and high-energy X-rays respectively. The movie zooms in to show several of the fastest moving knots.

    The high speeds in Kepler are similar to those scientists have seen in optical observations of supernova explosions in other galaxies only days or weeks after the explosion, well before a supernova remnant forms decades later. This comparison implies that some knots in Kepler have hardly been slowed down by collisions with material surrounding the remnant in the approximately 400 years since the explosion.

    Based on the Chandra spectra, eight of the 15 knots are definitely moving away from Earth, but only two are confirmed to be moving towards it. (The other five do not show a clear direction of motion along our line of sight.) This asymmetry in the motion of the knots implies that the debris may not be symmetric along our line of sight, but more knots need to be studied to confirm this result.

    The four knots with the highest total speeds are all located along a horizontal band of bright X-ray emission. Three of them are labeled in a close-up view. These four knots are all moving in a similar direction and have similar amounts of elements such as silicon, suggesting that the matter in all of these knots originated from the same layer of the exploded white dwarf.

    One of the other fastest moving knots is located in the “ear” of the right side of the remnant, supporting the intriguing idea that the three-dimensional shape of the debris is more like a football than a uniform sphere. This knot and two others are labeled with arrows in a close-up view.

    The explanation for the high-speed material is unclear. Some scientists have suggested that Kepler’s supernova remnant is from an unusually powerful Type Ia, which might explain the fast-moving material. It is also possible that the immediate environment around the remnant is itself clumpy, which could allow some of the debris to tunnel through regions of low density and avoid being decelerated very much.

    The 2017 team also used their data to refine previous estimates of the location of the supernova explosion. This allowed them to search for a companion to the white dwarf that may have been left behind after the supernova, and learn more about what triggered the explosion. They found a lack of bright stars near the center of the remnant. This implied that a star like the Sun did not donate material to the white dwarf until it reached critical mass. A merger between two white dwarfs is favored instead.

    The new results have been reported in a paper led by Matthew Millard, from the University of Texas at Arlington, and published in the April 20th, 2020 issue of The Astrophysical Journal.The co-authors of the paper are Jayant Bhalerao and Sangwook Park (University of Texas at Arlington), 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), Patrick Slane and Daniel Patnaude (Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.), David Burrows (Penn State University, University Park, Penn.), and Carles Badenes (University of Pittsburgh, Penn).

    A paper by Toshiki Sato and Jack Hughes reported the discovery of fast-moving knots in Kepler’s supernova remnant and was published in the August 20th, 2017 issue of The Astrophysical Journal.

    The X-ray spectra used by Millard and collaborators were obtained with the Chandra High Energy Transmission Grating.

    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 4:48 pm on August 3, 2020 Permalink | Reply
    Tags: "SpARCS1049: Black Hole Fails to Do Its Job", , , , , NASA Chandra   

    From NASA Chandra: “SpARCS1049: Black Hole Fails to Do Its Job” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    8.3.20

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

    1
    Composite

    2
    X-ray

    3
    Optical/IR

    A new study reveals what happens when a supermassive black hole in the center of a galaxy cluster stops being active.

    By combining data from Chandra, Hubble, and Spitzer data, astronomers found a deluge of star formation in the cluster known as SpARCS1049.

    SpARCS1049 is producing stars at a rate some 300 times that seen in the Milky Way galaxy.

    This result is in contrast with many other clusters that show how active supermassive black holes keep gas too hot to form many stars.

    A galaxy cluster is demonstrating what can happen when a supermassive black hole stops being active, as described in our latest press release [N/A]. SpARCS104922.6+564032.5 (SpARCS1049 for short) is a galaxy cluster located 9.9 billion light years away from Earth. Galaxy clusters contain hundreds or thousands of galaxies pervaded by hot, X-ray emitting gas that outweighs the combined mass of all the galaxies. In this image of SpARCS1049, X-rays from NASA’s Chandra X-ray Observatory (light blue) have been combined with optical and infrared light data from NASA’s Hubble Space Telescope (red, green, and blue).

    Astronomers have seen many examples where a supermassive black hole in a cluster’s central galaxy prevents this hot gas from cooling to form vast numbers of stars. This heating allows supermassive black holes to influence or control the activity and evolution of their host cluster.

    However, the would-be domineering black hole in SpARCS1049 is behaving differently and is almost completely dormant. This appears to be allowing star formation to run rampant. According to observations from Hubble and NASA’s Spitzer Space Telescope, SpARCS1049 is forming stars at a rate over 300 times our Milky Way galaxy. (At this rate of SpARCS1049, all of the stars in the Milky Way could form in just 100 million years, which is one percent of our Galaxy’s age of more than 10 billion years.)

    Researchers tried to determine what is causing this explosion of star formation and why it is located about 80,000 light years away from the center of SpARCS1049, outside any of the cluster’s galaxies. The Chandra data show that the temperature of the gas in the site of prodigious star formation has cooled to about 10 million degrees. (This is in contrast to most of the rest of the cluster where the gas is hotter at about 65 million degrees.) The presence of this cooler gas suggests that other undetected gas reservoirs have cooled to even lower temperatures that enable huge numbers of stars to form.

    An annotated version of the composite image shows the location of the densest hot gas seen with Chandra, along with the galaxy in the center of the cluster. The coolest gas detected by Chandra and the site of the most rapid star formation is located halfway between the densest gas and the central galaxy.

