The impact of accretion heating and thermal conduction on the dead zone of protoplanetary disks

TL;DR

This study models how accretion heating and turbulent heat conduction influence the thermal structure and dead zone boundaries in protoplanetary disks, revealing significant effects on dust sublimation and disk cavity formation.

Contribution

It extends existing disk models by incorporating accretion heating and turbulent conduction, showing their impact on dead zone location and dust sublimation processes.

Findings

High accretion rates create a dust sublimation zone with a gaseous cavity.

Turbulent heat conduction significantly affects the disk's temperature profile.

Dead zone edges shift outward with increased accretion rates.

Abstract

The paper investigates the influence of accretion heating and turbulent heat conduction on the equilibrium of protoplanetary disks, extending the 2D axis-symmetric passive disk model of Flock (Flock et al. 2016, ApJ 827, 144). The model includes dust sublimation and radiative transfer with the flux-limited diffusion approximation, and predicts the density and temperature profiles as well as the dust to gas ratio of the disk. It is shown that the accretion heating can have a large impact: For accretion rates above 5*10^(-8) M_solar /yr a zone forms behind the silicate condensation front with sufficiently high temperature to sublimate the dust and form a gaseous cavity. Assuming a Prandtl number ~ 0.7, it is furthermore shown that the turbulent heat conduction cannot be neglected in the evaluation of the temperature profile. While the inner rim position is not affected by viscous heating, the dead zone edge shifts radially outward for higher accretion rates.