Computing Models for Faint-Galaxy Samples

Abstract

Given evolutionary models for galaxies with various histories of star formation, it remains to compute the number of each type as a function of apparent magnitude. This computation automatically yields the number as a function of redshift and the number as a function of apparent color, both also observable distribution functions. (One can think of other observables, of course: the distribution of surface brightness, image compactness parameters, rotation curve amplitudes and shapes, etc.) The goal is to compare the computation directly with the observed properties of magnitude-limited samples of field galaxies to see how good the match is, and what parameters the model is most sensitive to.