RX J1839.0+7257 , the SIMBAD biblio

We describe a program for the optical identification of a representative sample of RASS sources contained in six study areas north of δ=-9°, with |b^II|>20° including one region near the North Galactic pole (NGP) and one near the North Ecliptic pole (NEP) and present some preliminary results. A full identification has been carried out for a count-rate and area-limited complete subsample comprising 674 sources. The ratio of "extragalactic" ( e.g. AGN, clusters of galaxies) to "stellar" (e.g. coronal emitters, active binaries) counterparts was found to depend on the galactic neutral hydrogen column density, N_H. In the area near the NGP (low N_H) "extragalactic" counterparts dominate, while in the area with the highest N_H most X-ray sources are identified with stellar counterparts.