Modeling Spiral Galaxy Surface Luminosity to Explain Non-Uniform Inclination Distributions

The distribution of spiral and bar galaxy inclination an-gles is expected to be uniform. However, analysis of sev-eral major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and ISM density distributions. The luminous component is inte-grated along a particular line of sight, thus producing a mass distribution, from which a surface luminosity pro-file is derived. The ISM component is integrated along-side the luminous component to account for light extinc-tion. Preliminary data ignoring extinction demonstrate trends matching the observed small inclination distribu-tion. We reproduce overall spiral galaxy morphology and outline the ongoing validation process. Motivatio