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Paper: Black Hole Masses in NLS1 Galaxies from the X-ray Excess Variance Method
Volume: 373, The Central Engine of Active Galactic Nuclei
Page: 66
Authors: Nikolajuk, M.; Gurynowicz, P.; Czerny, B.
Abstract: We estimate black hole masses in narrow-line Seyfert 1 (NLS1) galaxies on 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 ~ 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, Γ0.1−2.4keV, smaller than 2. We thus postulate that this subclass of NLS1 actually belongs to BLS1.
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