AAS 199th meeting, Washington, DC, January 2002
Session 130. Surveys, Surveys
Display, Thursday, January 10, 2002, 9:20am-4:00pm, Exhibit Hall

## [130.06] Chandra Multiwavelength Plane Survey (ChaMPlane): Photometry Results from the First Two Years

P. Zhao, J. E. Grindlay, P. Edmonds, M. R. Garcia, J. E. McClintock (Harvard-Smithsonian CfA), H. Cohn, P. Lugger, S. Slavin (Indiana U.), D. W. Hoard, S. Wachter (CTIO)

We present the photometric results of the Chandra Multiwavelength Plane Survey (ChaMPlane), which is a project to identify a large sample of serendipitous X-ray sources in the galactic plane, in order to determine the populations of accretion-powered binaries in the Galaxy. Deep Chandra field observations have sufficient sensitivity to reach objects with Lx = 1031~erg/s out to about 7~kpc, i.e. a substantial fraction of the galactic disk. The ChaMPlane project has been chosen as one of the NOAO Long Term Survey Program. We have successfully conducted the ChaMPlane survey for the first two years and obtained deep images in the V, R, I and \bf H\alpha bands for more than 20 Chandra fields from the CTIO and KPNO 4-m telescopes, which covers more than eight square degrees in the galactic plane. Cataclysmic Variables (CVs) and quiescent Low Mass X-ray Binaries (qLMXBs) are identified by their ubiquitous \bf H\alpha excess as blue'' objects in the R vs. \bf (H\alpha - R) diagram. We describe our data analysis methods and present initial photometry results for this first significant sample of ChaMPlane optical data. Initial X-ray results for a subset of these fields are presented by Grindlay et al. This work is supported by NASA/SAO grant AR1-2001X and NSF grant AST-0098683.