DISTRIBUTION OF IONIZED-GAS IN X-RAY BRIGHT EARLY-TYPE GALAXIES

We report imaging observations of H alpha+[N II] nebulosities in seven early type galaxies viz., NGC 1399, NGC 1600, NGC 2563, NGC 4203, NGC 4636, NGC 4753 acid NGC 5044. These are primarily X-ray bright galaxi es which are the dominant members of nearby groups. Many of these gala xies have X-ray cooling flows. The results are based on CCD surface ph otometry carried out using a broad-band filter R, and a narrow band fi lter appropriate for the red-shifted H alpha+[N II] emission. We prese nt the integrated H alpha luminosities in these galaxies and examine v arious emission mechanisms. The observed H alpha luminosity implies a mass of similar to 10(5) M. in the ionized gas. We suggest that photo- ionization by young stars is a viable emission mechanism and star form ation due to accretion events or mergers may be common in these galaxi es.