    4
    Close-Up Composite Image, Labeled (Credit: X-ray: NASA/CXO/Univ. of Montreal/J. Hlavacek-Larrondo et al; Optical/IR: NASA/STScI)

    Astronomers do not see any signs that a supermassive black hole in the central galaxy is actively pulling in matter in SpARCS1049. For example, they do not find any evidence for a jet of material blowing away from the black hole at radio wavelengths, or of an X-ray source from the middle of the galaxy indicating that matter was heated as it fell towards a black hole. These are the common signs that a black hole is growing quickly and keeping the gas of a cluster too warm to form many stars. These black holes, however, are typically found in galaxy clusters that are only a few hundred million light years from Earth and are much older than SpARCS1049. This could mean that black holes in younger and more distant galaxy clusters act differently than their nearer and older counterparts.

    A paper describing these results is appearing in The Astrophysical Journal Letters. The authors are Julie Hlavacek-Larrondo (University of Montreal in Canada), Carter Rhea (University of Montreal), Tracy Webb (McGill University, Canada), Michael McDonald (Massachusetts Institute of Technology), A. Muzzin (York University, Canada), G. Wilson (University of California, Riverside), K. Finner (Yonsei University, Korea), F. Valin (McGill), N. Bonventura (University of Copahagen, Denmark), M. Cooper (University of California, Irvine), Andy Fabian (Institute of Astronomy, Cambridge, United Kingdom), M.-L Gendron-Marsolais (European Southern Observatory), J.M. Lee (Yonsei), C. Lidman (Australian National University), Mar Mezcua (Institute of Space Sciences, Spain), A. Noble (Arizona State University), H.R. Russell (Institute of Astronomy, Cambridge), J. Surace (IPAC, Caltech), A. Trudeau (University of Victoria, Canada), and H.K.C. Yee (University of Toronto).


    Quick Look: Black Hole Fails to Do Its Job

    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 10:57 am on July 29, 2020 Permalink | Reply
    Tags: "Extended X-ray emission detected from the radio galaxy 4C 63.20", , , At a redshift of approximately 4.261- 4C 63.20 is one of only few known HzRGs., , , High-redshift radio galaxies (HzRGs) which are among the most massive galaxies at their redshift are known to contain large amounts of dust and gas., NASA Chandra, , Radio galaxies emit huge amounts of radio waves from their central cores.   

    From NASA Chandra via phys.org: “Extended X-ray emission detected from the radio galaxy 4C 63.20” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    via


    phys.org

    1
    Credit: CC0 Public Domain

    Using NASA’s Chandra X-ray Observatory, an international team of astronomers has conducted deep imaging observations of a high-redshift radio galaxy known as 4C 63.20. The observational campaign has revealed an extended X-ray emission from this source. The finding is reported in a paper published July 20 on the arXiv pre-print paper [ MNRAS, “Extended X-ray emission from the z=4.26 radio galaxy 4C 63.20” ( https://arxiv.org/abs/2007.10368 ).

    Radio galaxies emit huge amounts of radio waves from their central cores. Black holes at the centers of these galaxies accrete gas and dust, generating high-energy jets visible in radio wavelengths, which accelerate electrically charged particles to high velocities.

    High-redshift radio galaxies (HzRGs), which are among the most massive galaxies at their redshift, are known to contain large amounts of dust and gas. HzRGs are often located at the center of clusters and proto-clusters of galaxies. They could provide insights into the assembly and evolution of large-scale structures in the universe.

    At a redshift of approximately 4.261, 4C 63.20 is one of only few known HzRGs. It is also the only HzRG to have an associated, statistically significant X-ray counterpart at a redshift of above 4.0. Recently, a group of astronomers led by Kate Napier of the University of Michigan investigated this X-ray source using the Advanced CCD Imaging Spectrometer (ACIS), an X-ray imager aboard Chandra.

    “In this paper, we report on deep observations of 4C 63.20 with the Chandra X-ray Observatory, aimed at testing the cosmic microwave background-quenching model by resolving its X-ray emission on sub-arcsec scales,” the researchers wrote in the study.

    Chandra observations show that the X-ray counterpart to 4C 63.20 is made of a compact core plus extended southeast-to-northwest emission. This extended X-ray emission accounts for about 30 percent of the flux and turned out be aligned with the radio hotspots of 4C 63.20 seen at 5.0 GHz. The astronomers noted that although the observed separation and centroid positions of the two X-ray sources point out to a diffuse, lobe-like nature, the scenario that they are two compact hotspots cannot be ruled out at the moment.

    Trying to reproduce the spectral energy distribution (SED) of the 4C 63.20 system, the researchers found that it could be described by a jet model attributing the majority of the radio flux to synchrotron emission from the hotspots. When it comes to the X-ray emission, it can be produced via inverse Compton (IC) scattering off of disc, torus and cosmic microwave background (CMB) photons.

    “This scenario is broadly consistent with the expectation from highly magnetized lobes in a hotter CMB, and supports the view that IC/CMB may quench less extreme radio lobes at high redshifts,” the authors of the paper explained.

