Credit: ESA/UCSB/R. Shirley

X-ray Census in Andromeda

The Andromeda Galaxy (also known as M31) is a close neighbor to the Milky Way (only 2.6 million light years away!). The Andromeda is a favorite object of astronomers, and X-ray astronomers in particular, since it's easier to determine the position and spatial distributions of stars and gas in the galaxy. Because Andromeda is distant, good spatial resolution and sensitivity is needed to detect sources in Andromeda clearly. The XMM-Newton X-ray observatory has recently observed the Andromeda, and taken a "census" of the bright sources of X-ray emission. The image above of the center of the Andromeda galaxy was obtained in a 10 hour exposure with XMM-Newton's EPIC camera. The bright points of X-ray light are probably X-ray binaries powered by the accretion of star matter onto a neutron star (or black hole). The EPIC image also shows faint diffuse emission near the center of the galaxy which apparently is not related to point sources like stars or binaries, and probably which represents diffuse hot gas produced over millions of years by exploding stars called supernovae. Astronomers hope that by studying the diffuse X-ray gas they can reconstruct the number of stars which must have exploded in Andromeda

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Each week the HEASARC brings you new, exciting and beautiful images from X-ray and Gamma ray astronomy. Check back each week and be sure to check out the HEAPOW archive!

Page Author: Dr. Michael F. Corcoran
Last modified January 26, 2001