Sink particle radiative feedback in smoothed particle hydrodynamics models of star formation

Abstract

We present a new method for including radiative feedback from sink particles in smoothed particle hydrodynamics simulations of low-mass star formation, and investigate its effects on the formation of small stellar groups. We find that including radiative feedback from sink particles suppresses fragmentation even further than calculations that only include radiative transfer within the gas. This reduces the star formation rate following the formation of the initial protostars, leading to fewer objects being produced and a lower total stellar mass. The luminosities of sink particles vary due to changes in the accretion rate driven by the dynamics of the cluster gas, leading to different luminosities for protostars of similar mass. Including feedback from sinks also raises the median stellar mass. The median masses of the groups are higher than typically observed values. This may be due to the lack of dynamical interactions and ejections in small groups of protostars compared to those that occur in richer groups. We also find that the temperature distributions in our calculations are in qualitative agreement with recent observations of protostellar heating in Galactic star-forming regions.