GALEX UV Unique Source Catalogs ("GUVcat") and Cross-Matches With Gaia and SDSS ("GUVmatch")

The GALEX database contains almost 600 million source measurements in far-UV and near-UV. Some sources have repeated measurements (useful to search for variability, for example), due to repeated observations of the same field or overlap between fields. Bianchi, Shiao, and Thilker 2017 constructed catalogs of clean, unique (i.e. only one entry for each object) UV sources, useful to estimate density of sources across the sky or the number of sources with given magnitude or color ranges, or to match UV sources with other catalogs (revised version 2020). Flags are included to check for artifacts, as well as for existing multiple observations, and flags indicating whether a source is within the footprint of a large galaxy or stellar cluster (see Figure 5 in Bianchi et al. 2017) where source identification and photometry may be unreliable or inconsistent across the bands. GUVcat is composed using tiles from the AIS (All-Sky Imaging Survey), with a depth of about 19.9/20.8 in FUV/NUV ABmag. Bianchi & Shiao 2020 matched the GUVcat_AIS with SDSS DR14 and Gaia DR2 databases (GUVmatch). Tags are included to identify and track multiple optical matches to UV sources. For details about the matching parameters, and catalogs content in terms of astrophysical classes of objects, see Bianchi & Shiao 2020.