Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2001 May 16
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

The Centre of the Circinus Galaxy in X-Rays
Credit: F. Bauer (Penn State) et al., Chandra, NASA

Explanation: Are black holes the cause of X-rays that pour out from the centre of the Circinus galaxy? A new high-resolution image from the orbiting Chandra X-ray Observatory has resolved the inner regions of this nearby galaxy into several smaller sources. The image is shown above in representative-colour. Extended X-ray emission from the centre appears to match optical light and appears consistent with a model where hot gas is escaping from a supermassive black hole at Circinus' centre. At least one of the other sources varies its X-ray brightness as expected from a binary star system, indicating that the system is small yet massive, and giving credence to a model where a black hole is surrounded by doughnut-shaped ring. The region shown spans about 5000 light-years across.

Tomorrow's picture: Solar Neutrino Astronomy

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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