Accretion Discs with Accreting Coronae in Agn { Ii. Nuclear Wind

نویسنده

  • Hans J. Witt
چکیده

We study an accretion disc with a hot continuous corona. We assume that the corona itself accretes and therefore it is powered directly by the release of the gravitational energy and cooled by radiative interaction with the disc. We consider the vertical structure of such a corona and show that the radial infall is accompanied by strong vertical outtow. Such a model has two important consequences: (i) at a given radius the corona forms only for accretion rate larger than the limiting value and the fraction of energy dissipated in the corona decreases with increasing accretion rate, and (ii) the disc spectra are signiicantly softer in the optical/UV band in comparison with the predictions of standard accretion discs due to the mass loss and the decrease of internal dissipation in the disc. Both trends correspond well to the mean spectra of radio quiet AGN and observed luminosity states in galactic black hole candidates.

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تاریخ انتشار 2008