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  • richardmitnick 2:20 pm on January 9, 2017 Permalink | Reply
    Tags: , , , , , Supermassive Black Holes   

    From JPL-Caltech: “Black Holes Hide in Our Cosmic Backyard” 

    NASA JPL Banner

    JPL-Caltech

    January 7, 2017
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    Elizabeth.landau@jpl.nasa.gov

    1
    IC 3639, a galaxy with an active galactic nucleus, is seen in this image combining data from NASA’s Hubble Space Telescope and the European Southern Observatory.

    NASA/ESA Hubble Telescope
    NASA/ESA Hubble Telescope

    ESO/Cerro LaSilla,  600 km north of Santiago de Chile at an altitude of 2400 metres
    ESO/Cerro LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres

    ESO Paranal Facilities
    ESO Paranal Facilities

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

    NASA/NuSTAR
    NASA/NuSTAR

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    JAXA Suzaku ISAS telescope
    Suzaku ISAS telescope

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

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

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

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

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

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

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

    Boorman led the study of an active galaxy called IC 3639, which is 170 million light years away. Researchers analyzed NuSTAR data from this object and compared them with previous observations from NASA’s Chandra X-Ray Observatory and the Japan-led Suzaku satellite. The findings from NuSTAR, which is more sensitive to higher energy X-rays than these observatories, confirm the nature of IC 3639 as an active galactic nucleus. NuSTAR also provided the first precise measurement of how much material is obscuring the central engine of IC 3639, allowing researchers to determine how luminous this hidden monster really is.

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

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

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

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

    See the full article here .

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 1:48 pm on December 31, 2016 Permalink | Reply
    Tags: , , , Black hole seeds, , , NASA Telescopes Find Clues For How Giant Black Holes Formed So Quickly, Supermassive Black Holes   

    From NASA: “NASA Telescopes Find Clues For How Giant Black Holes Formed So Quickly” 

    NASA image
    NASA

    May 24, 2016 [Picked up for year end.]
    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

    Sean Potter
    Headquarters, Washington
    202-358-1536
    sean.potter@nasa.gov

    1
    This illustration represents the best evidence to date that the direct collapse of a gas cloud produced supermassive black holes in the early Universe. Researchers combined data from NASA’s Chandra, Hubble, and Spitzer telescopes to make this discovery. Credits: NASA/CXC/STScI

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    NASA/ESA Hubble Telescope
    NASA/ESA Hubble Telescope

    NASA/Spitzer Telescope
    NASA/Spitzer Telescope

    Using data from NASA’s Great Observatories, astronomers have found the best evidence yet for cosmic seeds in the early universe that should grow into supermassive black holes.

    Researchers combined data from NASA’s Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope to identify these possible black hole seeds. They discuss their findings in a paper that will appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.

    “Our discovery, if confirmed, explains how these monster black holes were born,” said Fabio Pacucci of Scuola Normale Superiore (SNS) in Pisa, Italy, who led the study. “We found evidence that supermassive black hole seeds can form directly from the collapse of a giant gas cloud, skipping any intermediate steps.”

    Scientists believe a supermassive black hole lies in the center of nearly all large galaxies, including our own Milky Way. They have found that some of these supermassive black holes, which contain millions or even billions of times the mass of the sun, formed less than a billion years after the start of the universe in the Big Bang.

    One theory suggests black hole seeds were built up by pulling in gas from their surroundings and by mergers of smaller black holes, a process that should take much longer than found for these quickly forming black holes.

    These new findings suggest instead that some of the first black holes formed directly when a cloud of gas collapsed, bypassing any other intermediate phases, such as the formation and subsequent destruction of a massive star.

    “There is a lot of controversy over which path these black holes take,” said co-author Andrea Ferrara, also of SNS. “Our work suggests we are narrowing in on an answer, where the black holes start big and grow at the normal rate, rather than starting small and growing at a very fast rate.”

    The researchers used computer models of black hole seeds combined with a new method to select candidates for these objects from long-exposure images from Chandra, Hubble, and Spitzer.

    The team found two strong candidates for black hole seeds. Both of these matched the theoretical profile in the infrared data, including being very red objects, and also emit X-rays detected with Chandra. Estimates of their distance suggest they may have been formed when the universe was less than a billion years old

    “Black hole seeds are extremely hard to find and confirming their detection is very difficult,” said Andrea Grazian, a co-author from the National Institute for Astrophysics in Italy. “However, we think our research has uncovered the two best candidates to date.”

    The team plans to obtain further observations in X-rays and the infrared to check whether these objects have more of the properties expected for black hole seeds. Upcoming observatories, such as NASA’s James Webb Space Telescope and the European Extremely Large Telescope will aid in future studies by detecting the light from more distant and smaller black holes. Scientists currently are building the theoretical framework needed to interpret the upcoming data, with the aim of finding the first black holes in the universe.

    “As scientists, we cannot say at this point that our model is ‘the one’,” said Pacucci. “What we really believe is that our model is able to reproduce the observations without requiring unreasonable assumptions.”

    NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program while the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.

    NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission, whose science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado.

    For more on NASA’s Chandra X-ray Observatory, visit:

    http://www.nasa.gov/chandra

    For more on NASA’s Hubble Space Telescope, visit:

    http://www.nasa.gov/hubble

    For more on NASA’s Spitzer Space Telescope, visit:

    http://www.nasa.gov/spitzer

    See the full article here .

