A theoretical study of the time-lags due to Comptonization and the constraints on the X-ray corona in AGN
| Autor: | Zhang, W., Papadakis, I. E., Dovčiak, M., Bursa, M., Karas, V. |
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| Rok vydání: | 2022 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stac3625 |
| Popis: | We study the Fourier time-lags due to the Comptonization of disc-emitted photons in a spherical, uniform, and stationary X-ray corona, which located on the rotational axis of the black hole. We use Monk, a general relativistic Monte-Carlo radiative transfer code, to calculate Compton scattering of photons emitted by a thin disc with a Novikov-Thorne temperature profile. We find that the model time-lags due to Comptonization remain constant up to a characteristic frequency and then rapidly decrease to zero at higher frequencies. We provide equations which can be used to determine the time-lags and cross spectra for a wide range of values for the corona radius, temperature, optical depth, height, and for various accretion rates and black hole masses. We also provide an equation for the X-ray luminosity of a single corona, as a function of the its characteristics and location above the disc. Remarkably, the observed X-ray time-lags of nearby, bright active galaxies can be successfully reproduced by inverse Comptonization process of multiple dynamic coronae. Comment: 16 pages, 17 figures; accepted for publication in MNRAS |
| Databáze: | arXiv |
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