The most significant unknown in searches for high-zstarburst galaxies is the role and importance of absorption by dust. Emission line searches have mostly targeted the Lyα line, which, due to resonant scattering, will be strongly suppressed even if only small amounts of dust are present. Indeed, most of the high redshift starburst galaxies identified by Steidel et al. (1996) havenoLyα emission. TheU-band andV-band dropout techniques developed by these authors and by Madau et al. (1996) are

more »

... ise sensitive to dust absorption, both because of absorption of the observed ultraviolet (UV) radiation and because UV-obscured galaxies will not be accounted for in these dropout studies.