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

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

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

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

     
  • richardmitnick 9:18 am on November 6, 2016 Permalink | Reply
    Tags: , , , Supermassive Black Holes, Very Long Baseline Array (VLBA)   

    From Astronomy Now: “Galactic merger exposes supermassive black hole” 

    Astronomy Now bloc

    Astronomy Now

    4 November 2016
    No writer credit found

    1
    This NASA/ESA Hubble Space Telescope image of galaxy cluster ZwCl 8193 reveals the core of the giant galaxy 2MASX 17171926+4226571, the smaller galaxy and a trail of debris. The position of the giant galaxy’s core is marked by the white ‘+’ and optical identification of B3 1715+425 is enclosed by a white circle centred on its Hubble position. Image credit: J.J. Condon et al. / NASA / ESA / Hubble / NSF / VLBA.

    Astronomers using the super-sharp radio vision of the National Science Foundation’s Very Long Baseline Array (VLBA) have found the shredded remains of a galaxy that passed through a larger galaxy, leaving only the smaller galaxy’s nearly-naked supermassive black hole to emerge and speed away at more than 2,000 miles per second.

    NRAO VLBA
    NRAO/VLBA

    The galaxies are part of a cluster of galaxies more than 2 billion light-years from Earth. The close encounter, millions of years ago, stripped the smaller galaxy of nearly all its stars and gas. What remains is its black hole and a small galactic remnant only about 3,000 light-years across. For comparison, our Milky Way Galaxy is approximately 100,000 light-years across.

    The discovery was made as part of a program to detect supermassive black holes, millions or billions of times more massive than the Sun, that are not at the centres of galaxies. Supermassive black holes reside at the centres of most galaxies.

    Sag A*  NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    Large galaxies are thought to grow by devouring smaller companions. In such cases, the black holes of both are expected to orbit each other, eventually merging.

    “We were looking for orbiting pairs of supermassive black holes, with one offset from the centre of a galaxy, as telltale evidence of a previous galaxy merger,” said James Condon, of the National Radio Astronomy Observatory. “Instead, we found this black hole fleeing from the larger galaxy and leaving a trail of debris behind it,” he added.

    “We’ve not seen anything like this before,” Condon said.

    The astronomers began their quest by using the VLBA to make very high-resolution images of more than 1,200 galaxies, previously identified by large-scale sky surveys done with infrared and radio telescopes. Their VLBA observations showed that the supermassive black holes of nearly all these galaxies were at the centres of the galaxies.

    However, one object, in a cluster of galaxies called ZwCl 8193, did not fit that pattern. Further studies showed that this object, called B3 1715+425, is a supermassive black hole surrounded by a galaxy much smaller and fainter than would be expected. In addition, this object is speeding away from the core of a much larger galaxy, leaving a wake of ionised gas behind it.

    The scientists concluded that B3 1715+425 is what has remained of a galaxy that passed through the larger galaxy and had most of its stars and gas stripped away by the encounter — a “nearly naked” supermassive black hole.

    2
    Depiction on B3 1715+425

    The speeding remnant, the scientists said, probably will lose more mass and cease forming new stars.

    “In a billion years or so, it probably will be invisible,” Condon said. That means, he pointed out, that there could be many more such objects left over from earlier galactic encounters that astronomers can’t detect.

    The scientists will keep looking, however. They’re observing more objects, in a long-term project with the VLBA. Since their project is not time-critical, Condon explained, they use “filler time” when the telescope is not in use for other observations.

    “The data we get from the VLBA is very high quality. We get the positions of the supermassive black holes to extremely good precision. Our limiting factor is the precision of the galaxy positions seen at other wavelengths that we use for comparison,” Condon said. With new optical telescopes that will come on line in future years, such as the Large Synoptic Survey Telescope (LSST), he said, they will then have improved images that can be compared with the VLBA images.

    LSST/Camera, built at SLAC
    LSST/Camera, built at SLAC
    LSST Interior
    LSST telescope, currently under construction at Cerro Pachón Chile
    LSST telescope, currently under construction at Cerro Pachón Chile

    They hope that this will allow them to discover more objects like B3 1714+425.

    “And also maybe some of the binary supermassive black holes we originally sought,” he said.

    See the full article here .

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  • richardmitnick 5:18 am on June 25, 2016 Permalink | Reply
    Tags: , , , , , Supermassive Black Holes,   

    From Southampton: “Black holes and measuring gravitational waves” 

    U Southampton bloc

    University of Southampton

    16 June 2016
    No writer credit found

    1
    Artist’s concept of a supermassive black hole. Credit: NASA – JPL/Caltech

    The supermassive black holes found at the centre of every galaxy, including our own Milky Way, may, on average, be smaller than we thought, according to work led by astronomer Dr Francesco Shankar.

    Sag A*  NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    If he and his colleagues are right, then the gravitational waves produced when they merge will be harder to detect than previously assumed. The international team of scientists published their results in Monthly Notices of the Royal Astronomical Society.

    Supermassive black holes have been found lurking in the cores of all galaxies observed with high enough sensitivity. Despite this, little is known about how they formed. What is known is that the mass of a supermassive black hole at the centre of a galaxy is related to the total mass and the typical speeds (the “velocity dispersion”) of the stars in its host.

    The very existence of this relationship suggests a close co-evolution between black holes and their host galaxies, and understanding their origin is vital for a proper model of how galaxies and black holes form and evolve. This is because many galaxy evolution models invoke powerful winds and/or jets from the central supermassive black hole to control or even stop star formation in the host galaxy (so-called “quasar feedback”). Alternatively, multiple mergers of galaxies – and their central black holes – are also often suggested as the primary drivers behind the evolution of massive galaxies.

