Survival of Star-Forming Giant Clumps in High-Redshift Galaxies

TL;DR

This paper examines how stellar radiation pressure influences the survival of massive star-forming clumps in high-redshift galaxies, finding that typical star formation rates allow these clumps to survive feedback effects during galaxy formation.

Contribution

It demonstrates that star-forming giant clumps in high-redshift galaxies are resilient to stellar feedback if they form stars at rates consistent with local observations and the Kennicutt-Schmidt law.

Findings

Clumps typically of 10^8-10^9 solar masses survive feedback.

Star formation rates in clumps are generally insufficient to cause disruption.

Rapid star formation in a few free-fall times could lead to gas expulsion.

Abstract

We investigate the effects of radiation pressure from stars on the survival of the star-forming giant clumps in high-redshift massive disc galaxies, during the most active phase of galaxy formation. The clumps, typically of mass ~10^8-10^9 Msun and radius ~0.5-1, are formed in the turbulent gas-rich discs by violent gravitational instability and then migrate into a central bulge in ~10 dynamical times. We show that the survival or disruption of these clumps under the influence of stellar feedback depends critically on the rate at which they form stars. If they convert a few percent of their gas mass to stars per free-fall time, as observed for all local star-forming systems and implied by the Kennicutt-Schmidt law, they cannot be disrupted. Only if clumps convert most of their mass to stars in a few free-fall times can feedback produce significant gas expulsion. We consider whether such rapid star formation is likely in high-redshift giant clumps.