Feedback and Triggered Star Formation - From the Pillars of Creation to the Formation of the Solar System Matthias Gritschneder Univ. California, Santa Cruz, USA
We study the structural evolution of turbulent molecular clouds under the influence of ionizing radiation emitted from a nearby massive star by performing a high-resolution parameter study with the SPH code iVINE. In our simulations, the ionizing radiation enhances the initial turbulent density distribution and thus leads to the formation of pillar-like structures observed adjacent to HII regions in a natural way. To enable a close comparison with observations we post-process the simulations with the fully 3D radiative transfer code MOCASSIN. We find a close match with the observed quantities. Using the results of the MOCASSIN calculations we are able to derive a parameterized treatment of the diffuse field. We then present a new implementation of ionization in the SPH code SEREN, which is capable of treating multiple point-sources with a Monte Carlo approach. First results of this implementation on the efficiency of feedback will be discussed. Finally, we investigate the future evolution of the pillars as soon as the massive star explodes in a supernova. We are able to show that a surviving core at the border of the HII-region (D~5pc) is getting enriched sufficiently with supernova material and is triggered into collapse fast enough to be consistent with the tight constraints put by meteoritic data of e.g. Al26 on the formation of our Solar System. We therefore propose that the formation of the Solar System was triggered by the shock wave of a type IIa supernova interacting with surviving cold structures similar to the Pillars of Creation at the border of HII-regions.
Collaborators: D.N.C. Lin, UCSC, USA; B. Ercolano, USM, Germany; A. Burkert, USM, Germany; S. Walch, MPA, Germany; Q-Z. Yin, UCD, USA; S. D. Murray, LLNL, USA	Key publication