This is a quick viewer of the XMM-Newton Serendipitous Source Catalog and the Chandra X-ray Source Catalog.

  Each row includes RA, Dec, search radius in arcsec and output option. The search radius is optional and is 6 arcsec by default, but is needed when the output option is used. The output option is optional and is 0 by default, meaning that only the closest match within the search radius for each entry is shown; otherwise it should be specified to be 1 to show all matches within the search radius.