Chandra X-ray observations of galaxies in an off-center region of the Coma Cluster

We have performed a pilot Chandra survey of an off-center region of the Coma Cluster to explore the X-ray properties and luminosity function of normal galaxies. We present results on 13 Chandra-detected galaxies with optical photometric matches, including four spectroscopically confirmed Coma-member galaxies. All seven spectroscopically confirmed giant Coma galaxies in this field have detections or limits consistent with low X-ray to optical flux ratios [(f(X)/f(R)) < 10(-3)]. We do not have sufficient numbers of X-ray-detected galaxies to directly measure the galaxy X-ray luminosity function (XLF). However, since we have a well-measured optical LF, we take this low X-ray to optical flux ratio for the seven spectroscopically confirmed galaxies to translate the optical LF to an XLF. We find good agreement with Finoguenov et al. (2004), indicating that the X-ray emission per unit optical flux per galaxy is suppressed in clusters of galaxies, but we extend this work to a specific off-center environment in the Coma Cluster. Finally, we report the discovery of a region of diffuse X-ray flux that might correspond to a small group interacting with the Coma intracluster medium (ICM).