Stig Östlund

torsdag, september 29, 2011

Space Telescopes Reveal Secrets of Turbulent Black Hole


An international team of astronomers using five different telescopes has uncovered striking features around a supermassive black hole in the core of the distant galaxy Markarian 509. They found a very hot corona hovering above the black hole and cold gas "bullets" in hotter diffuse gas, speeding outward with velocities over 1 million miles per hour. This corona absorbs and reprocesses the ultraviolet light from the accretion disk encircling the black hole, energizing it and converting it into X-rays. This discovery allows astronomers to make sense of some of the observations of active galaxies that have been hard to explain so far.

The heart of the campaign consisted of repeated visible, X-ray, and gamma-ray observations with ESA's XMM-Newton and INTEGRAL satellites, which monitored Markarian 509 for six weeks. This was followed by long observations with NASA's Chandra X-ray Observatory and the Hubble Space Telescope. Prior to these observations short snapshots to monitor the behavior of the source at all wavelengths were taken with NASA's Swift satellite. The combined efforts of all these instruments gave astronomers an unprecedented insight into the core of an active galaxy.

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