Object catalogs are more typically searched to find matching objects, to classify sources, or similar tasks. A few object catalogs are associated with archival data. New catalogs are constantly being added. Users can search tables in several different ways. Users may simply request an image by specifying a position, or can make very detailed request for the size, scale, orientation, projection and coordinate system for the data.
Most surveys cover the entire sky.
Basically any resource that is queryably by position is eligible for entry into Astrobrowse. Currently over 1,000 resources are available. Many of the utilities described above are extremely useful in preparing proposals. Some capabilities of this system, particularly the ability to select and manipulate samples extracted from various catalogs, and to view and analyze selected data directly using xspec, ximage, and xronos, are not yet available in W3Browse but are planned for implementation. Typically only users familiar with the detailed structure of the archive will find this convenient since most FTP clients, especially for UNIX, are rather clumsy.