Early Phases of Protostellar Discs – Studies with radiation transfer magneto-hydrodynamic simulations

All protostars are surrounded by a disc-like structure or proper Keplerian disc. Those discs are essential to understand the subsequent evolution of the protostar and are most probably the birthplaces of binary or multiple stellar systems, apart from being the nurseries of planets. Nevertheless, it is fairly unknown how the discs, and hence the protostars are decoupled from the infalling envelope and molecular clouds. Therefore we execute self-consistent simulations with radiation feedback of protostars and discs which are still embedded in an accreting envelope to track their late evolution. For this we employ our in-house developed hybrid characteristics radiation transfer scheme [Buntemeyer et al., 2016], which is build upon FLASH. Since the publication the solver has been extended to include the radiation of point sources as demonstrated in figure 4 (bottom), which are modeled by sink particles [Federrath et al., 2010] coupled to a star formation evolution model [Offner et al., 2009, Klassen et al., 2012]. Therefore these young stellar objects can irradiate the surrounding disk and envelope
The figure shows the result of a low resolution test simulation of a low mass molecular cloud collapse simulation. In this non-turbulent simulation a protostellar disc has already been formed. Since the central core has become optically thick, cooling by radiation is not effective any more. As a result the core heats up. If the central core contracts further the formation of a protostar is imminent.
Radiative transfer simulations