The Fate of Stellar Mass Loss in Central Cluster Galaxies

TL;DR

This paper investigates whether stellar mass loss can account for the star-forming gas in central cluster galaxies, finding that stellar winds provide sufficient material and may remain cool enough to sustain observed dust properties.

Contribution

It demonstrates that stellar mass loss rates are comparable to star-formation rates and argues that this gas can stay cool and dust-rich in high-pressure cluster environments.

Findings

Stellar mass loss can supply enough gas for star formation in most central cluster galaxies.

Gas shed by stars may remain cool and dust-rich in high-pressure cluster cores.

Stellar winds are a significant, previously underappreciated source of star-forming material.

Abstract

Star formation within the central galaxies of galaxy clusters is often interpreted as being fueled by cooling of the hot intracluster medium. However, the star-forming gas is dusty, and Spitzer spectra show that the dust properties are similar to those in more normal star-forming environments, in which the dust has come from the winds of dying stars. Here we consider whether the primary source of the star-forming gas in central cluster galaxies could be normal stellar mass loss. We show that the overall stellar mass-loss rate in a large central galaxy (~4-8 solar masses per year) is at least as large as the observed star-formation rates in all but the most extreme cases and must be included in any assessment of the gas-mass budget of a central cluster galaxy. We also present arguments suggesting that the gas shed by stars in galaxy clusters with high core pressures and short central cooling times may remain cool and distinct from its hot surroundings, thereby preserving the dust within it.