Radiative Feedback and the Formation of Massive Stars and Stellar Clusters

8.2.2016
Ralph Pudritz

ABSTRACT:
Radiative feedback is a key process in astrophysics that plays a crucial role in the formation of massive stars
and the star clusters in which they form. I will review the physical problems and large body of work that has addressed these basic questions before turning to our own contributions. For massive star formation, we have developed a new hybrid radiative transfer code that operates in a full 3D, adaptive mesh environment that can, for the first time, follow the heating and momentum transfer by both discrete stellar sources as well as by diffuse radiative background in complex geometries. We simulate the gravitational collapse of massive dense gaseous "cores" of 30 to 200 solar masses. Two important differences with
earlier simulations are that radiative forces are able to drive material away without cooling and the "fallback" to the forming
accretion disks, and that these massive disks do not undergo rapid fragmentation into multiple stars.
I will also present our new work on radiative feedback simulations of the formation of young clusters
in turbulent Giant Molecular Clouds and on how cloud structure affects this process. In particular, we find that
the star formation efficiency in such clouds and the masses of star clusters are strongly influenced by how gravitationally bound
the cloud are initially - an effect that is at least as important as that of radiative feedback.