NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-20 T05:52:29 PDT
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For refcode 2014ApJ...791...74M:
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Copyright by American Astronomical Society. Reproduced by permission
2014ApJ...791...74M X-Ray Variability and the Inner Region in Active Galactic Nuclei Mohan, P.; Mangalam, A. Abstract. We present theoretical models of X-ray variability attributable to orbital signatures from an accretion disk including emission region size, quasi-periodic oscillations (QPOs), and its quality factor Q, and the emergence of a break frequency in the power spectral density shape. We find a fractional variability amplitude of F_{var}_ is proportional to M^{-0.4}_{{bullet}}_. We conduct a time series analysis on X-ray light curves (0.3-10 keV) of a sample of active galactic nuclei (AGNs). A statistically significant bend frequency is inferred in 9 of 58 light curves (16%) from 3 AGNs for which the break timescale is consistent with the reported BH spin but not with the reported BH mass. Upper limits of 2.85 x 10^7^ M_sun_ in NGC 4051, 8.02 x 10^7^ M_sun_ in MRK 766, and 4.68 x 10^7^ M_sun_ in MCG-6-30-15 are inferred for maximally spinning BHs. For REJ 1034+396 where a QPO at 3733 s was reported, we obtain an emission region size of (6-6.5) M and a BH spin of a <~ 0.08. The relativistic inner region of a thin disk, dominated by radiation pressure and electron scattering, is likely to host the orbital features as the simulated Q ranges from 6.3 x 10^-2^ to 4.25 x 10^6^, containing the observed Q. The derived value of Q ~ 32 for REJ 1034+396 therefore suggests that the AGN hosts a thin disk. Key words: accretion, accretion disks, black hole physics, galaxies: active, galaxies: Seyfert, methods: statistical
Retrieve 16 NED objects in this reference.
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