A Framework for Modeling Evolution of the Core Mass Function

Abstract

Our current picture of the observable Universe is supported by knowledge of the behavior and evolution of stars. However, the earliest stages of the lives of stars are a subject of considerable uncertainty, with central questions such as where the observed distribution of stellar masses originates or how stars gain their mass remaining unanswered. It is difficult to comprehensively evaluate or compare the many theories developed to explain the star formation process, given the limited amount of observational data and current modeling capacity. In this work, I present a collection of models and modeling tools developed to make a direct connection between theory and observation, opening the way to a comprehensive assessment of our picture of star formation.

I make significant updates to a set of young stellar object (YSO) models with spectral energy distributions (SEDs) calculated through radiative transfer. Such sets are commonly used to measure properties of YSOs; my additions expand the amount of measurable information. Moreover, I use this set to probe the validity of assumptions commonly made in observations of stellar precursors, including the temperature of circumstellar dust and the relationship between a YSO's appearance and its actual evolutionary state.

I develop an innovative method for modeling the evolution of YSOs which associates the radiative transfer models of my set with protostellar evolutionary tracks. This method connects the theoretical parameters of star formation directly to observables and allows the many existing theories for protostellar accretion to be considered on even footing. I show that YSOs following multiple accretion models exhibit distinct behavior that may be identified through far-IR and millimeter photometric observations. Further, I assess the impact of model construction on radiative transfer simulations and extend analysis of observational YSO evolutionary indicators done with the base models.

Finally, I use this YSO modeling procedure as the heart of a framework for modeling populations of forming stars. I compare the distributions of several physical and observational properties for the members of populations with varying prescriptions for stellar mass assembly and formation history, finding that different theories have distinct and measurable effects on population-level observables.