    Summing up the results, the astronomers concluded that the case of 4C 63.20 shows that HzRGs are clearly not radio-quenched; however, X-ray luminosities of these sources are consistent with the expectation from highly magnetized lobes in a hotter CMB.

    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 1:29 pm on July 15, 2020 Permalink | Reply
    Tags: "Cases of Black Hole Mistaken Identity", , , , , NASA Chandra   

    From NASA Chandra: “Cases of Black Hole Mistaken Identity” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    1
    X-ray: NASA/CXC/Penn State/B.Luo et al; Illustration: NASA/CXC/M. Weiss

    2
    Credit: NASA/CXC/Penn State/B.Luo et al.

    Astronomers have discovered over two dozen growing supermassive black holes that had been misidentified before.

    This result used data from several telescopes including NASA’s Chandra X-ray Observatory, and the Hubble and Spitzer Space Telescopes.

    NASA/ESA Hubble Telescope

    NASA/Spitzer Infrared Telescope. No longer in service

    The 28 supermassive black holes were found in the Chandra Deep Field-South, the deepest X-ray image ever obtained.

    3
    Image credit: X-ray: NASA/CXC/U.Hawaii/E.Treister et al; Infrared: NASA/STScI/UC Santa Cruz/G.Illingworth et al; Optical: NASA/STScI/S.Beckwith et al.
    This composite image from NASA’s Chandra X-ray Observatory and Hubble Space Telescope (HST) combines the deepest X-ray, optical and infrared views of the sky. Using these images, astronomers have obtained the first direct evidence that black holes are common in the early Universe and shown that very young black holes grew more aggressively than previously thought.
    Astronomers obtained what is known as the Chandra Deep Field South (CDFS) by pointing the telescope at the same patch of sky for over six weeks of time. The composite image shows a small section of the CDFS, where the Chandra sources are blue, the optical HST data are shown in green and blue, and the infrared data from Hubble are in red and green.
    The new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the Universe was between about 800 million and 950 million years old. These distant galaxies were detected using the HST data and the positions of a subset of them are marked with the yellow circles (roll your mouse over the image above).
    The rest of the 200 galaxies were found in other deep HST observations located either elsewhere in the CDFS or the Chandra Deep Field North, a second ultra- deep Chandra field in a different part of the sky.
    None of the galaxies was individually detected with Chandra, so the team used a technique that relied on Chandra’s ability to very accurately determine the direction from which the X-rays came to add up all the X-ray counts near the positions of these distant galaxies. The two “stacked” images resulting from this analysis are on the right side of the graphic, where the bottom image shows the low-energy X- rays and the top image has the high-energy X-rays. Statistically significant signals are found in both images.
    These results imply that between 30% and 100% of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the relatively small field of view that was observed to the full sky, there are at least 30 million supermassive black holes in the early Universe. This is a factor of 10,000 larger than the estimated number of quasars in the early Universe.
    The stronger signal in high-energy X-rays implies that the black holes are nearly all enshrouded in thick clouds of gas and dust. Although copious amounts of optical light are generated by material falling onto the black holes, this light is blocked within the core of the black hole’s host galaxy and is undetectable by optical telescopes. However, the high energies of X-ray light can penetrate these veils, allowing the black holes inside to be studied.

    The discovery has important implications for understanding how supermassive black holes grow and evolve over billions of years.

    A team of researchers has identified a group of black holes that had previously been mistaken for a different kind of black hole, as described in our latest press release. This discovery has important implications for understanding how supermassive black holes grow and evolve over billions of years.

    The misjudged black holes were found in the Chandra Deep Field-South (CDF-S), the deepest X-ray image ever taken. The main panel of the graphic shows the CDF-S, which contains over 7 million seconds of observing time from Chandra collected over many years. In this image, red, green, and blue represent the low, medium, and high-energy X-rays that Chandra can detect. Most of the points in this image are a black hole.

    This latest work combines X-rays from Chandra in the CDF-S with large amounts of data at different wavelengths from other observatories, including NASA’s Hubble Space Telescope and NASA’s Spitzer Space Telescope. The team looked at black holes located 5 billion light years or more away from Earth in this patch of sky. At these distances, scientists had already found 67 heavily obscured, growing black holes with both X-ray and infrared data in the CDF-S. In this latest study, the authors identified another 28, highlighted by circles in a labeled version of the image. Optical and infrared images for four of these 28 are shown in a separate graphic.

    These 28 supermassive black holes were previously categorized differently — either as slowly growing black holes with low density or nonexistent cocoons, or as distant galaxies. Supermassive black holes grow by pulling in surrounding material, which is heated and produces radiation at a wide range of wavelengths including X-rays. Many astronomers think this growth includes a phase, which happened billions of years ago, when a dense cocoon of dust and gas covers most black holes. These cocoons of material, which are the fuel source that enables the black hole to grow and generate radiation, are depicted in the artist’s illustration in the inset. The cocoon (red) surrounds a disk of material falling onto the black hole, plus a wind of material (blue) blowing away from the disk. A portion of the cocoon is cut out to show the heavily obscured black hole.

    These results are important for theoretical models estimating the number of black holes in the universe and their growth rates, including those with different amounts of obscuration. Scientists design these models to explain a uniform glow in X-rays across the sky called the “X-ray background,” first discovered in the 1960s. Individual growing black holes observed in images like the CDF-S account for most of the X-ray background.

