Comparisons of a standard galaxy model with stellar observations in five fields

Abstract

Modern data on the distribution of stellar colors and on the number of stars as a function of apparent magnitude in five directions in the Galaxy are analyzed. It is found that the standard model is consistent with all the available data. Detailed comparisons with the data for five separate fields are presented. The bright end of the spheroid luminosity function and the blue tip of the spheroid horizontal branch are analyzed. The allowed range of the disk scale heights and of fluctuations in the volume density is determined, and a lower limit is set on the disk scale length. Calculations based on the thick disk model of Gilmore and Reid (1983) are presented.