Abstract

Contributed Talk - Splinter StarFormation

The High-resolution Accretion Disks of Embedded protoStars (HADES) simulations: How the protostellar magnetic field impacts accretion

Brandt Gaches
University of Duisburg-Essen

The physical mechanisms underlying accretion onto actively accreting, embedded protostars are still debated. There has been a substantial gap in high-resolution numerical simulations to cover this embedded phase when most of the protostar's mass is accreting. Observations can now provide key constraints for embedded protostars, especially from the VLTI GRAVITY instrument. I will present the results from the High-resolution Accretion Disks of Embedded protoStars (HADES) simulations, with a focus on the role of the protostellar magnetic field on gas accretion and ejection. The simulations demonstrate a relatively clear story on the impact of the protostellar magnetic field strength. For weakly or unmagnetized protostars, accretion occurs via turbulent boundary layer accretion, with gas freely falling across the surface. For marginally magnetized protostars, the accretion is still via boundary layer, but the presence of a bipolar outflow compresses the disk flow, constraining the accretion and reducing the variability. Finally, for highly magnetized protostars, the accretion mechanism splits into two different options depending on the locations of the truncation and corotation radii, resulting either in turbulent magnetospheric or an instability-driven accretion. I will conclude by showing initial results on outflow launching and prospects for future simulations, along with how these simulations help couple our knowledge of star formation from the small to large scales.