Objects with Sources
The Status column returned by the service titled "Search Objects and Unprocessed Catalog Sources" indicates the NED processing status. A Status of S (catalog source) indicates an astronomical observation which has not yet been fully integrated into NED's representation of the hierarchy of the universe. A Status of O (NED object) indicates a physical thing or a group of things in the universe, or a region of space. This can result from a catalog entry being cross-identified or associated by NED with other observations in the database, or from a vetted catalog entry that does not match other entries in the database, thus indicating a previously unknown object.
A source of radiation represented by a catalog source entry (row) may contain emission originating from (1) a single astrophysical object (e.g., a galaxy or a star), (2) multiple astrophysical objects (e.g., a pair of galaxies), (3) a region inside a larger physical object (e.g., a star cluster within a galaxy), or (4) an instrumental artifact. Also, the universe is hierarchical, so compound objects (e.g., galaxy groups) contain other objects (galaxies), and objects within those objects (e.g., star clusters, stars), etc. NED attempts to keep this all sorted out as new data are published.
Depending on the outcome of an ongoing process involving cross-matching of catalog source parameters (positions, fluxes, diameters, beam size, etc.) with other data in NED, an S entry may later be flagged either as O, meaning it was cross-identified with a previously known NED object, or it had no match and thus became a new NED object (with or without associations to other NED objects). If you do not want to see the unprocessed catalog sources (S) that NED knows about which have not yet been cross-matched (or may be artifacts, etc.), the user interface can be used to query only fully integrated NED objects (O).