April 29
Stars and atoms on supercomputers
Speaker: Dr. Mike Grudić, Flatiron Institute Center for Computational Astrophysics
Abstract: Star formation proceeds in our Galaxy in a way that is not so easily understood. Giant molecular clouds (GMCs) outweigh the most massive star clusters by orders of magnitude - star formation is inefficient. The mass spectrum of young stars - the IMF - exhibits a remarkable degree of regularity, across a wide range of conditions. Both facts suggest a certain degree of self-regulation, which can be understood within the same paradigm: the competition of stellar feedback versus gravity. GMCs resist analytic calculations, so high-resolution, multi-physics numerical hydrodynamics simulations have proven to be the decisive laboratory for studying the physics of star formation in recent years. Numerical GMC simulations have progressed over the past decade from very simplistic setups to a much more realistic, physically-complete model with all feedback processes acting in concert.
I will share some things we have learned from these simulations, and some striking predictions that the models make in exotic environments. I’ll also discuss some new puzzles we have opened up. Now that stellar feedback is accounted for, we must revisit previously-neglected microphysical processes in the ISM that may also prove decisive, i.e. it is time to shift our attention from stars back to atoms. I’ll end by describing some new approaches to constructing and numerically integrating microphysics networks that I think are promising.
Host: Prof. Massimo Ricotti