ACTIVE GALAXIES OBSERVED DURING THE EXTREME-ULTRAVIOLET EXPLORER ALL-SKY SURVEY

We present observations of active galactic nuclei (AGNs) obtained with the Extreme Ultraviolet Explorer (EUVE) during the all-sky survey. A total of 13 sources were detected at a significance of 2.5 sigma or be tter: seven Seyfert galaxies, five BL Lac objects, and one quasar. The fraction of BL Lac objects is higher in our sample than in hard X-ray surveys but is consistent with the soft X-ray Einstein Slew Survey, i ndicating that the main reason for the large number of BL Lac objects detected in the extreme ultraviolet (EUV) and soft X-ray bands is thei r steeper X-ray spectra. We show that the number of AGNs observed in b oth the EUVE and ROSAT Wide Field Camera surveys can readily be explai ned by modelling the EUV spectra with a simple power law in the case o f BL Lac objects and with an additional EUV excess in the case of Seyf erts and quasars. Allowing for cold matter absorption in Seyfert galax y hosts drive up the inferred average continuum slope to 2.0 +/- 0.5 ( at 90% confidence), compared to a slope of 1.0 usually found from soft X-ray data. If Seyfert galaxies without EUV excesses form a significa nt fraction of the population, then the average spectrum of those with bumps should be even steeper. We place a conservative limit on neutra l gas in BL Lac objects: N-H < 10(20) cm(-2).