We review primeval galaxy searches based on the Lyα line emission. Simple arguments are given which suggest that primeval galaxies (interpreted here as ellipticals and bulges undergoing their first major bursts of star formation) should be detectable with present-day technology. Many active objects are now known at large redshifts, which may be plausibly interpreted as young galaxies, but there is so far no convincing detection of a field population of forming normal galaxies. This suggests that either primeval galaxies were obscured, and/or are to be found at higher redshifts, zgf
Galaxy formation is one of the central problems of modern cosmology. It touches on many different subfields of astrophysics: formation and evolution of large-scale structure, chemical evolution and star formation history of galaxies and stellar populations, physics of star formation, etc. Discovery of normal galaxies forming at large redshifts will be an important milestone and would open many new exciting problems and fields of inquiry.
The purpose of this review is to describe some of the observational issues involved, to describe the results from modern searches for primeval galaxies (hereafter PGs), and the future prospects. Previous reviews include those by Davis 1980, Koo 1986, Spinrad 1987, 1989, Cowie 1988, 1989, Djorgovski 1988a,b, 1992, and numerous excellent papers in the proceedings edited by Frenk et al. 1989 and Bergeron et al. 1988; and also in Hewitt et al. 1987, Thuan et al. 1988, Kron & Renzini 1988, Kron 1990, and many others.