    Despite major theoretical and observational efforts in the last decades, it remains unclear whether quasar feedback actually ever occurred in galaxies, and to what extent mergers have truly shaped galaxies and their black holes.

    The new work shows that selection effects – where what is observed is not representative – have significantly biased the view of the local black hole population. This bias has led to significantly overestimated black hole masses. It suggests that modellers should look to velocity dispersion rather than stellar mass as the key to unlocking the decades-old puzzles of both quasar feedback and the history of galaxies.

    With less mass than previously thought, supermassive black holes have on average weaker gravitational fields. Despite this, they were still able to power quasars, making them bright enough to be observed over distances of billions of light years.

    Unfortunately, it also implies a substantial reduction in the expected gravitational wave signal detectable from pulsar timing array experiments. Ripples in spacetime that were first predicted by Albert Einstein in his general theory of relativity in 1915; gravitational waves were finally detected last year and announced by the LIGO team this February.

    LSC LIGO Scientific Collaboration
    Caltech/MIT Advanced aLigo Hanford, WA, USA installation
    Caltech/MIT Advanced aLigo Hanford, WA, USA installation
    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA
    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    The hope is that coming observatories can observe many more gravitational wave events, and that it will provide astronomers with a new technique for observing the universe.

    VIRGO Gravitational Wave interferometer, near Pisa, Italy
    VIRGO Gravitational Wave interferometer, near Pisa, Italy, not yet taking data.

    Dr Shankar comments: “Gravitational wave astronomy is opening up an entirely new way of observing the universe. Our results though illustrate how challenging a complete census of the gravitational background could be, with the signals from the largest black holes being paradoxically among the most difficult to detect with present technology.”

    Researchers expect pairs of supermassive black holes, found in merging galaxies, to be the strongest sources of gravitational waves in the universe.

    Cornell SXS team. Two merging black holes simulation
    Cornell SXS team. Two merging black holes simulation

    However, the more massive the pairs, the lower the frequencies of the emitted waves, which become inaccessible to ground based interferometers like LIGO. Gravitational waves from supermassive black holes can however be detected from space via dedicated gravitational telescopes (such as the present and future ESA missions LISA pathfinder and eLISA), or by a different method using ‘pulsar timing arrays’.

    ESA/LISA Pathfinder
    ESA/LISA Pathfinder

    ESA/eLISA
    ESA/eLISA

    These devices monitor the collapsed, rapidly rotating remnants of massive stars, which have pulsating signals. Even this method though is still a few years from making a detection, according to a follow-up study by the same team expected to appear in another Monthly Notices paper later this year.

    See the full article here .

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    U Southampton campus

    The University of Southampton is a world-class university built on the quality and diversity of our community. Our staff place a high value on excellence and creativity, supporting independence of thought, and the freedom to challenge existing knowledge and beliefs through critical research and scholarship. Through our education and research we transform people’s lives and change the world for the better.

    Vision 2020 is the basis of our strategy.

    Since publication of the previous University Strategy in 2010 we have achieved much of what we set out to do against a backdrop of a major economic downturn and radical change in higher education in the UK.

    Vision 2020 builds on these foundations, describing our future ambition and priorities. It presents a vision of the University as a confident, growing, outwardly-focused institution that has global impact. It describes a connected institution equally committed to education and research, providing a distinctive educational experience for its students, and confident in its place as a leading international research university, achieving world-wide impact.

     
  • richardmitnick 3:06 pm on May 24, 2016 Permalink | Reply
    Tags: , , , , Supermassive Black Holes   

    From Hubble: “Hubble finds clues to the birth of supermassive black holes” 

    NASA Hubble Banner

    NASA Hubble Telescope

    Hubble

    24 May 2016
    At ESA/Hubble
    Fabio Pacucci
    Scuola Normale Superiore
    Pisa, Italy
    Email: fabio.pacucci@sns.it

    Andrea Ferrara
    Scuola Normale Superiore
    Pisa, Italy
    Email: andrea.ferrara@sns.it

    Andrea Grazian
    National Institute for Astrophysics
    Rome, Italy
    Email: grazian@oa-roma.inaf.it

    Mathias Jäger
    ESA/Hubble, Public Information Officer
    Garching bei München, Germany
    Tel: +49 176 62397500
    Email: mjaeger@partner.eso.org

    At NASA/Chandra
    Media contacts:
    Felicia Chou / Sean Potter
    Headquarters, Washington
    202-358-0257 / 1536
    felicia.chou@nasa.gov / sean.potter@nasa.gov

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

    1

    Astrophysicists have taken a major step forward in understanding how supermassive black holes formed. Using data from Hubble and two other space telescopes, Italian researchers have found the best evidence yet for the seeds that ultimately grow into these cosmic giants.

    For years astronomers have debated how the earliest generation of supermassive black holes formed very quickly, relatively speaking, after the Big Bang. Now, an Italian team has identified two objects in the early Universe that seem to be the origin of these early supermassive black holes. The two objects represent the most promising black hole seed candidates found so far [1].

    The group used computer models and applied a new analysis method to data from the NASA Chandra X-ray Observatory, the NASA/ESA Hubble Space Telescope, and the NASA Spitzer Space Telescope to find and identify the two objects. Both of these newly discovered black hole seed candidates are seen less than a billion years after the Big Bang and have an initial mass of about 100 000 times the Sun.

