ESTIMATES FOR THE LUMINOSITY FUNCTION OF GALAXIES AND ITS EVOLUTION

A new method is presented to obtain a non-parametric maximum Likelihoo d estimate of the luminosity function and the selection function of a flux-limited redshift survey. The method parametrizes the selection fu nction as a series of stepwise power laws and allows possible evolutio n of the luminosity function. We also propose a new technique to estim ate the rate of evolution of the luminosity function. This is based on a minimization of the observed large-scale power with respect to the evolutionary model. We use an ensemble of mock surveys extracted from an N-body simulation to verify the power of this method. We apply our estimators to the 1.2-Jy survey of IRAS galaxies. We find a far-infrar ed luminosity function in good agreement with previously published res ults and evidence for rather strong evolution. If the comoving number density of IRAS galaxies is assumed to scale proportional to(1 + z)(P) , we estimate P = 4.3 +/- 1.4.