BEPPOSAX OBSERVATIONS OF NARROW-LINE SEYFERT-1 GALAXIES

We report on the first spectrum up to 10 keV of the bright narrow-line Seyfert 1 galaxy Ton S 180, obtained with the imaging instruments onb oard BeppoSAX. This is the first observed source in a sample of a doze n narrow-line Seyfert 1 galaxies in the BeppoSAX Core Program, We also present and discuss a high quality optical spectrum taken at the 1.5 m telescope at La Silla two months before the BeppoSAX observation. Th e X-ray spectrum shows a clear hardening above about 2 keV, where a po wer law with Gamma similar or equal to 2.3 plus an iron line provide a good description of the data. This slope is significantly steeper tha n the typical one for classical Seyfert 1's and quasars. The best fit line energy is suggestive of highly ionized iron, which would support the idea that the high accretion rate is (one of) the fundamental para meter(s) characterizing the Narrow Line Seyfert 1 phenomenon.