Black hole masses in NLS1 galaxies from the X-ray excess variance method
  We estimate black hole masses in Narrow Line Seyfert 1 (NLS1) galaxies at the basis of their X-ray excess variance. We apply the standard approach appropriate for Broad Line Seyfert 1 (BLS1) galaxies. In general, we find that the obtained masses are by a factor \sim 20 too small to agree with values obtained from other methods (reverberation, stellar dispersion). However, a small subset of our NLS1 objects does not require that multiplication, or the correction factor is less than 4. We find that this subset have a soft X-ray photon index, \Gamma_{0.1-2.4 keV}, smaller than 2. We thus postulate that this subclass of NLS1 actually belongs to BLS1. 
M. Nikolajuk (1), P. Gurynowicz (1), and B. Czerny (2), ((1)Univ. of   Bialystok, Poland, (2) N. Copernicus Astronomical Cen...