The Initial Mass Functions of Four Embedded Stellar Clusters

We present near-infrared $J$, $H$, and $K$ images of four embedded stellar clusters in the Galaxy. We find a significant fraction of pre-main-sequence stars present in at least one of the clusters. For the clusters dominated by main-sequence stars, we determine the initial mass function (IMF) both by using the $K$ luminosity function and a global extinction correction and by deriving individual extinction corrections for each star based on their placement in the $K$ vs. $H-K$ color-magnitude diagram. Based on our IMFs we find a significant discrepancy between the mean IMF derived via the different methods, suggesting that taking individual extinctions into account is necessary to correctly derive the IMF for an embedded cluster.