The evolution of a circumplanetary disc with a dead zone

Abstract

ABSTRACT We investigate whether the regular Galilean satellites could have formed in the dead zone of a circumplanetary disc. A dead zone is a region of weak turbulence in which the magnetorotational instability is suppressed, potentially an ideal environment for satellite formation. With the grid-based hydrodynamic code fargo3d, we examine the evolution of a circumplanetary disc model with a dead zone. Material accumulates in the dead zone of the disc leading to a higher total mass and but a similar temperature profile compared to a fully turbulent disc model. The tidal torque increases the rate of mass transport through the dead zone leading to a steady-state disc with a dead zone that does not undergo accretion outbursts. We explore a range of disc, dead zone, and mass inflow parameters and find that the maximum mass of the disc is around $0.001 M_{\rm J}$. Since the total solid mass of such a disc is much lower, we find that there is not sufficient material in the disc for in situ formation of the Galilean satellites and that external supplement is required.