Simulation of radiation driven wind from disc galaxies

TL;DR

This paper uses 2-D hydrodynamic simulations to explore how radiation pressure from a galactic disc drives cool gas outflows, considering gravity and dust effects, revealing outflow speeds and structure.

Contribution

It presents a detailed simulation of radiation-driven galactic winds including gravity, dust, and rotation, highlighting the conditions for wind acceleration and structure.

Findings

Gas is driven up to 5 kpc in ~37 Myr under typical parameters.

Outflow speed increases rapidly with disc Eddington parameter for Γ₀ ≥ 1.5.

Wind is confined in a cone with low angular momentum gas.

Abstract

We present 2-D hydrodynamic simulation of rotating galactic winds driven by radiation. We study the structure and dynamics of the cool and/or warm component($T \simeq 10^4$ 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 $\sim 5$ kpc in $\sim 37$ Myr for typical galactic parameters. The outflow speed increases rapidly with the disc Eddington parameter $\Gamma_0(=\kappa I/(2 c G \Sigma)$) for $\Gamma_0 \ge 1.5$. We find that the rotation speed of the outflowing gas is $\lesssim 100$ km s$^{-1}$. The wind is confined in a cone which mostly consist of low angular momentum gas lifted from the central region.