A study of the Ha i gas fractions of galaxies at z ∼1

Abstract

Aims. Due to the fact that Ha I mass measurements are not available for large galaxy samples at high redshifts, we apply a photometric estimator of the Ha I-to-stellar mass ratio (M/M∗), calibrated using a local Universe sample of galaxies, to a sample of galaxies at za ∼a 1 in the DEEP2 survey. We use these Ha I mass estimates to calculate Ha I mass functions (HIMFs) and cosmic Ha I mass densities (ω) as well as to examine the correlation between star formation rates and Ha I gas content for galaxies at za ∼a 1. Methods. We have estimated Ha I gas masses for ∼7000 galaxies in the DEEP2 survey with redshifts in the range 0.75a