Modelling of the X-ray broad absorption features in Narrow-Line Seyfert   1s
  We investigate the origin of the broad absorption features detected near 1-1.4 keV in several Narrow Line Seyfert 1 galaxies, by modelling the absorbing medium with various physical parameters, using the ionization code PEGAS. The observed properties of the X-ray absorption features can be reproduced by taking into account the peculiar soft X-ray excess which is well fitted by a blackbody plus an underlying power law. We equally stress that the emission coming from the absorbing medium (related to the covering factor) has a strong influence on the resulting X-ray spectrum, in particular on the apparent position and depth of the absorption features. A non-solar iron abundance may be required to explain the observed deep absorption. We also investigate the influence of an additional collisional ionization process (hybrid case) on the predicted absorption features. 
D. Porquet (1), M. Mouchet (2), A.-M. Dumont (2) ((1) Service   d'Astrophysique, Saclay, (2) Observatoire de Paris, section ...