UV Radiation Fields Produced by Young Embedded Star Clusters

A large fraction of stars form within young embedded clusters, and these environments produce a substantial ultraviolet (UV) background radiation field, which can provide feedback on the star formation process. To assess the possible effects of young stellar clusters on the formation of their constituent stars and planets, this paper constructs the expected radiation fields produced by these clusters. We include both the observed distribution of cluster sizes $N$ in the solar neighborhood and an extended distribution that includes clusters with larger $N$. The paper presents distributions of the FUV and EUV luminosities for clusters with given stellar membership $N$, distributions of FUV and EUV luminosity convolved over the expected distribution of cluster sizes $N$, and the corresponding distributions of FUV and EUV fluxes. These flux distributions are calculated both with and without the effects of extinction. Finally, we consider the effects of variations in the stellar initial mass function on these radiation fields. Taken together, these results specify the distributions of radiation environments that forming solar systems are expected to experience.
Comment: Accepted for publication in ApJ