The Galactic Bulge Survey

The images linked below show some of the tools that we use to identify optical stars related to an X-ray source. First, we use the accurate astrometry provided by the Chandra satellite. Next we make use of the three color information provide by our optical data to select those sources which have an H_alpha excees. Note, however, that not all sources of interest have such an excess since some sources are H-poor (e.g. ultra-compact X-ray binaries). Finally, we obtain classification spectra of all optical counterparts to the X-ray sources. In the case linked above the source is a Cataclysmic Variable showing a strong H_alpha emission peak.