    A paper reporting the results of this study is being published in The Astrophysical Journal. The other authors of the paper are Erini Lambrides (Johns Hopkins University in Baltimore, Maryland), Marco Chiaberge (Space Telescope Science Institute in Baltimore, Maryland), Roberto Gilli (National Institute of Astrophysics in Bologna, Italy), Timothy Heckman (Johns Hopkins), Fabio Vito (Pontificia Universidad Católica de Chile in Santiago), and Colin Norman (Johns Hopkins).


    A Quick Look at Cases of Black Hole Mistakenly identified.

    The above referenced press release is by
    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 3:16 pm on June 18, 2020 Permalink | Reply
    Tags: "X-rays From a Newborn Star Hint at Our Sun's Earliest Days", An object called HOPS 383 in the star-forming region of the Orion Molecular Cloud Complex, , , , , NASA Chandra   

    From NASA Chandra: “X-rays From a Newborn Star Hint at Our Sun’s Earliest Days” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    June 18, 2020
    Molly Porter
    NASA Marshall Space Flight Center, Huntsville, Ala.
    256-424-5158
    molly.a.porter@nasa.gov

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

    1
    X-ray: NASA/CXC/Aix-Marseille University/N. Grosso et al.; Illustration: NASA/CXC/M. Weiss

    Astronomers have reported the first detection of X-rays from the earliest phase of evolution of a star like our Sun.

    This discovery from NASA’s Chandra X-ray Observatory may help answer questions about the Sun and Solar System as they are today.

    The X-ray flare came from the young “protostar” HOPS 383, about 1,400 light years from Earth, during Chandra observations taken in December 2017.

    This result may reset the timeline for when astronomers think Sun-like stars start blasting X-rays into space.

    Astronomers have reported the first detection of X-rays from the earliest phase of evolution of a star like our Sun. This discovery, made using NASA’s Chandra X-ray Observatory, may help answer some questions about the Sun and the Solar System as they are today.

    The X-rays came from a flare emitted by an object called HOPS 383, located about 1,400 light years from Earth in the star-forming region of the Orion Molecular Cloud Complex. Astronomers refer to HOPS 383 as a young “protostar” because it is in the earliest phase of stellar evolution that occurs right after a large cloud of gas and dust has started to collapse. Once it has matured HOPS 383 will have a mass about half that of the Sun.

    This result is significant because it resets the timeline for when astronomers think Sun-like stars start blasting X-rays into space. While scientists know that young stars are much more active in X-rays than older ones, they have debated just when X-ray emission begins.

    “We don’t have a time machine that lets us directly observe our Sun as it was beginning its life, but the next best thing is to look at analogs of it like HOPS 383,” said lead author Nicolas Grosso of Astrophysics Laboratory of Marseille at Aix-Marseille University in France. “From these, we can reconstruct important parts of our own Solar System’s past.”

    Chandra observations in December 2017 revealed the X-ray flare in HOPS 383, which lasted for about 3 hours and 20 minutes. No X-rays were detected from the protostar outside this flaring period, implying that during these times HOPS 383 was at least ten times fainter, on average, than the flare at its maximum. It is also 2,000 times more powerful than the brightest X-ray flare observed from the Sun, a middle-aged star of relatively low mass.

    During the earliest stages of evolution of protostars — as represented by objects like HOPS 383 — about half of the protostar’s mass likely still resides in a cocoon of dust and gas that is falling onto a disk surrounding the central star. Light from the infant star in HOPS 383 must pierce through this cocoon. Fortunately, X-rays are powerful enough to do just that.

    As material from the cocoon falls inward toward the disk, there is also an exodus of gas and dust. This “outflow” removes angular momentum from the system, allowing material to fall from the disk onto the growing young protostar. Astronomers have seen a such outflow from HOPS 383 and think powerful X-ray flare like the one observed by Chandra could strip electrons from atoms at the base of it. This may be important for driving the outflow by magnetic forces.

    “If this connection between X-ray flares and outflows is correct, similar flares may have played an important role in forming our life-giving host star, the Sun”, said co-author Kenji Hamaguchi of Center for Research and Exploration in Space Science & Technology and NASA’s Goddard Space Flight Center in Greenbelt, MD.

    Furthermore, when the star erupted in X-rays, it would have also likely driven energetic flows of particles that collided with dust grains located at the inner edge of the disk of material swirling around the protostar. Assuming something similar happened in our Sun, the nuclear reactions caused by this collision could explain unusual abundances of elements in certain types of meteorites found on Earth.

    “What the Sun did over 4.5 billion years ago affected the raw material that ended up making the planets and everything else in our Solar System,” said co-author David Principe of the Massachusetts Institute of Technology in Cambridge. “Any X-rays from a young Sun may have played a big role in shaping those ingredients.”

    No other flares from HOPS 383 were detected over the course of three Chandra observations with a total exposure of just under a day. Astronomers will need longer X-ray observations to determine how frequent such flares are during this very early phase of development for stars like our Sun.

    “How common are X-ray flares from the youngest protostars and how much of an influence do they have on the development of solar systems?” asked co-author Joel Kastner of the Rochester Institute of Technology in New York. “Only more observations can answer these important questions.”

    A paper describing these results appeared in the journal of Astronomy & Astrophysics.

