An all-sky Atlas of Radio/X-ray Associations
  An all-sky comprehensive catalog of calculated radio and X-ray associations
to optical objects is presented. Included are X-ray sources from XMM-Newton,
Chandra and ROSAT catalogs, radio sources from NVSS, FIRST and SUMSS catalogs,
and optical data, identifications and redshifts from the APM, USNO-A, SDSS-DR7
and the extant literature. This "Atlas of Radio/X-ray Associations" inherits
many techniques from the predecessor Quasars.org (2004) catalog, but object
selection is changed and processing tweaked. Optical objects presented are
those which are calculated with >=40% confidence to be associated with
radio/X-ray detections, totalling 602570 objects in all, including 23681 double
radio lobe detections. For each of these optical objects I display the
calculated percentage probabilities of its being a QSO, galaxy, star, or
erroneous radio/X-ray association, plus any identification from the literature.
The catalogue includes 105568 uninvestigated objects listed as 40% to >99%
likely to be a QSO. The catalog is available at http://quasars.org/arxa.htm .
