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Short-Term X-ray Variability during Different Activity Phases of Blazars S5 0716+714 and PKS 2155-304
Article

A Relativistic Orbit Model for Temporal Properties of AGN

by and *,†
Indian Institute of Astrophysics, Sarjapur Road, 2nd Block Koramangala, Bangalore 560034, India
*
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Galaxies 2020, 8(3), 67; https://doi.org/10.3390/galaxies8030067
Received: 27 July 2020 / Revised: 7 September 2020 / Accepted: 7 September 2020 / Published: 11 September 2020
(This article belongs to the Special Issue X-Ray Flux and Spectral Variability of Blazars)
We present a unified model for X-ray quasi-periodic oscillations (QPOs) seen in Narrow-line Seyfert 1 (NLSy1) galaxies, γ-ray and optical band QPOs that are seen in Blazars. The origin of these QPOs is attributed to the plasma motion in corona or jets of these AGN. In the case of X-ray QPOs, we applied the general relativistic precession model for the two simultaneous QPOs seen in NLSy1 1H 0707-945 and deduce orbital parameters, such the radius of the emission region, and spin parameter a for a circular orbit; we obtained the Carter’s constant Q, a, and the radius in the case of a spherical orbit solution. In other cases where only one X-ray QPO is seen, we localized the orbital parameters for NLSy1 galaxies REJ 1034+396, 2XMM J123103.2+110648, MS 2254.9-3712, Mrk 766, and MCG-06-30-15. By applying the lighthouse model, we found that a kinematic origin of the jet based γ-ray and optical QPOs, in a relativistic MHD framework, is possible. Based on the inbuilt Hamiltonian formulation with a power-law distribution in the orbital energy of the plasma consisting of only circular or spherical trajectories, we show that the resulting Fourier power spectral density (PSD) has a break corresponding to the energy at ISCO. Further, we derive connection formulae between the slopes in the PSD and that of the energy distribution. Overall, given the preliminary but promising results of these relativistic orbit models to match the observed QPO frequencies and PSD at diverse scales in the inner corona and the jet, it motivates us to build detailed models, including a transfer function for the energy spectrum in the corona and relativistic MHD jet models for plasma flow and its polarization properties. View Full-Text
Keywords: kerr black holes; active galaxies; BL Lacertae object: BL Lac; seyfert galaxies; jets; accretion disk kerr black holes; active galaxies; BL Lacertae object: BL Lac; seyfert galaxies; jets; accretion disk
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MDPI and ACS Style

Rana, P.; Mangalam, A. A Relativistic Orbit Model for Temporal Properties of AGN. Galaxies 2020, 8, 67. https://doi.org/10.3390/galaxies8030067

AMA Style

Rana P, Mangalam A. A Relativistic Orbit Model for Temporal Properties of AGN. Galaxies. 2020; 8(3):67. https://doi.org/10.3390/galaxies8030067

Chicago/Turabian Style

Rana, Prerna, and A. Mangalam. 2020. "A Relativistic Orbit Model for Temporal Properties of AGN" Galaxies 8, no. 3: 67. https://doi.org/10.3390/galaxies8030067

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