H I imaging of galaxies in X-ray bright groups

Abstract

ABSTRACT Environment plays an important role in the evolution of the gas contents of galaxies. Gasdeficiency of cluster spirals and the role of the hot intraclu ster medium (ICM) in strippinggas from these galaxies is a well studied subject. Loose groups with diffuse X-ray emmisionfrom the intragroup medium (IGM) offer an intermediate environment between clusters andgroups without a hot IGM. These X-ray bright groups have smaller velocity dispersion andlower temperature than clusters, but higher IGM density than loose groups without diffuseX-ray emission. A single dish comparative study of loose groups with and without diffuseX-ray emission from the IGM, showed that the galaxies in X-ray bright groups have lost moregas on average than the galaxies in non X-ray bright groups. In this paper we present GMRTHobservations of 13 galaxies from 4 X-ray bright groups: NGC5044, NGC720, NGC1550and IC1459. The aim of this work is to study the morphology of Hin these galaxies andto see if the hot IGM has in any way affected their Hcontent or distribution. In addition todisturbed Hmorphology,we find that most galaxies have shrunken H disks compared to thefield spirals. This indicates that IGM assisted stripping pr ocesses like ram pressure may havestripped gas from the outer edges of the galaxies.Key words: galaxies:evolution-galaxies:interactions-radiolines:galaxies-X-rays:galaxies