Friday, March 27, 2009

Erratic Black Hole Regulates Itself

This optical and infrared image from the Digitized Sky Survey shows the crowded field around the micro-quasar GRS 1915+105 (GRS 1915 for short) located near the plane of our Galaxy. The inset shows a close-up of the Chandra image of GRS 1915, one of the brightest X-ray sources in the Milky Way galaxy. (Credit: X-ray (NASA/CXC/Harvard/J.Neilsen); Optical & IR (Palomar DSS2))

From Science Daily:

ScienceDaily (Mar. 26, 2009) — New results from NASA's Chandra X-ray Observatory have made a major advance in explaining how a special class of black holes may shut off the high-speed jets they produce. These results suggest that these black holes have a mechanism for regulating the rate at which they grow.

Black holes come in many sizes: the supermassive ones, including those in quasars, which weigh in at millions to billions of times the mass of the Sun, and the much smaller stellar-mass black holes which have measured masses in the range of about 7 to 25 times the Sun's mass. Some stellar-mass black holes launch powerful jets of particles and radiation, like seen in quasars, and are called "micro-quasars".

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