case western reserve university



Optical Extragalactic Background Light

Rebecca Bernstein (University of Michigan)

The integrated optical surface brightness of the Universe --- the optical extragalactic background light --- is dominated by starlight from galaxies (resolved and unresolved) to redshifts z<8. As such, it is a fundamental constraint on the star formation history of the Universe. In this talk, I will discuss the our recent results on the mean flux of the optical EBL at 3000, 5500, and 8000A and describe the coordinated HST/ground--based observing program from which these results were obtained. The EBL flux we detect is significantly larger than the integrated flux of resolved galaxies using standard photometric methods. Part of this difference is due to the difficulty of recovering flux in the low surface brightness wings of well-detected galaxies. I will discuss the implications of these results in the context of infrared EBL measurements, galaxy luminosity functions, and number counts and constraints on the star formation history, metal enrichment, and stellar baryon fraction in the Universe.