Wednesday 15 Jun 2016: Radiative Feedback and the Formation of Massive Stars and Stellar Clusters
Prof. Ralph Pudritz - McMaster University
Physics, 4th Floor 14:30-15:30
Radiative feedback is thought to play 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 3D, adaptive mesh code (FLASH) 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. We find several major differences with respect to previous works including radiatively driven bubbles that don't
cool and fragment, as well as a suppression of fragmentation of the massive disks into multiple stars. Our results compare
favourably to recent observations of massive disks around massive 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 more important than radiative feedback. These results are compared with observations.