ROSAT detected quasars. II.

We present the broad band, radio - to - X-ray, properties of a large sample of mostly previously optically unidentified radio-loud X-ray sources from the correlation of a ROSAT All-Sky Survey source list with the 5GHz Green Bank Survey of the northern sky (RGB sample) which is one of the largest well-defined flux-limited surveys of AGN ever obtained. Further, the RGB pushes 1-2 orders of magnitude deeper in both X-ray and radio flux compared to previous unbiased wide-area AGN surveys.

Follow up VLA observations of the candidate objects yielded positions with arcsec accuracy which were used to find optical counterparts to the sources from digitized POSS plates. The sources are divided into three classes according to the positional offset between the X-ray and radio candidates and the spatial resolution of the radio observations, reflecting the various degrees of confidence about the correctness of the proposed association.