A WISE View of Star Formation in Local Galaxy Clusters

TL;DR

This study uses WISE 22 micron data to analyze star formation activity in 69 local galaxy clusters, revealing how star formation varies with radius and cluster mass.

Contribution

It provides a systematic analysis of star formation in galaxy clusters beyond R200 using infrared data, highlighting the weak dependence on cluster mass.

Findings

Star-forming galaxy fraction increases with radius but stays below field levels.

No strong correlation between cluster mass and total specific star formation rate.

Star formation activity is more influenced by local environment than cluster mass.

Abstract

We present results from a systematic study of star formation in local galaxy clusters using 22 micron data from the Wide-field Infrared Survey Explorer (WISE). The 69 systems in our sample are drawn from the Cluster Infall Regions Survey (CIRS), and all have robust mass determinations. The all-sky WISE data enables us to quantify the amount of star formation, as traced by 22 micron, as a function of radius well beyond R200, and investigate the dependence of total star formation rate upon cluster mass. We find that the fraction of star-forming galaxies increases with cluster radius but remains below the field value even at 3 R200. We also find that there is no strong correlation between the mass-normalized total specific star formation rate and cluster mass, indicating that the mass of the host cluster does not strongly influence the total star formation rate of cluster members.