Impact of radiation feedback on the assembly of star clusters in galactic context

TL;DR

This study uses high-resolution hydrodynamical simulations to examine how radiation feedback influences star cluster formation and evolution in a low-mass galaxy, highlighting its dominant role over supernovae in disrupting dense gas and affecting cluster growth.

Contribution

It provides new insights into the non-linear effects of radiation feedback on star cluster assembly and the conditions that lead to different cluster outcomes in a galactic environment.

Findings

Radiation feedback is more effective than supernovae in destroying dense gas.

Feedback influences cluster mass growth by increasing gas energy and overcoming gravity.

Two categories of star clusters are identified based on gas expulsion success.

Abstract

Massive star clusters are observed in a broad range of galaxy luminosity and types, and are assumed to form in dense gas-rich environments. Using a parsec-resolution hydrodynamical simulation of an isolated gas-rich low mass galaxy, we discuss here the non-linear effects of stellar feedback on the properties of star clusters with a focus on the progenitors of nuclear clusters. Our simulation shows two categories of star clusters: those for which feedback expels gas leftovers associated with their formation sites, and those, in a denser environment around which feedback fails at totally clearing the gas. We confirm that radiation feedback (photo-ionization and radiative pressure) plays a more important role than type-II supernovae in destroying dense gas structures, and altering or quenching the subsequent cluster formation. It also disturbs the cluster mass growth, by increasing the internal energy of the gas component to the point when radiation pressure overcomes the cluster gravity. We discuss how these effects may depend on the local properties of the interstellar medium, and also on the details of the subgrid recipes, which can affect the available cluster gas reservoirs, the evolution of potential nuclear clusters progenitors, and the overall galaxy morphology.