A computer model universe - Simulation of the nature of the galaxy distribution in the Lick catalog

Abstract

The development of a nondynamical computer model universe designed to match the character of the galaxy distribution in the Lick survey is described. The model assigns 'galaxy' positions in a three-dimensional clustering hierarchy, fixes absolute magnitudes, and projects angular positions of objects brighter than m = 18.9 onto the sky of an imaginary observer. This yields a galaxy map that can be compared to that of the Lick data. In the model there are 7.5 million galaxies at a mean space density of 0.065 h-cubed per Mpc (H = 100 h km/s per Mpc), and 386,000 galaxies are visible at apparent magnitudes of no more than 18.9 and galactic latitudes of at least 40 deg. By adjusting parameters in the model within the limits allowed by the correlation functions to fourth order, a galaxy map with a visual appearance that seems a reasonable first approximation to that of the Lick data is obtained.