dc.contributor.author |
Mohan, Prashanth |
|
dc.contributor.author |
Mangalam, A |
|
dc.date.accessioned |
2014-07-31T05:57:09Z |
|
dc.date.available |
2014-07-31T05:57:09Z |
|
dc.date.issued |
2014-08-20 |
|
dc.identifier.citation |
The Astrophysical Journal, Vol. 791, No. 2, 74 |
en |
dc.identifier.issn |
0004-637X |
|
dc.identifier.uri |
http://hdl.handle.net/2248/6641 |
|
dc.description |
Restricted Access |
en |
dc.description.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 $F_{{\rm var}}\propto M^{-0.4}_{\bullet }$. 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 × 107 M ☉ in NGC 4051, 8.02 × 107 M ☉ in MRK 766, and 4.68 × 107 M ☉ 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 lsim 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 × 10–2 to 4.25 × 106, containing the observed Q. The derived value of Q ~ 32 for REJ 1034+396 therefore suggests that the AGN hosts a thin disk. |
en |
dc.language.iso |
en |
en |
dc.publisher |
IOP Publishing |
en |
dc.relation.uri |
http://dx.doi.org/10.1088/0004-637X/791/2/74 |
en |
dc.rights |
© IOP Publishing |
en |
dc.subject |
Accretion, accretion disks |
en |
dc.subject |
Black hole physics |
en |
dc.subject |
Galaxies: active |
en |
dc.subject |
Galaxies: Seyfert |
en |
dc.subject |
Methods: statistical |
en |
dc.title |
X-ray variability and the inner region in active galactic nuclei |
en |
dc.type |
Article |
en |