Possible forest of emission lines from protogalaxies

Abstract

We discuss the possibility of detecting protogalaxies in the ultraviolet, assuming that galaxy formation occurred at z ~ 5-6. We show that the diffuse gas in collapsing galaxy-sized objects with temperatures ~10^6+0.5 K, and with modest metallicities, should produce many emission lines from highly ionized iron atoms. We compare the expected luminosity from models of galaxy formation with the sensitivity of the Hubble Space Telescope (HST).