Abstract

Contributed Talk - Splinter PlanetFormation

Thursday, 18 September 2025, 15:15

Hypersonic accretion in wind-emitting transitional discs

Sarafidou, E.; Gressel, O.; Ercolano, B.
AIP+UP, AIP, LMU

Transition discs are a type of protoplanetary disc characterised by a central dust and gas cavity. The processes behind how these cavities are formed and maintained, along with their observed high accretion rates, continue to be subjects of active research. Aims. This work aims to investigate how the inclusion of the Hall effect (HE) alongside Ohmic resistivity (OR) and ambipolar diffusion (AD) affects the overall structure. Of key interest is the dynamical evolution of the cavity and whether it can indeed produce transonic accretion, as hypothesised in order to account for the observed high accretion rates despite the inner disc's low gas density. Our models maintain an intact inner cavity and an outer standard disc; MHD winds are indeed launched from both regions. Notably, when the HE is included, ring-like structures develop within the cavity. We moreover obtain accretion rates comparable to typical values seen in full disks. Importantly, we clearly observe transonic accretion in the cavity. Additionally, outward magnetic flux transport is typically seen.