Look at this new picture of Sagittarius A, the black hole at the center of our galaxy: It's alive with starlight. Sagittarius A eats much less stellar matter than a normal black hole, and this image provides a clue why.
According to the Chandra Observatory, Sagittarius devours only about one percent as much stellar matter as you would expect, and the close observation that resulted in this image may explain this discrepancy:
Why does it consume so little? The answer may be found in a new theoretical model developed using data from a very deep exposure made by NASA's Chandra X-ray Observatory. This model considers the flow of energy between two regions around the black hole: an inner region that is close to the so-called event horizon (the boundary beyond which even light cannot escape), and an outer region that includes the black hole's fuel source - the young stars - extending up to a million times farther out. Collisions between particles in the hot inner region transfer energy to particles in the cooler outer region via a process called conduction. This, in turn, provides additional outward pressure that makes nearly all of the gas in the outer region flow away from the black hole. The model appears to explain well the extended shape of hot gas detected around Sgr A* in X-rays as well as features seen in other wavelengths.
See the full image, in insanely high res, over at the link. [Chandra]
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