NASA's Swift Finds 'Missing' Active Galaxies

Credits

• Animators

  • Scott Wiessinger (KBR Wyle Services, LLC) [Lead]
  • Chris Smith (KBR Wyle Services, LLC)
  • Donna Cox (AVL NCSA/University of Illinois)
  • Michael McClare (KBR Wyle Services, LLC)

• Graphics

  • Francis Reddy (University of Maryland College Park)

• Science writer

  • Francis Reddy (University of Maryland College Park) [Lead]

• Video editor

  • Scott Wiessinger (KBR Wyle Services, LLC)

• Scientists

  • Davide Burlon (Max Planck Institute for Extraterrestrial Physics)
  • Marco Ajello (SLAC National Accelerator Laboratory)

• Producer

  • Scott Wiessinger (KBR Wyle Services, LLC)

• Narrator

  • Scott Wiessinger (KBR Wyle Services, LLC)

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    ID: 11482 Produced Video

    The Cloudy Cores of Active Galaxies

    Feb. 19th, 2014
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    At the hearts of most big galaxies, including our own Milky Way, there lurks a supermassive black hole weighing millions to billions of times the sun's mass. As gas falls toward a supermassive black hole, it gathers into a so-called accretion disk and becomes compressed and heated, ultimately emitting X-rays. The centers of some galaxies produce unusually powerful emission that exceeds the sun's energy output by billions of times. These are active galactic nuclei, or AGN.Using data from NASA's Rossi X-ray Timing Explorer (RXTE) satellite, an international team has uncovered a dozen instances where X-ray signals from active galaxies dimmed as a result of a cloud of gas moving across our line of sight. The new study triples the number of cloud events previously identified in the 16-year archive.The study is the first statistical survey of the environments around supermassive black holes and is the longest-running AGN-monitoring study yet performed in X-rays. Scientists determined various properties of the occulting clouds, which vary in size and shape but average 4 billion miles (6.5 billion km) across – greater than Pluto's distance from the sun — and twice the mass of Earth. They orbit a few light-weeks to a few light-years from the black hole. ||

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