Numerical simulations of the rate of star formation in external galaxies

Abstract

Numerical simulations of the rate of star formation in external galaxies are discussed in terms of recent observations. Previously determined dependences of the star formation rate on some high power (7V~2) of the gas density are shown to depend critically on the correlation method generally employed. If the efficiency of converting gas into stars is low, the observed correlations of bright stars and H n regions with neutral hydrogen surface densities are shown to be reasonably consistent with star formation timescales which are proportional to p_1/2, where p is the initial local gas density. This form of the dependence on the gas density is taken as a direct indication that the dominant mechanism producing stars is regulated by gravitational