Summary
We consider a «two phase» accretion disk consisting of an optically thick layer with temperatureT≃104 K embedded in a hot thin corona (T≃109 K). The main energy input occurs through magnetic heating of the electrons in the corona, while cooling is due to Compton losses of the hot electrons on the soft photons provided by the thick layer. We write the balance equations for the two phases. We show that a possible mode of variability yields steeper spectra for increasing soft-photon luminosity as observed in Seyfert galaxies and compute composite model spectra in the X-ray range, via Monte Carlo simulations.
Similar content being viewed by others
References
G. Ghisellini: inVariability of active galactic nuclei, Atlanta, May 2–4, 1990, edited byR. H. Miller andP. J. Wiita (Cambridge University Press, 1991), p. 236.
A. A. Zdziarski, G. Ghisellini, I. G. George, A. C. Fabian, R. Svensson andC. Done:Astrophys. J.,363, L1 (1990).
H. Burm:Astron. Astrophys.,165, 220 (1986).
L. A. Pozdnyakov, I. M. Sobol, andR. A. Syunyaev: inSoviet Scientific Reviews, Astrophysics and Space Physics, edited byR. A. Syunyaev (Harwood Academic Publishers, New York, 1983), Vol. II, p. 189.
A. P. Lightman andT. R. White:Astrophys. J.,335, 57 (1988).
P. W. Guilbert andM. J. Rees:Mon. Not. R. Astron. Soc.,233, 475 (1988).
A. A. Zdziarski:Astrophys. J.,289, 514 (1985).
A. Treves, G. Bonelli, L. Chiappetti, R. Falomo, L. Maraschi, G. Tagliaferri andE. G. Tanzi:Astrophys. J.,359, 98 (1990).
L. Maraschi, L. Chiappetti, R. Falomo, B. Garilli, M. Malken, G. Tagliaferri, E. G. Tanzi andA. Treves:Astrophys. J.,368, 138 (1991).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Haardt, F., Maraschi, L. X-Ray emission from two-phase accretion disks. Il Nuovo Cimento C 15, 831–837 (1992). https://doi.org/10.1007/BF02507858
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02507858