A new algorithm for modelling photoionising radiation in smoothed particle hydrodynamics

TL;DR

This paper introduces a fast, accurate algorithm for simulating photoionising radiation in 3D smoothed particle hydrodynamics, enabling detailed star formation studies with complex density structures.

Contribution

The authors develop a novel algorithm combining a Strömgren volume technique with SPH to efficiently model ionising radiation in 3D star formation simulations, validated against Monte Carlo methods.

Findings

Good agreement with MOCASSIN in complex density fields

Effective in high-resolution 3D SPH simulations

Handles highly inhomogeneous density distributions

Abstract

We present a new fast algorithm which allows the simulation of ionising radiation emitted from point sources to be included in high-resolution three-dimensional smoothed particle hydrodynamics simulations of star cluster formation. We employ a Str\"omgren volume technique in which we use the densities of particles near the line-of-sight between the source and a given target particle to locate the ionisation front in the direction of the target. Along with one--dimensional tests, we present fully three--dimensional comparisons of our code with the three--dimensional Monte-Carlo radiative transfer code, MOCASSIN, and show that we achieve good agreement, even in the case of highly complex density fields.