X-ray spectroscopy and time variability of Narrow Line Seyfert 1

We present the main results of broad band (0.1-10 keV) BeppoSAX observations of a selected sample of Narrow Line Seyfert 1 galaxies (NLS1s). We have performed a spectroscopic analysis of LECS and MECS data to test their average spectral properties, and timing analysis to study their amplitude variability. The steep average spectral indices and the high amplitude time variability are in agreement with a scenario where NLS1s, with respect to the Broad Line Seyfert 1 (BLS1s) host a smaller black hole mass surrounded by hotter accretion disc.