A method to measure the mass of damped Ly alpha absorber host galaxies using fluctuations in 21-cm emission

Abstract

Observations of damped Lyα absorbers (DLAs) indicate that the fraction of hydrogen in its neutral form (H i) is significant by mass at all redshifts. This gas represents the reservoir of material that is available for star formation at late times. As a result, observational identification of the systems in which this neutral hydrogen resides is an important missing ingredient in models of galaxy formation. Precise identification of DLA host mass via traditional clustering studies is not practical owing to the small numbers of known systems being spread across sparsely distributed sightlines. However, following the completion of re-ionization, 21-cm surface brightness fluctuations will be dom..