Simulating a gravitational collapse to stellar densities
Abstract : Stars form as a result of the collapse of gravitationally unstable molecular cloud cores. This process, despite having occurred countless times in the Universe, remains poorly understood because of the challenges involved in observing star forming regions, as well the theoretical difficulties associated with modelling a highly non-linear process in which self-gravitating hydrodynamics, magnetic fields, radiative transfer, and turbulence, all play out simultaneously and exhibit a complex web of interactions. In this regard, numerical simulations have offered invaluable insights that have pioneered much of our understanding in the field. Most notably, these have revealed a two-step evolutionary sequence in which a first core in hydrostatic equilibrium forms, which itself collapses to form a protostar. This second gravitational collapse is a highly dynamical process, and as such, is a challenging undertaking from a numerical point of view. Nevertheless, the leaps and bounds in computing power achieved in recent decades have allowed us to model the birth of stars with unprecedented detail. During this seminar, I will present the results of my 3D calculations and the insights they have provided on the birth of stars, brown dwarfs, and circumstellar disks.