    3
    A version of the illustration with a region of the cocoon cut out shows the bright X-ray flare from HOPS 383 and a disk of material falling towards the protostar. Credit: NASA/CXC/M.Weiss


    A quick look at X-rays from a newborn star

    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 11:46 am on May 30, 2020 Permalink | Reply
    Tags: "MAXI J1820+070: Black Hole Outburst Caught on Video", , , , , NASA Chandra   

    From NASA Chandra: “MAXI J1820+070: Black Hole Outburst Caught on Video” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    A pair of jets blasting away from a black hole at 80% the speed of light has been observed by astronomers.

    The stellar-mass black hole (about 8 times the mass of the Sun) is pulling material away from a closely orbiting companion star.

    Some of this material does not fall into the black hole and is instead redirected outward as jets.

    Four observations from NASA’s Chandra X-ray Observatory taken in 2018 and 2019 allowed astronomers to detect the jets as they slam into surrounding material.

    Astronomers have caught a black hole hurling hot material into space at close to the speed of light. This flare-up was captured in a new movie from NASA’s Chandra X-ray Observatory.

    1

    The black hole and its companion star make up a system called MAXI J1820+070, located in our Galaxy about 10,000 light years from Earth. The black hole in MAXI J1820+070 has a mass about eight times that of the Sun, identifying it as a so-called stellar-mass black hole, formed by the destruction of a massive star. (This is in contrast to supermassive black holes that contain millions or billions of times the Sun’s mass.)

    The companion star orbiting the black hole has about half the mass of the Sun. The black hole’s strong gravity pulls material away from the companion star into an X-ray emitting disk surrounding the black hole.

    While some of the hot gas in the disk will cross the “event horizon” (the point of no return) and fall into the black hole, some of it is instead blasted away from the black hole in a pair of short beams of material, or jets. These jets are pointed in opposite directions, launched from outside the event horizon along magnetic field lines. The new footage of this black hole’s behavior is based on four observations obtained with Chandra in November 2018 and February, May, and June of 2019, and reported in a paper led by Mathilde Espinasse of the Université de Paris.

    The main panel of the graphic is a large optical and infrared image of the Milky Way galaxy from the PanSTARRS optical telescope in Hawaii, with the location of MAXI J1820+070 above the plane of the galaxy marked by a cross. The inset shows a movie that cycles through the four Chandra observations, where “day 0” corresponds to the first observation on November 13th, 2018, about four months after the jet’s launch. MAXI J1820+070 is the bright X-ray source in the middle of the image and sources of X-rays can be seen moving away from the black hole in jets to the north and south. MAXI J1820+070 is a point source of X-rays, although it appears to be larger than a point source because it is much brighter than the jet sources. The southern jet is too faint to be detected in the May and June 2019 observations.

    Just how fast are the jets of material moving away from the black hole? From Earth’s perspective, it looks as if the northern jet is moving at 60% the speed of light, while the southern one is traveling at an impossible-sounding 160% of light speed!

    This is an example of superluminal motion, a phenomenon that occurs when something travels towards us near the speed of light, along a direction close to our line of sight. This means the object travels almost as quickly towards us as the light it generates, giving the illusion that the jet’s motion is more rapid than the speed of light. In the case of MAXI J1820+070, the southern jet is pointing towards us and the northern jet is pointing away from us, so the southern jet appears to be moving faster than the northern one. The actual velocity of the particles in both jets is greater than 80% of the speed of light.

    2
    Credit: NASA/CXC/M.Weiss


    A Quick Look at a Black Hole Outburst

    Only two other examples of such high-speed expulsions have been seen in X-rays from stellar-mass black holes.

    MAXI J1820+070 has also been observed at radio wavelengths by a team led by Joe Bright from the University of Oxford, who previously reported the detection of superluminal motion of compact sources based on radio data alone that extended from the launch of the jets on July 7, 2018 to the end of 2018.

    Because the Chandra observations approximately doubled the length of time the jets were followed, a combined analysis of the radio data and the new Chandra data by Espinasse and her team gave more information about the jets. This included evidence that the jets are decelerating as they travel away from the black hole.

    Most of the energy in the jets is not converted into radiation, but is instead released when particles in the jets interact with surrounding material. These interactions might be the cause of the jets’ deceleration. When the jets collide with surrounding material in interstellar space, shock waves — akin to the sonic booms caused by supersonic aircraft — occur. This process generates particle energies that are higher than that of the Large Hadron Collider.

    The researchers estimate that about 400 million billion pounds of material was blown away from the black hole in these two jets launched in July 2018. This amount of mass is comparable to what could be accumulated on the disk around the black hole in the space of a few hours, and is equivalent to about a thousand Halley’s Comets or about 500 million times the mass of the Empire State Building.

    Studies of MAXI J1820+070 and similar systems promise to teach us more about the jets produced by stellar-mass black holes and how they release their energy once their jets interact with their surroundings.

    Radio observations conducted with the Karl G. Jansky Very Large Array and the MeerKAT array were also used to study MAXI J1820+070’s jets.

