IDENTIFICATION OF SELECTED SOURCES FROM THE ROSAT GALACTIC PLANE SURVEY - I

We report oil optical searches in the error circles of 93 ROSAT survey sources located at low galactic latitudes (\b\ < 200). These sources were extracted from the ROSAT Galactic Plane Survey using various sele ction criteria on hardness ratio: X-ray and optical brightness and int egrated galactic absorption in the direction of the source. We find op tical identifications in 76 cases, among which are 25 new AGN 6 new CV s and a new Be/X-ray binary. In order to illustrate the relevance of t he source selections applied here, we cross-correlated the ROSAT all-s ky survey bright source list with SIMBAD. Different classes of X-ray e mitters populate distinct regions of a multi dimensional parameter spa ce involving flux ratios, galactic latitude and N-H. This relatively g ood segregation offers the possibility to build source samples with en hanced probability of identification with a given class. Complete opti cal identification of such subsamples could eventually be used to comp ute meaningful probabilities of identification for all sources using a s basis a restricted set of multi-wavelength information.