Protoplanetary discs (PPDs) have been widely observed around young stars and are the birth cradle of planets. They are cold, dense and magnetised objects among which stand the transition discs (TDs) characterised by a dust cavity in the inner regions that extends from a few AU to a few hundreds AU and whose formation remains yet unexplained. Not only are such cavities seen in the dust profiles, but they are also detected in the gas profiles.
A striking observation that challenges intuition states that despite their diminished surface density profile, some TDs accrete at a rate similar to the accretion rates of full PPDs, suggesting a fast inward motion of matter in their cavity. A possible explanation for these high accretion rates is the presence of magnetised winds that would allow matter to fall onto the star at high radial velocity (Combet & Ferreira 2008, Wang & Goodman 2017).
The aim of the work presented in this poster is to tackle this observational discrepancy using magnetohydrodynamic (MHD) winds to account for accretion in TDs with the help of global numerical simulations.
I show the impact of the depleted gas repartition on the ionisation fraction as well as the results of 2.5D and 3D global simulations modelling TDs with magnetic winds in the non-ideal MHD framework. I will in particular focus on mass accretion through the cavity and on the 3D stability of this cavity against hydro and magneto-hydrodynamic instabilities.