FAR-ULTRAVIOLET DIFFUSE BACKGROUND AND GALAXY COUNTS

We have used galaxy counts obtained at 2000 angstrom down to a magnitu de of 18.5 to calculate the ultraviolet integrated light of galaxies. The calculation is based on models developed to interpret the galaxy c ounts. Because of various sources of uncertainty, the extrapolated val ues lie in the range 40 - 130 photons cm-2 s-1 angstrom-1 sr-1. This e xtrapolated intensity is comparable to the extragalactic ultraviolet b ackground estimated from direct background measurements, demonstrating that the integrated light of galaxies must be a significant contribut or to the extragalactic ultraviolet background.