Article Posted on : - Mar 27, 2009

NASA image

WASHINGTON (BNS): NASA’s Chandra X-rays image from the Digitised Sky Survey shows the crowded field around the micro-quasar GRS 1915+105 (GRS 1915 short) located near plane of the Galaxy. According to NASA, since 1999, with its High Energy Transmission Grating, Chandra has observed GRS 1915 eleven times.

A close- up image of GRS 1915, one of the brightest X-ray sources in the Milky Way galaxy, reveals the micro-quasar, which contains a black hole about 14 times the mass of the Sun that is feeding off material from a nearby companion star. “As the material swirls toward the black hole, an accretion disk forms. Powerful jets have also been observed in radio images of this system, along with remarkably unpredictable and complicated variability ranging from time-scales of seconds to months,” NASA said.

Studies by scientists reveal that the jet in GRS 1915 may be periodically choked off when a hot wind, seen in X-rays, is driven off the accretion disk around the black hole. The wind is believed to shut down the jet by depriving it of matter that would have otherwise fuelled it, NASA said.

The scientists said that once the wind dies down, the jet could re-emerge. “These results suggest that these black holes have a mechanism for regulating the rate at which they grow. Self-regulation is a common topic when discussing super-massive black holes, but this is the first clear evidence for it in a system containing a stellar-mass black hole,” NASA said.