RADIO-LOUD ACTIVE GALAXIES IN THE NORTHERN ROSAT ALL-SKY SURVEY .2. MULTIFREQUENCY PROPERTIES OF UNIDENTIFIED SOURCES

We present the broad band, radio - to - X-ray, properties of a large s ample of mostly previously optically unidentified radio-loud X-ray sou rces from the correlation of a ROSAT All-Sky Survey source list with t he 5 GHz Green Bank Survey of the northern sky (RGB sample) which is o ne of the largest well-defined flux-limited surveys of AGN ever obtain ed. Further, the RGB pushes 1-2 orders of magnitude deeper in both X-r ay 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 t hree 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. Although the nature of the sources as well as their redshifts remain to be determined in spectroscopic follow up observations, the derived flux ratios lead to the conclusion that the majority of them are quasars. Hardly any correlations could be found b etween different source parameters, possibly due to the fact that most of the objects are found in a relatively small flux range near the se nsitivity limit of the radio catalogue. The majority of the new RGB so urces have broad-band properties between those of traditional radio-se lected and Xray selected AGN. There is no bimodal distribution in the radio-loudness distribution, and the traditional division between radi o-quiet and radio-loud AGN may not be warranted.