The growth of disk galaxies disentangling evolution and selection biases

Abstract

We review the status of current observations of the fundamental parameters of intermediate redshift (0.2 < z < 1.2) spiral galaxies. Advances in instrumentation of 8–10m class telescopes have made possible detailed measurements of galaxy luminosity, morphology, kinematics and mass, in both the optical and the infrared passbands. By studying such well known star formation indicators as [OII]3727Å (in the optical) and Hα (redshifted to the infrared), the internal velocity structure and star formation rates of galaxies can be traced through this entire redshift regime. The combination of throughput and optimum seeing conditions yields spectra which can be combined with high resolution multiband imaging to explore the evolution of galaxies of various morphologies, and to place constraints on current models of galaxy formation and star formation histories. Out to redshifts of z = 1, these data form a high redshift Tully-Fisher relation that spans four magnitudes and extends to well below L∗, with no obvious change in shape or slope with respect to the local relation. A comparison of disk surface brightness between local and high redshift samples yields an offset in accordance with distance-dependent surface brightness selection effects, as can the apparent change in disk size with redshift for disks of a given mass. These results support low Ω0 models of formation, and provide further evidence for modest increases in luminosity with lookback time for the bulk of the field spiral galaxy population, given the limits imposed by the parent HST+WFPC2 imaging catalog.