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    NASA/Spitzer Telescope
    NASA/Spitzer Telescope

    “Our discovery, if confirmed, would explain how these monster black holes were born,” said Fabio Pacucci, lead author of the study, of Scuola Normale Superiore in Pisa, Italy.

    This new result helps to explain why we see supermassive black holes less than one billion years after the Big Bang.

    There are two main theories to explain the formation of supermassive black holes in the early Universe. One assumes that the seeds grow out of black holes with a mass about ten to a hundred times greater than our Sun, as expected for the collapse of a massive star. The black hole seeds then grew through mergers with other small black holes and by pulling in gas from their surroundings. However, they would have to grow at an unusually high rate to reach the mass of supermassive black holes already discovered in the billion years young Universe.

    The new findings support another scenario where at least some very massive black hole seeds with 100 000 times the mass of the Sun formed directly when a massive cloud of gas collapses [2]. In this case the growth of the black holes would be jump started, and would proceed more quickly.

    “There is a lot of controversy over which path these black holes take,” said co-author Andrea Ferrara also of Scuola Normale Superiore. “Our work suggests we are converging on one answer, where black holes start big and grow at the normal rate, rather than starting small and growing at a very fast rate.”

    Andrea Grazian, a co-author from the National Institute for Astrophysics in Italy explains: “Black hole seeds are extremely hard to find and confirming their detection is very difficult. However, we think our research has uncovered the two best candidates so far.”

    Even though both black hole seed candidates match the theoretical predictions, further observations are needed to confirm their true nature. To fully distinguish between the two formation theories, it will also be necessary to find more candidates.

    These results* will appear in the June 21st issue of the Monthly Notices of the Royal Astronomical Society and is available online. The authors of the paper are Fabio Pacucci (SNS, Italy), Andrea Ferrara (SNS), Andrea Grazian (INAF), Fabrizio Fiore (INAF), Emaneule Giallongo (INAF), and Simonetta Puccetti (ASI Science Data Center).

    The team plans to conduct follow-up observations in X-rays and in the infrared range to check whether the two objects have more of the properties expected for black hole seeds. Upcoming observatories, like the NASA/ESA/CSA James Webb Space Telescope and the European Extremely Large Telescope will certainly mark a breakthrough in this field, by detecting even smaller and more distant black holes.

    NASA/ESA/CSA Webb Telescope annotated
    NASA/ESA/CSA Webb Telescope annotated

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile
    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile

    Notes

    [1] Supermassive black holes contain millions or even billions of times the mass of the Sun. In the modern Universe they can be found in the centre of nearly all large galaxies, including the Milky Way.

    Sag A*  NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    The supermassive black hole in the centre of the Milky Way has a mass of four million solar masses. The two black hole seed candidates would also be the progenitors of two of the modern supermassive black holes.

    [2] Black hole seeds created through the collapse of a massive cloud of gas bypass any other intermediate phases such as the formation and subsequent destruction of a massive star.

    The team of scientists in this study consists of Fabio Pacucci (Scuola Normale Superiore, Italy), Andrea Ferrara (Scuola Normale Superiore, Italy), Andrea Grazian (INAF, Italy), Fabrizio Fiore (INAF, Italy), Emanuele Giallongo (INAF, Italy), Simonetta Puccetti (ASDC-ASI, Italy)

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

    NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington, D.C. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

    *Science paper:
    First Identification of Direct Collapse Black Hole Candidates in the Early Universe in CANDELS/GOODS-S

    See the full article here .

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    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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  • richardmitnick 11:48 am on April 26, 2016 Permalink | Reply
    Tags: , , , Supermassive Black Holes   

    From GIZMODO: “A Dozen Black Holes Are Mysteriously Spewing Energy In the Same Direction” 

    GIZMODO bloc

    GIZMODO

    4.25.16
    Maddie Stone

    NASA Chandra black hole poster
    NASA Chandra black hole poster

    Something strange is going on in a distant corner of our universe. About a dozen supermassive black holes are all shooting enormous jets of energy in roughly the same direction. It could be a cosmic coincidence—but some astronomers suspect there are larger forces at play.

    Supermassive black holes, which are found at the center of nearly all galaxies, periodically erupt, hurling streams of energized plasma into intergalactic space. For instance our galaxy’s own supermassive black hole, Sagittarius A*, will sometimes swallow a star and belch x-ray energy all over the Milky Way.

    Sag A* NASA's Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA’s Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    These eruptions are fascinating to astronomers, but they are typically thought to be independent events.

    Now, a survey of 64 galaxies located halfway across the known universe has revealed a bizarre alignment between the energy jets erupting from a handful of black holes, all of which are located within a hundred million light years of each other. A pattern like this shouldn’t exist, unless it’s being dictated by an even larger structure in our universe.

    Which is exactly what Russ Taylor, lead author of a forthcoming study* in the Monthly Notices of the Royal Astronomical Society, thinks may be happening. As Science News reports, Taylor suspects the eruptions are all being steered by filaments, a sort of scaffolding along which matter congregates on a cosmic scale. If the hypothesis is correct, it could help explain how our universe’s present structure came to be.

    Not everybody is convinced, however. Some astronomers feel the number of galaxies in the study is too small to draw meaningful conclusions, and that the pattern could be chalked up to nothing more than chance. But the idea of a cosmic alignment is intriguing enough that Taylor and his colleagues plan to follow up on it by probing more black holes, and by figuring out the precise distances between the galaxies they’ve already studied.

