Multi-Wavelength Studies of Spectacular Ram Pressure Stripping of a Galaxy: Discovery of an X-ray Absorption Feature

TL;DR

This study uses multi-wavelength observations to identify and analyze an X-ray absorption feature associated with ram pressure stripping in the Virgo cluster, revealing interactions between cold and hot gas in galaxy environments.

Contribution

It presents the first detection of an X-ray absorption feature linked to ram pressure stripping, providing insights into gas interactions in galaxy clusters.

Findings

Detected an X-ray absorption feature near M86 with a column density of 2-3 E20 /cm^2.

Identified an X-ray counterpart of the HI cloud with a temperature of 0.89 keV and a mass of ~4.5 E8 solar masses.

Found evidence of significant evaporation of HI gas likely due to thermal conduction from hot cluster plasma.

Abstract

We report the detection of an X-ray absorption feature near the galaxy M86 in the Virgo cluster. The absorber has a column density of 2-3 E20 /cm^2, and its position coincides with the peak of an intracluster HI cloud which was removed from the galaxy NGC 4388 presumably by ram pressure. These results indicate that the HI cloud is located in front of M86 along the line-of-sight, and suggest that the stripping was primarily created by an interaction between NGC 4388 and the hot plasmas of the Virgo cluster, not the M86 halo. By calculating an X-ray temperature map, we further detected an X-ray counterpart of the HI cloud up to about 3' south of M86. It has a temperature of 0.89 keV and a mass of ~4.5 E8 solar mass, exceeding the estimated HI gas mass. The high hot-to-cold gas ratio in the cloud indicates a significant evaporation of the HI gas, probably by thermal conduction from the hotter cluster plasma with a sub-Spitzer rate.