Session B14 - Galaxies, Supernovae, and Cosmology.
ORAL session, Saturday morning, April 28
Room 14, Renaissance Hotel$
We report the results of a search for "Lyman break" galaxies in fields containing z=4 Damped Lyman alpha absorbers (DLAs) along the line of sight to distant quasars. We searched for emission from galaxies physically associated with the DLAs, which are dense clouds of neutral hydrogen believed to be the building blocks of normal galaxies. We have conducted a survey to find all z>3.5 galaxies in the field in order to explore the clustering environment of the DLAs. In essence we have applied large-scale structure techniques to the study of galaxy formation by exploring the cross-correlation between bright star-forming (Lyman break) galaxies and dense clouds of neutral gas (DLAs) in the early universe. Our initial results (Gawiser et al 2001) find an overdensity of galaxies near a DLA at z=3.86, implying that DLAs are highly biased and hence quite massive. If the cross-correlation is equally strong in other DLAs, this would represent a serious challenge to the prevailing hierarchical models of cosmological structure formation.