Metal Enrichment via Ram Pressure Stripping in the IGM of the Compact Galaxy Group RGH 80

TL;DR

This study uses high-quality Chandra data to identify a high-metallicity arc in the RGH 80 galaxy group, demonstrating that ram pressure stripping can enrich the intergalactic medium with metals by removing the ISM from member galaxies.

Contribution

It provides the first detailed X-ray evidence that ram pressure stripping enriches the IGM in galaxy groups, similar to processes observed in galaxy clusters.

Findings

High-abundance arc detected near PGC 046529

The arc's properties match those of the galaxy's ISM

Ram pressure stripping effectively enriches the IGM in groups

Abstract

By creating and analyzing the two dimensional gas temperature and abundance maps of the RGH 80 compact galaxy group with the high-quality Chandra data, we detect a high-abundance ($\simeq 0.7$ $Z_\odot$) arc, where the metal abundance is significantly higher than the surrounding regions by $\simeq 0.3$ Z_\odot$. This structure shows tight spatial correlations with the member galaxy PGC 046529, as well as with the arm-like feature identified on the X-ray image in the previous work of Randall et al. (2009). Since no apparent signature of AGN activity is found associated with PGC 046529 in multi-band observations, and the gas temperature, metallicity, and mass of the high-abundance arc resemble those of the ISM of typical early-type galaxies, we conclude that this high-abundance structure is the remnant of the ISM of PGC 046529, which was stripped out of the galaxy by ram pressure stripping due to the motion of PGC 046529 in RGH 80. This novel case shows that ram pressure stripping can work efficiently in the metal enrichment process in galaxy groups, as it can in galaxy clusters.