    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)

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

    A paper describing these results is published in the latest edition of The Astrophysical Journal Letters. The authors of the paper are Mathilde Espinasse and Stéphane Corbel (Université de Paris, Paris, France), Philip Kaaret (University of Iowa, Iowa City, Iowa), Evangelia Tremou (Université de Paris , Paris, France), Giulia Migliori (Institute of Radio Astronomy of Bologna, Bologna, Italy), Richard M. Plotkin (University of Nevada, Reno, Nevada), Joe Bright (University of Oxford, Oxford, UK), John Tomsick (University of California, Berkeley, California), Anastasios Tzioumis (Australia Telescope National Facility, CSIRO, Epping, Australia), Rob Fender (University of Oxford, Oxford, UK), Jerome A. Orosz (San Diego State University, San Diego, California), Elena Gallo (University of Michigan, Ann Arbor, Michigan), Jeroen Homan (Eureka Scientific, Oakland, California), Peter G. Jonker (Radboud University, Nijmegen, the Netherlands), James C. A. Miller-Jones (Curtin University, Perth, Australia), David M. Russell (New York University Abu Dhabi, Abu Dhabi, UAE), and Sara Motta (University of Oxford, Oxford, UK).

    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 11:56 am on May 11, 2020 Permalink | Reply
    Tags: "Abell 2384: Bending the Bridge Between Two Galaxy Clusters", , , , , NASA Chandra   

    From NASA Chandra: “Abell 2384: Bending the Bridge Between Two Galaxy Clusters” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    May 11, 2020

    1
    Composite

    2
    X-ray

    3
    Optical

    4
    Radio

    A bridge of gas extending over three million light years from two galaxy clusters has been spotted.

    The two clusters collided several hundred million years ago and then passed through each other to arrive in this configuration.

    The collision released a large amount of hot gas that now spans the distance between the two clusters.

    This superheated bridge of gas glows brightly in X-rays, which Chandra and XMM-Newton have detected.

    Several hundred million years ago, two galaxy clusters collided and then passed through each other. This mighty event released a flood of hot gas from each galaxy cluster that formed an unusual bridge between the two objects. This bridge is now being pummeled by particles driven away from a supermassive black hole.

    Galaxy clusters are the largest objects in the universe held together by gravity. They contain hundreds or thousands of galaxies, vast amounts of multi-million-degree gas that glow in X-rays, and enormous reservoirs of unseen dark matter.

    The system known as Abell 2384 shows the giant structures that can result when two galaxy clusters collide. A superheated gas bridge in Abell 2384 is shown in this composite image of X-rays from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton (blue), as well as the Giant Metrewave Radio Telescope in India (red).

    ESA/XMM Newton

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

    This new multi-wavelength view reveals the effects of a jet shooting away from a supermassive black hole in the center of a galaxy in one of the clusters. The jet is so powerful that it is bending the shape of the gas bridge, which extends for over 3 million light years and has the mass of about 6 trillion Suns.

    A labeled version of the image traces the shape of the bridge, marks the position of the supermassive black hole, and shows where the jet is pushing the hot gas in the bridge sideways at the collision site. The lobe of radio emission marking the end of each jet is also shown. At the collision site, astronomers found evidence for a shock front, similar to a sonic boom from a supersonic aircraft, which can keep the gas hot and prevent it from cooling to form new stars.

    The radio emission extends about 1.2 million light years from the black hole to the north and about 1.7 million light years to the south. The northern radio emission is also fainter than the southern emission. These differences might be explained by the radio emission to the north being slowed down by the jet’s impact with the hot gas in the bridge.

    Chandra has often observed cavities in hot gas created by jets in the centers of galaxy clusters, such as the Perseus cluster, MS 0735 and the Ophiuchus Cluster. However, Abell 2384 offers a rare case of such an interaction occurring in the outer region of a cluster. It is also unusual that the supermassive black hole driving the jet is not in the largest galaxy located in the center of the cluster.

    Astronomers consider objects like Abell 2384 to be important for understanding the growth of galaxy clusters. Based on computer simulations, it has been shown that after a collision between two galaxy clusters, they oscillate like a pendulum and pass through each other several times before merging to form a larger cluster. Based on these simulations, astronomers think that the two clusters in Abell 2384 will eventually merge.

    Abell 2384 is located 1.2 billion light years from Earth. Based on previous work, scientists estimate the total mass of Abell 2384 is 260 trillion times the mass of the Sun. This includes the dark matter, hot gas and the individual galaxies.

    A paper describing this work was published in the January 2020 issue of the Monthly Notices of the Royal Astronomical Society, and is available online. The authors are Viral Parekh (South African Radio Astronomy Observatory and Rhodes University, South Africa); Tatiana Lagana (Universidade Cruzeiro do Sul/Universidade Cidade de São Paulo, Brazil); Kshitij Thorat (Rhodes University); Kurt van der Heyden (University of Cape Town, South Africa); Asif Iqbal Ahanger (Raman Research Institute, India); and Florence Durret (Institut d’Astrophysique de Paris and Sorbonne Université, France).

