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.
281.85485 -63.29027 6 0
281.85485, -63.29027 90
18:47:25.164 , -63:17:24.972
18 47 25.164 -63 17 24.972