Radiative non-isothermal Bondi accretion onto a massive black hole. (arXiv:1902.00360v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ramirez_Velasquez_J/0/1/0/all/0/1">J. M. Ramirez-Velasquez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sigalotti_L/0/1/0/all/0/1">L. Di G. Sigalotti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gabbasov_R/0/1/0/all/0/1">R. Gabbasov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cruz_F/0/1/0/all/0/1">F. Cruz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Klapp_J/0/1/0/all/0/1">J. Klapp</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Contreras_E/0/1/0/all/0/1">Ernesto Contreras</a>
In this paper, we present a generalization of the classical Bondi accretion
theory for the case of non-isothermal accretion processes onto a supermassive
black hole (SMBH), including the effects of X-ray heating and the radiation
force due to electron scattering and spectral lines. The radiation field is
calculated by considering an optically thick, geometrically thin, standard
accretion disk as the emitter of UV photons and a spherical central object as a
source of X-ray emission. In the present analysis, the UV emission from the
accretion disk is assumed to have an angular dependence, while the
X-ray/central object radiation is assumed to be isotropic. The influence of
both types of radiation is evaluated for different flux fractions of the X-ray
and UV emissions with and without the effects of spectral line driving. We find
that the radiation emitted near the SMBH interacts with the infalling matter
and modifies the accretion dynamics. In the presence of line driving, a
transition from pure accretion to outflows takes place regardless of whether or
not the UV emission dominates over the X-ray emission. Estimated values of the
accretion radius and accretion rate in terms of the classical Bondi values are
also given. The results are useful for the construction of proper initial
conditions for time-dependent hydrodynamical simulations of accretion flows
onto SMBH at the centre of galaxies.
In this paper, we present a generalization of the classical Bondi accretion
theory for the case of non-isothermal accretion processes onto a supermassive
black hole (SMBH), including the effects of X-ray heating and the radiation
force due to electron scattering and spectral lines. The radiation field is
calculated by considering an optically thick, geometrically thin, standard
accretion disk as the emitter of UV photons and a spherical central object as a
source of X-ray emission. In the present analysis, the UV emission from the
accretion disk is assumed to have an angular dependence, while the
X-ray/central object radiation is assumed to be isotropic. The influence of
both types of radiation is evaluated for different flux fractions of the X-ray
and UV emissions with and without the effects of spectral line driving. We find
that the radiation emitted near the SMBH interacts with the infalling matter
and modifies the accretion dynamics. In the presence of line driving, a
transition from pure accretion to outflows takes place regardless of whether or
not the UV emission dominates over the X-ray emission. Estimated values of the
accretion radius and accretion rate in terms of the classical Bondi values are
also given. The results are useful for the construction of proper initial
conditions for time-dependent hydrodynamical simulations of accretion flows
onto SMBH at the centre of galaxies.
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