    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 9:35 am on April 25, 2020 Permalink | Reply
    Tags: "Star Survives Close Call with a Black Hole", , , , , GSN 069 is now caught in an elliptical orbit around the black hole making one trip around about once every nine hours.", It will try hard to get away but there is no escape., NASA Chandra, The black hole located in a galaxy called GSN 069 has a mass about 400000 times that of the Sun- putting it on the small end of the scale for supermassive black holes.,   

    From NASA Chandra: “Star Survives Close Call with a Black Hole” 

    NASA Chandra Banner

    NASA/Chandra Telescope


    From NASA Chandra

    April 23, 2020

    Media contacts:
    Molly Porter
    NASA Marshall Space Flight Center, Huntsville, Ala.
    256-424-5158
    molly.a.porter@nasa.gov

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

    1
    X-ray: NASA/CXO/CSIC-INTA/G.Miniutti et al.; Illustration: NASA/CXC/M. Weiss;

    Astronomers may have discovered a new kind of survival story: a star that had a brush with a giant black hole and lived to tell the tale through exclamations of X-rays.

    Data from NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton uncovered the account that began with a red giant star wandering too close to a supermassive black hole in a galaxy about 250 million light years from Earth.

    ESA/XMM Newton

    The black hole, located in a galaxy called GSN 069, has a mass about 400,000 times that of the Sun, putting it on the small end of the scale for supermassive black holes.

    Once the red giant was captured by the black hole’s gravity, the outer layers of the star containing hydrogen were stripped off and careened toward the black hole, leaving the core of the star — known as a white dwarf — behind.

    “In my interpretation of the X-ray data the white dwarf survived, but it did not escape,” said Andrew King of the University of Leicester in the UK, who performed this study. “It is now caught in an elliptical orbit around the black hole, making one trip around about once every nine hours.”

    As the white dwarf makes its nearly thrice-daily orbit, the black hole pulls material off at its closest approach (no more than 15 times the radius of the event horizon — the point of no return — away from the black hole). The stellar detritus enters into a disk surrounding the black hole and releases a burst of X-rays that Chandra and XMM-Newton can detect. In addition, King predicts gravitational waves will be emitted by the black hole and white dwarf pair, especially at their nearest point.

    What would be the future of the star and its orbit? The combined effect of gravitational waves and a change in the star’s size as it loses mass should cause the orbit to become more circular and grow in size. The rate of mass loss steadily slows down, as does the increase in the white dwarf’s distance from the black hole.

    “It will try hard to get away, but there is no escape. The black hole will eat it more and more slowly, but never stop,” said King. “In principle, this loss of mass would continue until and even after the white dwarf dwindled down to the mass of Jupiter, in about a trillion years. This would be a remarkably slow and convoluted way for the universe to make a planet!”

    Astronomers have found many stars that have been completely torn apart by encounters with black holes (so-called tidal disruption events), but there are very few reported cases of near misses, where the star likely survived.

    Grazing encounters like this should be more common than direct collisions given the statistics of cosmic traffic patterns, but they could easily be missed for a couple of reasons. First, it can take a more massive, surviving star too long to complete an orbit around a black hole for astronomers to see repeated bursts. Another issue is that supermassive black holes that are much more massive than the one in GSN 069 may directly swallow a star rather than the star falling into orbits where they periodically lose mass. In these cases, astronomers wouldn’t observe anything.

    “In astronomical terms, this event is only visible to our current telescopes for a short time — about 2,000 years,” said King. “So unless we were extraordinarily lucky to have caught this one, there may be many more that we are missing. Such encounters could be one of the main ways for black holes the size of the one in GSN 069 to grow.”

    King predicts that the white dwarf has a mass of only two tenths the mass of the Sun. If the white dwarf was the core of the red giant that was completely stripped of its hydrogen, then it should be rich in helium. The helium would have been created by the fusion of hydrogen atoms during the evolution of the red giant.

    “It’s remarkable to think that the orbit, mass and composition of a tiny star 250 million light years away could be inferred,” said King.

    King made a prediction based on his scenario. Because the white dwarf is so close to the black hole, effects from the Theory of General Relativity mean that the direction of the orbit’s axis should wobble, or “precess.” This wobble should repeat every two days and may be detectable with sufficiently long observations.

    A paper describing these results appears in the March 2020 issue of the Monthly Notices of the Royal Astronomical Society, and is available online.

    Other materials about the findings are available at:
    http://chandra.si.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 2:29 pm on March 31, 2020 Permalink | Reply
    Tags: "Hubble Finds Best Evidence for Elusive Mid-Sized Black Hole", (IMBH)-intermediate-mass black hole, , , , , , NASA Chandra, , The X-ray source named 3XMM J215022.4−055108   

    From NASA/ESA Hubble Telescope: “Hubble Finds Best Evidence for Elusive Mid-Sized Black Hole” 

    NASA/ESA Hubble Telescope

    From NASA/ESA Hubble Telescope

    March 31, 2020

    Leah Ramsay
    Space Telescope Science Institute, Baltimore, Maryland
    667-218-6439
    lramsay@stsci.edu

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

    Dacheng Lin
    University of New Hampshire, Durham, New Hampshire
    dacheng.lin@unh.edu

    High-resolution imaging reveals black hole’s hideout in extra-galactic star cluster.

