The Origin of Jovian Planets in Protostellar Disks: The Role of Dead Zones

The final masses of Jovian planets are attained when the tidal torques that they exert on their surrounding protostellar disks are sufficient to open gaps in the face of disk viscosity, thereby shutting off any further accretion. In sufficiently well ionized disks, the predominant form of disk viscosity originates from the magnetorotational instability (MRI) that drives hydromagnetic disk turbulence. In the region of sufficiently low ionization …