Radiative feedback in star formation: a novel method for linking SPH and radiation transport

Stars are formed by the gravitational collapse of enormous clouds of cold dust and gas. As the initial cloud collapses it fragments into smaller sub-clouds, which may in turn also fragment.It is this fragmentation process that is thought to lead to the different stellar masses we see in clusters of stars, with many more low-mass stars being formed compared to high-mass stars.We are now capable of performing supercomputer simulations that follow the collapse from the initial cloud right through to the stars, but these calculations do not include so-called radiation transfer, which simulates that passage of light through the gas and its subsequent heating effects. In essense the protostars that are formed in the current simulations do not shine.We wish to incorporate radiation transfer into the collapse simulations by merging two state-of-the-art computer codes, one of which simulates the motion of the gas, and the other the paths of photons through the gas. This will allow us to effectively turn on the stars as they form, allowing them to heat up the cloud. We think that this more sophisticated treatment of the problem will provide new insight into the collapse and fragmentation process, and enable us to better predict the distributions of stellar masses that we see in the Universe.