Diffuse Extragalactic Background Light versus Deep Galaxy Counts in the Subaru Deep Field: Missing Light in the Universe?

Deep optical and near-infrared galaxy counts are utilized to estimate theextragalactic background light (EBL) coming from normal galactic light in theuniverse. Although the slope of number-magnitude relation of the faintestcounts is flat enough for the count integration to converge, considerablefraction of EBL from galaxies could still have been missed in deep galaxysurveys because of various selection effects including the cosmological dimmingof surface brightness of galaxies. Here we give an estimate of EBL from galaxycounts, in which these selection effects are quantitatively taken into accountfor the first time, based on reasonable models of galaxy evolution which areconsistent with all available data of galaxy counts, size, and redshiftdistributions. We show that the EBL from galaxies is best resolved intodiscrete galaxies in the near-infrared bands (J, K) by using the latest data ofthe Subaru Deep Field; more than 80-90% of EBL from galaxies has been resolvedin these bands. Our result indicates that the contribution by missing galaxiescannot account for the discrepancy between the count integration and recenttentative detections of diffuse EBL in the K-band (2.2 micron), and there maybe a very diffuse component of EBL which has left no imprints in known galaxypopulations.Comment: ApJ Letters in press. Two new reports on the diffuse EBL at 1.25 and 2.2 microns are added to the reference list and Table