Ram pressure stripping of HI-rich galaxies infalling into massive clusters

TL;DR

This study quantifies ram pressure stripping effects on HI-rich galaxies infalling into massive clusters, revealing significant gas loss and star formation changes even before reaching cluster cores.

Contribution

It provides the first detailed estimation of ram pressure stripping strength on HI-rich galaxies in X-ray detected clusters, highlighting environmental impact beyond cluster centers.

Findings

Galaxies under stronger RPS show reduced HI mass and increased central SFR.

Approximately 40% of HI-rich galaxies experience significant RPS effects at R200.

RPS influences galaxies well outside the cluster core, even beyond R200.

Abstract

We estimate the strength of ram pressure stripping (RPS) for HI-rich galaxies in X-ray detected clusters. We find that galaxies under stronger RPS tend to show more significantly reduced total HI mass and enhanced central SFR, compared to control galaxies in the field which have similar stellar mass, stellar surface density and integral star formation rate. Galaxies under strong or weak RPS account for around 40% of the HI-rich population at R200, and even beyond R200 in the most massive clusters. Our results imply the important role of RPS as a channel of environmental processing far before the galaxies reach the core region of clusters.