Simulation of radiation-driven winds from disc galaxies

Abstract

We present two-dimensional (2D) hydrodynamic simulation of rotating galactic winds driven by radiation. We study the structure and dynamics of the cool and/or warm component (T ≈104 K) which is mixed with dust. We have taken into account the total gravity of a galactic system that consists of a disc, a bulge and a dark matter halo.We find that the combined effect of gravity and radiation pressure from a realistic disc drives the gas away to a distance of ∼5 kpc in ∼37 Myr for typical galactic parameters. The outflow speed increases rapidly with the disc Eddington parameter Γ0(= κI/(2cGΣ)) for Γ0 ≥ 1.5. We find that the rotation speed of the outflowing gas is ≤100 km s−1. The wind is confined in a cone that mostly consists of low angular momentum gas lifted from the central region.