ROSAT HRI observations of six early-type galaxies

High-resolution ROSAT HRI soft X-ray observations of four E/S0 galaxies were conducted by us. The data show no signs of Seyfert activity in the X-ray regime. The central emission peaks of the four galaxies, NGC533, NGC2832, NGC4104 and NGC6329, are associated with their cooling flows. The half intensity radii of the cooling flows range from 0.8 to 3.5 kpc. We find a trend (based up to now on only five objects) of the radio power of the cores in E/S0 galaxies to increase with the size and the accretion rates of their cooling flows. In one galaxy, NGC4921, no centrally peaked extended gaseous envelope was found, which is most likely due to the fact that it is not an E/S0 galaxy, but an early-type spiral. NGC2885, the sixth galaxy in our initial sample, shows signs of X-ray emission from an AGN. It has also been classified as a Sy-1 AGN by Bade et al. (1995). However, optical imaging suggests that this galaxy is probably not an E or S0 type system either, but rather an early-type spiral galaxy. Thus, in the context of accretion rate vs. galaxy type models of low-luminosity AGNs, the presence of an X-ray luminous Sy-1 nucleus in NGC2885 is no surprise.