ABSTRACT

Preliminary results of a search for gas transfer between the galaxies in E+S pairs are presented. In the pair considered K542, ionized gas is detected in the nucleus of the elliptical but no gas in the process of being transferred between the two components has been found.

INTRODUCTION

In the past ten years observations of the ionized (Phillips et al. 1986) and HI (Knapp et al. 1985) gas content of early type galaxies have shown that 50-60% of these galaxies contain a modest amount of interstellar gas. On the basis of the H I data, Knapp and coworkers have suggested that the interstellar gas in ellipticals may be of external origin. At least two external sources for the gas have been suggested: the capture of small gas-rich companions and accretion from nearby gas-rich galaxies. Mixed morphology E+S pairs make an ideal laboratory to test the second hypothesis, since the presumed external source for the gas is relatively unambigous. Two possible strategies exist to test the hypothesis, 1) define a sample of E+S pairs and a control sample of isolated ellipticals and compare the global gas content of the two samples, or 2) examine a sample of E+S pairs that are likely candidates to be currently crossfueling and attempt to catch them in the act. We have chosen the second strategy, since optical spectra had already been obtained for several E+S pairs.