    I suppose if there’s one takeaway for us puny Earthlings, it’s that there are mind-bogglingly vast forces shaping our universe in ways we’ve only just begun to understand. Keeps your Monday struggle in perspective.

    *Science paper
    Alignments of radio galaxies in deep radio imaging of ELAIS N1

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  • richardmitnick 2:09 pm on April 2, 2016 Permalink | Reply
    Tags: , , , Supermassive Black Holes   

    From SPACE.com: “Cataclysm Hunters: The Search for Monster Black-Hole Collisions” 

    space-dot-com logo

    SPACE.com

    April 1, 2016
    Sarah Lewin

    1
    Supermassive black holes at the heart of merging galaxies will circle closer and closer until they come together, releasing a titanic wave of energy. The process may help explain how black holes get so huge to begin with. Credit: NASA

    Julie Comerford has built a career searching for galaxies that contain not one, but two supermassive black holes — light-devouring monsters that have masses millions or billions of times that of the sun. So far, the count is up to 12.

    “The mergers of two supermassive black holes is second only to the Big Bang as the most energetic phenomena in the universe,” Comerford, an astrophysicist at the University of Colorado, Boulder, told Space.com. Yet that titanic, violent dance — essential to galaxy growth and evolution — has not been spotted very often.

    Each galaxy has a supermassive black hole at its core. When two galaxies merge, the two central black holes circle faster and faster, coming closer and closer until they merge into one as well.

    Cornell SXS team. Two merging black holes simulation
    Cornell SXS team. Two merging black holes simulation

    Black holes merging Swinburne Astronomy Productions
    Black holes merging Swinburne Astronomy Productions

    Once light crosses the threshold of a black hole, it can never escape, but galactic sleuths like Comerford have spent years looking for other kinds of evidence revealing those monster black holes headed for a cataclysmic collision.

    Relatively small “stellar mass” black holes form when a huge star dies in a supernova explosion and its core collapses. A black hole can grow as more mass falls into it, but nobody can fully explain how the supermassive ones lurking at the cores of galaxies are able to get so enormous — the one at the center of the Milky Way has a mass 4 million times that of the sun, and it’s comparatively small.

    Sag A* NASA's Chandra X-Ray Observatory 23 July 2014
    Sag A* NASA’s Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    The process of two galaxies merging could explain this extraordinary growth.

    “One theory is that maybe a lot of the black hole mass growth actually occurs during galaxy mergers, because that’s when all this gas is being slammed together and funneled towards a black hole — so there’s a lot of fuel available for the black hole to eat and build up its mass,” Comerford said.

    Solving the growth mystery promises to reveal insight into how galaxies, and the black holes at their hearts, grow and change over time. Plus, it should help hone scientists’ newly proven powers of detecting gravitational waves.

    Searching for light

    The ultralarge black holes at the centers of galaxies don’t let any light slip out, but pairs of structures so massive leave their mark on the environment around them in other ways. For one thing, they’re always at the hearts of merging galaxies.

    “The Milky Way just has one central big sphere of stars, so it would not be a good candidate for one of these potential double black holes,” Comerford said. “We’re looking for things that look different from the usual galaxies that you see images of, like a normal spiral galaxy or elliptical galaxy — that’s not what we want. [We want] the ones that look like they’re two merging spheres of stars.”

    That merging process also puts a lot of extra material in the path of each of the black holes, which can gain whirling “accretion disks” of dust around them that glow brightly andemit jets of energy. Supermassive black holes with that kind of ultrabright beacon are called quasars, and they’re far from invisible — in fact, they often outshine the galaxies that surround them.

    2
    This artist’s concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below. Credit: NASA/ESA

    NASA/ESA Hubble Telescope
    NASA/ESA Hubble Telescope

    Comerford first started searching for these double-black-hole galaxies when she was in graduate school. Her group first recognized the black holes by the unusual spectrum of light their host galaxies emit, as measured in big survey studies like the Sloan Digital Sky Survey [SDSS].

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

    Galaxies with a quasar at their center — a supermassive black hole taking in large quantities of material — emit a narrow band of radiation that’s very bright. But the galaxies Comerford was looking for were more complex: Instead of a nice, tall peak indicating the intense glow emitted by the quasar, she saw two peaks — one slightly redder and one slightly bluer.

    The two peaks showed that there were two significant light sources in the system: one moving toward Earth and one moving away. By following up with an X-ray or radio telescope, or with NASA’s Hubble Space Telescope looking in visible light, she could verify that those two light sources were embedded in a merging set of galaxies.

    Comerford’s systematic search could find supermassive black holes that are around 3,000 light-years away from each other — that’s about 1/8 the distance from Earth’s solar system to the center of the galaxy — and that are orbiting one another at about 500,000 mph (800,000 kph). Looking straight at such systems, it might be impossible to distinguish the two quasars from each other because they’d be too close together, so the wavelengths of light emitted provided a crucial first clue.

    More recently, because of the increasing amount of Hubble galaxy imagery available, Comerford has started relying on visual images to pinpoint the supermassive black hole pairs. First, she finds quasar activity in telescope data, and then she checks with a Hubble image of the galaxy to see if it looks like it might be two merging galaxies, with two tight cores of stars that might each surround a supermassive black hole. Finally, she follows up with higher-resolution infrared or radio telescopes to try and distinguish whether there are two separate quasars there.

