36 - Diagnostics of the evolution of spiral galaxies in a cluster environment

Summary

We present X-ray and radio polarimetric observations of selected Virgo Cluster spiral galaxies. The X-ray extended emission traces hot-gas filaments in galactic halos and is sensitive to the environmental effects exerted by interactions inside the cluster, like ram-pressure stripping. The radio polarization studies provide clues about alignment, distortion, compression and strength of detected magnetic fields. When used together, the two types of observations constitute an excellent tool for examining disturbances in galactic disks and halos caused by interactions of galaxies with the intracluster medium or between the galaxies themselves. The coming of age of X-ray polarimetry could provide us with unprecedented tools to explore further the evolution of galaxies in a cluster environment.

Introduction

There are a number of environmental effects in clusters of galaxies that modify spiral galaxies causing their HI deficiency, Hα spatial truncation and distortions, as well as strong dynamical and morphological evolution[1]. They influence also galactic magnetic fields, which can be stretched and compressed while the distribution of the ISM is being changed. The Virgo Cluster is the best system to study such processes due to its proximity and large spiral galaxy content. In this work we investigate galaxy–galaxy and galaxy–ICM interactions in the Virgo Cluster in the radio and in the soft X-ray bands. We make use of the VLA and Effelsberg 100-m radio telescope to obtain high sensitivity for the extended total power and polarized nonthermal radio emission.