Title: Understanding the Dynamics of Protostellar Outflows with STARFORGE Simulations Tentative Poster title: Hydrodynamic benchmark simulations of stellar convection with MARBL
Abstract: Most stars form alongside gravitationally bound companions in turbulent molecular clouds, where the specific processes that set their orbital and rotational configurations are not well understood. A young star's angular momentum and the collimated outflows it launches along its rotation axis retain a record of its dynamical history and of the conditions under which it formed. Observations of outflows constrain this picture by measuring their orientations, but only as projected on the plane of the sky. 3D simulations can aid by providing access to the full geometry and the dynamical history of every star. I will present work using the STARFORGE simulations, which follow the formation of a star cluster from a turbulent molecular cloud with magnetic fields, radiative transfer, and protostellar outflows. Using a catalogue of outflow orientations extracted from these simulations together with the dynamical history of every star, I examine how outflow morphologies, stellar spins, and orbital angular momenta relate to one another, how those relationships depend on separation and multiplicity, and how much of the apparent alignment survives when the same measurement is made in projection. These results have implications for understanding the formation of multiple systems and for interpreting observed outflow orientations across systems of different multiplicity. Poster abstract: Convection in stellar interiors is a demanding computational problem: it couples a steep, buoyancy driven flow to a high energy density environment and must remain stable over many convective turnover times. We present the first simulations of stellar convection using MARBL, LLNL's high order finite element ALE code, whose fully compressible multi material formulation offers capabilities unavailable in the lower order codes conventionally used for stellar hydrodynamics. Using a 2D axisymmetric spherical shell, we reproduce a published hydrodynamic benchmark of solar convection and find stable steady state convection maintained over long integrations. These results are a first step toward using MARBL for configurations that are challenging for existing codes in stellar hydrodynamics, such as rapidly rotating, non spherical stars and their magnetic dynamos.