On the Chandra Detection of Diffuse X-ray Emission from Sgr A*

Martin Pessah1 and Fulvio Melia1,2

1 Steward Observatory, The University of Arizona
2 Physics Department, The University of Arizona

E-mail contact:melia@physics.arizona.edu

Kinematic studies of the stellar motions near Sgr A* have revealed the presence of several million solar masses of dark matter enclosed within 0.015 parsecs of the Galactic center. It is not yet clear, however, what precise fraction of this material is contained within a single point-like object, as opposed to a compact distribution of orbiting matter, e.g., in the form of neutron stars. Recently, Chandra observations of this region may have provided an important clue that can be used to at least set some constraints on this mass partitioning. It appears that a portion of the X-ray flux from Sgr A* is diffuse in nature. This may represent a contribution from captured gas at the Bondi-Hoyle radius, or it may actually be the spectral component produced by a cluster of relatively inert stars accreting from the gas falling toward the black hole. In this talk, we will discuss the physical issues that must be addressed by a study of this kind, and summarize the best results that one can achieve with the current set of observations.