The galactic center: An interacting system of unusual sources
The region bounded by the inner tens of light-years at the center of the Milky Way Galaxy contains five principal components that coexist within the central deep well of gravitational potential. These constituents are a black hole candidate (Sgr A*) with a mass equivalent to 2.6 +/- 0.2 x 10(6) solar masses, a surrounding cluster of evolved stars, a complex of young stars, molecular and ionized gas clouds, and a powerful supernova-like remnant. The interaction of these components is responsible for many of the phenomena occurring in this complex and unique portion of the Galaxy. Developing a consistent picture of the primary interactions between the components at the Galactic center will improve our understanding of the nature of galactic nuclei in general, and will provide us with a better-defined set of characteristics of black holes. For example, the accretion of stellar winds by Sgr A* appears to produce far less radiation than indicated by estimates based on models of galactic nuclei.
Yusef-Zadeh
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Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA. E-mail: zadeh@nwu.edu. Department of Physics and Steward Observatory, The University of Arizona, Tucson, AZ 85721, USA. E-mail: melia@as.arizona.edu. S.
Melia
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Wardle
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