2010ApJ...724.1389M

We present a map of the diffuse ultraviolet cosmic background in two wavelength bands (FUV: 1530 Å and NUV: 2310 Å) over almost 75% of the sky using archival data from the Galaxy Evolution Explorer (GALEX) mission. Most of the diffuse flux is due to dust-scattered starlight and follows a cosecant law with slopes of 545 photons/cm2/s/sr/Å and 433 photons/cm2/s/sr/Å in the FUV and NUV bands, respectively. There is a strong correlation with the 100 µm Infrared Astronomy Satellite (IRAS) flux with an average UV/IR ratio of 300 photons/cm2/s/sr/Å (MJy/sr)^–1 in the FUV band and that of 220 photons/cm2/s/sr/Å (MJy/sr)^–1 in the NUV band but with significant variations over the sky. In addition to the large-scale distribution of the diffuse light, we note a number of individual features including bright spots around the hot stars Spica and Achernar.