In order to study the origin of the soft excess of Narrow-Line Seyfert1 Galaxies, 7 objects observed with XMM-Newton are analyzed. The soft excess is found to have mildly convex shape, which is successfully reproduced by a power-law with an exponential cutoff. It can be interpreted as disk Comptonization by cool and relatively optically thick plasma based on an analogy with Galactic black holes under high accretion rates.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)