    1
    About This Image. Illustration of Mid-Sized Black Hole Eating a Star
    This artist’s concept depicts a cosmic homicide in action. A wayward star is being shredded by the intense gravitational pull of a black hole that contains tens of thousands of solar masses. The stellar remains are forming an accretion disk around the black hole. Flares of X-ray light from the super-heated gas disk alerted astronomers to the black hole’s location; otherwise it lurked unknown in the dark. The elusive object is classified as an intermediate-mass black hole (IMBH), as it is much less massive than the monster black holes that dwell in the centers of galaxies. Therefore, IMBHs are mostly quiescent because they do not pull in as much material, and are hard to find. Hubble observations provide evidence that the IMBH dwells inside a dense star cluster. The cluster itself may be the stripped-down core of a dwarf galaxy. Credits: NASA/ESA and D. Player (STScI)

    Astronomers have found the best evidence for the perpetrator of a cosmic homicide: a black hole of an elusive class known as “intermediate-mass,” which betrayed its existence by tearing apart a wayward star that passed too close.

    Weighing in at about 50,000 times the mass of our Sun, the black hole is smaller than the supermassive black holes (at millions or billions of solar masses) that lie at the cores of large galaxies, but larger than stellar-mass black holes formed by the collapse of a massive star.

    These so-called intermediate-mass black holes (IMBHs) are a long-sought “missing link” in black hole evolution. Though there have been a few other IMBH candidates, researchers consider these new observations the strongest evidence yet for mid-sized black holes in the universe.

    It took the combined power of two X-ray observatories and the keen vision of NASA’s Hubble Space Telescope to nail down the cosmic beast.

    “Intermediate-mass black holes are very elusive objects, and so it is critical to carefully consider and rule out alternative explanations for each candidate. That is what Hubble has allowed us to do for our candidate,” said Dacheng Lin of the University of New Hampshire, principal investigator of the study. The results are published on March 31, 2020 in The Astrophysical Journal Letters.

    The story of the discovery reads like a Sherlock Holmes story, involving the meticulous step-by-step case-building necessary to catch the culprit.

    Lin and his team used Hubble to follow up on leads from NASA’s Chandra X-ray Observatory and the European Space Agency’s X-ray Multi-Mirror Mission (XMM-Newton).

    NASA/Chandra X-ray Telescope

    ESA/XMM Newton

    In 2006 these high-energy satellites detected a powerful flare of X-rays, but were not sure if they originated from inside or outside of our galaxy. Researchers attributed it to a star being torn apart after coming too close to a gravitationally powerful compact object, like a black hole.

    Surprisingly, the X-ray source, named 3XMM J215022.4−055108, was not located in a galaxy’s center, where massive black holes normally would reside. This raised hopes that an IMBH was the culprit, but first another possible source of the X-ray flare had to be ruled out: a neutron star in our own Milky Way galaxy, cooling off after being heated to a very high temperature. Neutron stars are the crushed remnants of an exploded star.

    Hubble was pointed at the X-ray source to resolve its precise location. Deep, high-resolution imaging provides strong evidence that the X-rays emanated not from an isolated source in our galaxy, but instead in a distant, dense star cluster on the outskirts of another galaxy — just the type of place astronomers expected to find an IMBH. Previous Hubble research has shown that the mass of a black hole in the center of a galaxy is proportional to that host galaxy’s central bulge. In other words, the more massive the galaxy, the more massive its black hole. Therefore, the star cluster that is home to 3XMM J215022.4−055108 may be the stripped down core of a lower-mass dwarf galaxy that has been gravitationally and tidally disrupted by its close interactions with its current larger galaxy host.

    IMBHs have been particularly difficult to find because they are smaller and less active than supermassive black holes; they do not have readily available sources of fuel, nor as strong a gravitational pull to draw stars and other cosmic material which would produce telltale X-ray glows. Astronomers essentially have to catch an IMBH red-handed in the act of gobbling up a star. Lin and his colleagues combed through the XMM-Newton data archive, searching hundreds of thousands of observations to find one IMBH candidate.

    The X-ray glow from the shredded star allowed astronomers to estimate the black hole’s mass of 50,000 solar masses. The mass of the IMBH was estimated based on both X-ray luminosity and the spectral shape. “This is much more reliable than using X-ray luminosity alone as typically done before for previous IMBH candidates,” said Lin. “The reason why we can use the spectral fits to estimate the IMBH mass for our object is that its spectral evolution showed that it has been in the thermal spectral state, a state commonly seen and well understood in accreting stellar-mass black holes.”

    This object isn’t the first to be considered a likely candidate for an intermediate-mass black hole. In 2009 Hubble teamed up with NASA’s Swift observatory and the XMM-Newton X-ray space telescope to identify what is interpreted as an IMBH, called HLX-1, located towards the edge of the galaxy ESO 243-49.

    NASA Neil Gehrels Swift Observatory

    It too is in the center of a young, massive cluster of blue stars, that may be a stripped down dwarf galaxy core. The X-rays come from a hot accretion disk around the black hole. “The main difference is that our object is tearing a star apart, providing strong evidence that it is a massive black hole, instead of a stellar-mass black hole as people often worry about for previous candidates including HLX-1,” Lin said.

    Finding this IMBH opens the door to the possibility of many more lurking undetected in the dark, waiting to be given away by a star passing too close. Lin plans to continue his meticulous detective work, using the methods his team has proved successful. Many questions remain to be answered. Does a supermassive black hole grow from an IMBH? How do IMBHs themselves form? Are dense star clusters their favored home?

    See the full article here .


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

    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.

    ESA50 Logo large

     
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
%d bloggers like this: