Star Formation as a Cosmological Probe

Abstract

We discuss the cosmological dependence of the star formation history of the universe, within the framework of a very simple semianalytic model, where star formation occurs within the virialized cores of dark matter halos, at a rate which is primarily governed by the rate of matter infall into the halo core. Our model is extremely simple, contains a number of uncertain features, and cannot be expected to predict detailed properties of the galaxy distribution. In spite of these great uncertainties, we find that at sufficiently high redshifts fundamental differences between cosmologies (and not uncertainties in the star formation model) are the dominant factor determining star formation history. Consequently, we argue that observations of star-forming galaxies at high redshift (z > 5) with telescopes such as the Next Generation Space Telescope (NGST) can provide a powerful probe of cosmology.