Modeling the Near-Infrared Luminosity Functions of Young Stellar Clusters

We present the results of numerical experiments designed to evaluate the usefulness of near-infrared luminosity functions for constraining the Initial Mass Function (IMF) of young stellar populations. We test the sensitivity of the near-infrared K band luminosity function (KLF) of a young stellar cluster to variations in the underlying IMF, star forming history, and pre-main sequence mass-to-luminosity relations. Using Monte Carlo techniques, we create a suite of model luminosity functions systematically varying each of these basic underlying relations. From this numerical modeling, we find that the luminosity function of a young stellar population is considerably more sensitive to variations in the underlying initial mass function than to either variations in the star forming history or assumed pre-main-sequence (PMS) mass-to-luminosity relation. Variations in a cluster’s star forming history are also found to produce significant changes in the Smithsonian Predoctoral Fellow present address: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Mail Stop 42, Cambridge, MA 02138 USA