SF-08-0010

Investigating the multiplicity of stellar systems in the field using Monte Carlo simulations

Rebecca Jane Houghton

Recent large-scale surveys of field stars and local star-forming regions have made increasingly accurate measurements of stellar multiplicity, providing new insights into how multiplicity fractions vary with environment and primary mass. They show that even though most stars form in multiple systems, the multiplicity of field stars is much lower than than for local star-forming regions. Decades of observations have also shown a strong dependence on multiplicity on primary mass. These two factors might indicate that there is a high destruction/decay rate of stellar systems post formation, and/or the multiplicity of the system depends on the initial mass of the star forming core. However, the process of multiple system formation is still not well understood, and we need theoretical models to accompany these observations to understand stellar multiplicity. In this poster, I will present the results of Monte Carlo simulations that use a statistical approach to model the formation of bound stellar systems from molecular cores. These simulations test how the initial core mass affects the multiplicity of a system, and how the dynamical evolution of these systems (due to dynamical disruption and decay due to gravitational instabilities) might modify the multiplicities from local star forming regions to generate the field population. I have tested several different models, with a variety of conditions for both core fragmentation and decay, and presented the results of some characteristic models in this work. The simulation data is used to generate multiplicity fractions as a function of primary mass and a synthetic initial mass function (IMF), which are compared to observations. This poster also discusses the implications that these models have on the universality of star formation.