1111.3569 (Kazem Faghei)
Kazem Faghei
The purpose of this paper is to explore the dynamical behaviour of hot
accretion flow with thermal conduction. The importance of thermal conduction on
hot accretion flow is confirmed by observations of the hot gas that surrounds
Sgr A$^*$ and a few other nearby galactic nuclei. In this research, the effect
of thermal conduction is studied by a saturated form of it, as is appropriate
for weakly collisional systems. The angular momentum transport is assumed to be
a result of viscous turbulence and the $\alpha$-prescription is used for the
kinematic coefficient of viscosity. The equations of accretion flow are solved
in a simplified one-dimensional model that neglects the latitudinal dependence
of the flow. To solve the integrated equations that govern the dynamical
behaviour of the accretion flow, we have used an unsteady self-similar
solution. The solution provides some insights into the dynamics of
quasi-spherical accretion flow and avoids from limits of the steady
self-similar solution. In comparison to accretion flows without thermal
conduction, the disc generally becomes cooler and denser. These properties are
qualitatively consistent with performed simulations in hot accretion flows.
Moreover, the angular velocity increases with the magnitude of conduction,
while the radial infall velocity decreases. The mass accretion rate onto the
central object is reduced in the presence of thermal conduction. We found that
the viscosity and thermal conduction have the opposite effects on the physical
variables. Furthermore, the flow represents a transonic point that moves inward
with the magnitude of conduction or viscosity.
View original:
http://arxiv.org/abs/1111.3569
No comments:
Post a Comment