    4
    Diagrams of 30 merging galaxies. The edges show signal strength from carbon monoxide, while colors show where the gas is moving. Red represents gas moving away from Earth, and blue moving towards.
    Credit: ALMA (ESO/NAOJ/NRAO)/SMA/CARMA/IRAM/J. Ueda et al.

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array

    CfA Submillimeter Array Hawaii SAO
    CfA Submillimeter Array Hawaii SAO

    CARMA Array no longer in service
    CARMA Array no longer in service

    IRAM NOEMA interferometer
    IRAM NOEMA interferometer

    “There may be one [supermassive black hole pair] in every something like a thousand to a million galaxies,” Sarah Spolaor, a researcher at the National Radio Astronomy Observatory in New Mexico, told Space.com. “The chance of just finding one by chance is pretty low, but if you have a sky catalog of thousands upon thousands of galaxies, then you’re much more likely to see that kind of weird-looking one that you think, ‘What is that?’ — and it’s maybe a binary black hole.”

    The growing mystery

    Researchers know that supermassive black holes are intimately tied to the galaxies surrounding them. There’s one at every galaxy’s heart, and the galaxy’s size is reflected in the size of the black hole. Even early galaxies, born close to the beginning of the universe, show that correlation. Finding black hole mergers can help solve the mystery of how those black holes got so big, so early in the universe’s history. Plus, even the existence of quasars at all, which can only form once black holes get massive enough, raises questions.

    “Why are we doing this stamp collecting?” Comerford said. “There’s scientific questions that we want to answer, and that is one of the big ones: how do black holes get enough gas in the first place to become a quasar?”

    Researchers know that black holes at the center of merging galaxies ultimately form into one larger supermassive black hole, but it’s unclear whether that’s the whole picture.

    “Galaxy mergers are definitely an effective way to get supermassive black holes to grow,” said Scott Barrows, an astronomer also at the University of Colorado, Boulder. “But how important is this process relative to other processes that could just be happening in a galaxy that’s not interacting?” Barrows said. “There’s not a good consensus on how this works as of yet,” he told Space.com.

    Barrows’ own research searches for supermassive black hole systems where only one black hole has bloomed into a quasar — an indicator, he said, that the black holes are uneven; one is growing faster than the other and taking in more material kicked up in the merger. That uneven matchup could help scientists understand exactly what role the events play in growing black holes and the galaxies surrounding them.

    Besides solving that mystery, a better understanding of the epic systems should reveal more about the overall universe’s evolution, researchers say.

    “Supermassive black holes are thought to play a huge role in how the universe evolves,” Spolaor said. “They are the most massive compact single objects in the universe.”

    See the full article here .

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  • richardmitnick 2:04 pm on January 12, 2016 Permalink | Reply
    Tags: , , , Supermassive Black Holes,   

    From Symmetry: “Black holes” 

    Symmetry

    01/12/16
    Ali Sundermier

    Let yourself be pulled into the weird world of black holes.

    Temp 1

    Imagine, somewhere in the galaxy, the corpse of a star so dense that it punctures the fabric of space and time. So dense that it devours any surrounding matter that gets too close, pulling it into a riptide of gravity that nothing, not even light, can escape.

    And once matter crosses over the point of no return, the event horizon, it spirals helplessly toward an almost infinitely small point, a point where spacetime is so curved that all our theories break down: the singularity. No one gets out alive.

    Black holes sound too strange to be real. But they are actually pretty common in space. There are dozens known and probably millions more in the Milky Way and a billion times that lurking outside. Scientists also believe there could be a supermassive black hole at the center of nearly every galaxy, including our own. The makings and dynamics of these monstrous warpings of spacetime have been confounding scientists for centuries.

    A history of black holes

    It all started in England in 1665, when an apple broke from the branch of a tree and fell to the ground. Watching from his garden at Woolsthorpe Manor, Isaac Newton began thinking about the apple’s descent: a line of thought that, two decades later, ended with his conclusion that there must be some sort of universal force governing the motion of apples and cannonballs and even planetary bodies. He called it gravity.

    Newton realized that any object with mass would have a gravitational pull. He found that as mass increases, gravity increases. To escape an object’s gravity, you would need to reach its escape velocity. To escape the gravity of Earth, you would need to travel at a rate of roughly 11 kilometers per second.

    It was Newton’s discovery of the laws of gravity and motion that, 100 years later, led Reverend John Michell, a British polymath, to the conclusion that if there were a star much more massive or much more compressed than the sun, its escape velocity could surpass even the speed of light. He called these objects “dark stars.” Twelve years later, French scientist and mathematician Pierre Simon de Laplace arrived at the same conclusion and offered mathematical proof for the existence of what we now know as black holes.

    In 1915, Albert Einstein set forth the revolutionary theory of general relativity, which regarded space and time as a curved four-dimensional object. Rather than viewing gravity as a force, Einstein saw it as a warping of space and time itself. A massive object, such as the sun, would create a dent in spacetime, a gravitational well, causing any surrounding objects, such as the planets in our solar system, to follow a curved path around it.

    A month after Einstein published this theory, German physicist Karl Schwarzschild discovered something fascinating in Einstein’s equations. Schwarzschild found a solution that led scientists to the conclusion that a region of space could become so warped that it would create a gravitational well that no object could escape.

    Up until 1967, these mysterious regions of spacetime had not been granted a universal title. Scientists tossed around terms like “collapsar” or “frozen star” when discussing the dark plots of inescapable gravity. At a conference in New York, physicist John Wheeler popularized the term “black hole.”

