The effective temperature distribution of steady-state, mass-losing accretion discs

Abstract

Mass loss appears to be a common phenomenon among disk-accreting astrophysical systems. An outflow emanating from an accretion disk can act as a sink for mass, angular momentum and energy and can therefore alter the dissipation rates and effective temperatures across the disk. Here, the radial distributions of dissipation rate and effective temperature across a Keplerian, steady-state, mass-losing accretion disk are derived, using a simple, parametric approach that is sufficiently general to be applicable to many types of dynamical disk wind models. Effective temperature distributions for mass-losing accretion disks in cataclysmic variables are shown explicitly, with parameters chosen to describe both radiation-driven and centrifugally-driven outflows. For realistic wind mass-loss rates of a few percent, only centrifugally-driven outflows -- particularly those in which mass loss is concentrated in the inner disk -- are likely to alter the disk's effective temperature distribution significantly. Accretion disks that drive such outflows could produce spectra and eclipse light curves that are noticeably different from those produced by standard, conservative disks.