Poster Presentation

Study the X-ray variability of Active Galactic Nuclei

Author(s): Haiwu Pan (National Astronomical Observatories, Chinese Academy of Sciences)

Presenter: Haiwu Pan (National Astronomical Observatories, Chinese Academy of Sciences)

Rapid X-ray variability is one of the basic observational characteristics of active galactic nuclei (AGNs). It is a useful tool to study black holes (BHs) and the central engine of AGN, since the X-ray emission is thought to originate from the innermost region of an accretion flow around the BH. In this talk, we will report on the detection of an X-ray QPO signal with a period of 3800s at a confidence level >99.99%. The central BH mass have been estimated from the optical spectra. The QPO follows closely the universal scaling relation between QPO frequency and BH mass, which spans from stellar-mass to supermassive BHs. Besides, we estimate the BH mass of the γ-ray detected narrow-line Seyfert 1 (NLS1) 1H0323+342 from X-ray variability. Our results independently confirm that 1H0323+342 harbors a ∼ 1e7 solar masses BH similar to those in normal NLS1s rather than those in blazars.