    How to find a black hole

    During star formation, gravity compresses matter until it is stopped by the star’s internal pressure. If the internal pressure does not stop the compression, it can result in the formation of a black hole.

    Some black holes are formed when massive stars collapse. Others, scientists believe, were formed very early in the universe, a billion years after the big bang.

    There is no limit to how immense a black hole can be, sometimes more than a billion times the mass of the sun. According to general relativity, there is also no limit to how small they can be (although quantum mechanics suggests otherwise). Black holes grow in mass as they continue to devour their surrounding matter. Smaller black holes accrete matter from a companion star while the larger ones feed off of any matter that gets too close.

    Black holes contain an event horizon, beyond which not even light can escape. Because no light can get out, it is impossible to see beyond this surface of a black hole. But just because you can’t see a black hole, doesn’t mean you can’t detect one.

    Scientists can detect black holes by looking at the motion of stars and gas nearby as well as matter accreted from its surroundings. This matter spins around the black hole, creating a flat disk called an accretion disk. The whirling matter loses energy and gives off radiation in the form of X-rays and other electromagnetic radiation before it eventually passes the event horizon.

    This is how astronomers identified Cygnus X-1 in 1971. Cygnus X-1 was found as part of a binary star system in which an extremely hot and bright star called a blue supergiant formed an accretion disk around an invisible object. The binary star system was emitting X-rays, which are not usually produced by blue supergiants. By calculating how far and fast the visible star was moving, astronomers were able to calculate the mass of the unseen object. Although it was compressed into a volume smaller than the Earth, the object’s mass was more than six times as heavy as our sun.

    Several different experiments study black holes. The Event Horizon Telescope [EHT] will look at black holes in the nucleus of our galaxy and a nearby galaxy, M87. Its resolution is high enough to image flowing gas around the event horizon.

    Event Horizon Telescope map
    EHT

    Scientists can also do reverberation mapping, which uses X-ray telescopes to look for time differences between emissions from various locations near the black hole to understand the orbits of gas and photons around the black hole.

    The Laser Interferometer Gravitational-Wave Observatory, or LIGO, seeks to identify the merger of two black holes, which would emit gravitational radiation, or gravitational waves, as the two black holes merge.

    Caltech Ligo
    MIT/Caltech Advanced LIGO

    In addition to accretion disks, black holes also have winds and incredibly bright jets erupting from them along their rotation axis, shooting out matter and radiation at nearly the speed of light. Scientists are still working to understand how these jets form.

    What we don’t know

    Scientists have learned that black holes are not as black as they once thought them to be. Some information might escape them. In 1974, Stephen Hawking published results that showed that black holes should radiate energy, or Hawking radiation.

    Matter-antimatter pairs are constantly being produced throughout the universe, even outside the event horizon of a black hole. Quantum theory predicts that one particle might be dragged in before the pair has a chance to annihilate, and the other might escape in the form of Hawking radiation. This contradicts the picture general relativity paints of a black hole from which nothing can escape.

    But as a black hole radiates Hawking radiation, it slowly evaporates until it eventually vanishes. So what happens to all the information encoded on its horizon? Does it disappear, which would violate quantum mechanics? Or is it preserved, as quantum mechanics would predict? One theory is that the Hawking radiation contains all of that information. When the black hole evaporates and disappears, it has already preserved the information of everything that fell into it, radiating it out into the universe.

    Black holes give scientists an opportunity to test general relativity in very extreme gravitational fields. They see black holes as an opportunity to answer one of the biggest questions in particle physics theory: Why can’t we square quantum mechanics with general relativity?

    Beyond the event horizon, black holes curve into one of the darkest mysteries in physics. Scientists can’t explain what happens when objects cross the event horizon and spiral towards the singularity. General relativity and quantum mechanics collide and Einstein’s equations explode into infinities. Black holes might even house gateways to other universes called wormholes and violent fountains of energy and matter called white holes, though it seems very unlikely that nature would allow these structures to exist.

    Sometimes reality is stranger than fiction.

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 6:46 am on January 9, 2016 Permalink | Reply
    Tags: , , , Supermassive Black Holes   

    From ESA: “Supermassive and super-hungry” 

    ESASpaceForEuropeBanner
    European Space Agency

    08/01/2016
    No writer credit found

    1
    NASA/ESA Hubble and S. Smartt (Queen’s University Belfast)

    This NASA/ESA Hubble Space Telescope image shows the spiral galaxy NGC 4845, located over 65 million light-years away in the constellation of Virgo (The Virgin). The galaxy’s orientation clearly reveals the galaxy’s striking spiral structure: a flat and dust-mottled disc surrounding a bright galactic bulge.

    NASA Hubble Telescope
    NASA/ESA Hubble

    NGC 4845’s glowing centre hosts a gigantic version of a black hole, known as a supermassive black hole. The presence of a black hole in a distant galaxy like NGC 4845 can be inferred from its effect on the galaxy’s innermost stars; these stars experience a strong gravitational pull from the black hole and whizz around the galaxy’s centre much faster than otherwise.

    From investigating the motion of these central stars, astronomers can estimate the mass of the central black hole — for NGC 4845 this is estimated to be hundreds of thousands times heavier than the Sun. This same technique was also used to discover the supermassive black hole at the centre of our own Milky Way — Sagittarius A* — which hits some four million times the mass of the Sun (potw1340a).

