Monitoring the X-ray Sources in the Bulge of M31
Abstract
We present the first results of our program to monitor the x-ray sources in the bulge of M31. The program includes observations made with the ROSAT HRI, together with nearly simultaneous radio and optical observations. Results from two ~ 25 ksec HRI observations, taken in July 1994, will be discussed here. We present new x-ray source lists and updated globular cluster identifications. Comparison of x-ray intensities from the current epoch with those obtained from similar observations taken in 1990 indicates that a number of x-ray sources varied significantly in the interim. We use current results and those from the earlier ROSAT and Einstein HRI observations to estimate the rate of x-ray transients in M31. Among the sources observed to vary is the x-ray source associated with the nucleus of M31. This source is of particular interest because of the discovery of an unresolved nuclear radio source (Crane, Dickel & Cowan 1992, ApJ Letters, 390, L9), and we discuss the status of our VLA observational program on the nuclear x-ray source, as well as on other x-ray sources within ~ 3(') of the nucleus. Finally, we briefly discuss our H_α observations of the M31 bulge.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1994
- Bibcode:
- 1994AAS...18510210P