    2
    Sagittarius A*. This image was taken with NASA’s Chandra X-Ray Observatory. Ellipses indicate light echoes.

    NASA Chandra Telescope
    NASA/Chandra

    3
    This image, not unlike a pointillist painting, shows the star-studded centre of the Milky Way towards the constellation of Sagittarius. The crowded centre of our galaxy contains numerous complex and mysterious objects that are usually hidden at optical wavelengths by clouds of dust — but many are visible here in these infrared observations from Hubble.
    However, the most famous cosmic object in this image still remains invisible: the monster at our galaxy’s heart called Sagittarius A*. Astronomers have observed stars spinning around this supermassive black hole (located right in the centre of the image), and the black hole consuming clouds of dust as it affects its environment with its enormous gravitational pull.
    Infrared observations can pierce through thick obscuring material to reveal information that is usually hidden to the optical observer. This is the best infrared image of this region ever taken with Hubble, and uses infrared archive data from Hubble’s Wide Field Camera 3, taken in September 2011. It was posted to Flickr by Gabriel Brammer, a fellow at the European Southern Observatory based in Chile. He is also an ESO photo ambassador. Credit: NASA/ESA Hubble and G. Brammer

    The galactic core of NGC 4845 is not just supermassive, but also super-hungry. In 2013 researchers were observing another galaxy when they noticed a violent flare at the centre of NGC 4845. The flare came from the central black hole tearing up and feeding off an object many times more massive than Jupiter. A brown dwarf or a large planet simply strayed too close and was devoured by the hungry core of NGC 4845.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 1:02 pm on January 5, 2016 Permalink | Reply
    Tags: , , Supermassive Black Holes,   

    From U Colorado: “Galactic merger reveals an unusual star-deprived black hole” 

    U Colorado

    University of Colorado Boulder

    January 5, 2016
    Julie Comerford, 303-242-2181
    julie.comerford@colorado.edu

    Trent Knoss, CU-Boulder media relations, 303-735-0528
    trent.knoss@colorado.edu

    1
    Image of the galaxy SDSS J1126+2944 taken with the Hubble Space Telescope and the Chandra X-ray Observatory. The arrow points to the black hole that lost most of its stars due to gravitational stripping processes.

    In a season of post-holiday gym memberships, an unusually star-deprived black hole at the site of two merged galaxies is showing that these massive gravitational voids can shed weight too.

    The recently discovered black hole, which does not have the expected number of stars surrounding it, could provide new insight into black hole evolution and behavior, according to recently published research from the University of Colorado Boulder.

    The findings were announced today during a news briefing at the annual meeting of the American Astronomical Society (AAS) being held this week in Kissimmee, Florida.

    Supermassive black holes exist at the centers of all massive galaxies, including the Milky Way, and contain a mass of between 1 million and 1 billion times that of the sun. The mass of a black hole tends to scale with the mass of its galaxy, and each black hole is typically embedded within a large sphere of stars.

    The galaxy SDSS J1126+2944 is the result of a merger between two smaller galaxies, which brought together a pair of supermassive black holes. One of the black holes is surrounded by a typical amount of stars, but the other black hole is strangely “naked” and has a much lower number of associated stars than expected.

    “One black hole is starved of stars, and has 500 times fewer stars associated with it than the other black hole,” said Julie Comerford, an assistant professor in CU-Boulder’s Department of Astrophysical and Planetary Sciences and the lead investigator of the new research. “The question is why there’s such a discrepancy.”

    One possibility, said Comerford, is that extreme gravitational and tidal forces simply stripped away most of the stars from one of the black holes over the course of the galactic merger.

    The other possibility, however, is that the merger actually reveals a rare “intermediate” mass black hole, with a mass of between 100 and 1 million times that of the sun. Intermediate mass black holes are predicted to exist at the centers of dwarf galaxies and thus have a lower number of associated stars. These intermediate mass black holes can grow and one day become supermassive black holes.

    “Theory predicts that intermediate black holes should exist, but they are difficult to pinpoint because we don’t know exactly where to look,” said Scott Barrows, a postdoctoral researcher at CU-Boulder who co-authored the study. “This unusual galaxy may provide a rare glimpse of one of these intermediate mass black holes.”

    If galaxy SDSS J1126+2944 does indeed contain an intermediate black hole, it would provide researchers with an opportunity to test the theory that supermassive black holes evolve from these lower-mass ‘seed’ black holes.

    Images of the galaxy SDSS J1126+2944 were taken with the Hubble Space Telescope and the Chandra X-ray Observatory, a NASA-operated orbital X-ray telescope.

    NASA Hubble Telescope
    NASA/ESA Hubble

    NASA Chandra Telescope
    NASA/Chandra

    Details of the research were recently published in The Astrophysical Journal. The article is also publicly available at arXiv.

    See the full article here .

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    U Colorado Campus

    As the flagship university of the state of Colorado, CU-Boulder is a dynamic community of scholars and learners situated on one of the most spectacular college campuses in the country. As one of 34 U.S. public institutions belonging to the prestigious Association of American Universities (AAU) – and the only member in the Rocky Mountain region – we have a proud tradition of academic excellence, with five Nobel laureates and more than 50 members of prestigious academic academies.

    CU-Boulder has blossomed in size and quality since we opened our doors in 1877 – attracting superb faculty, staff, and students and building strong programs in the sciences, engineering, business, law, arts, humanities, education, music, and many other disciplines.

    Today, with our sights set on becoming the standard for the great comprehensive public research universities of the new century, we strive to serve the people of Colorado and to engage with the world through excellence in our teaching, research, creative work, and service.

     
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