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Author Ciotti, Luca ♦ Pellegrini, Silvia
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ACCRETION DISKS ♦ ANALYTICAL SOLUTION ♦ ASTROPHYSICS ♦ BLACK HOLES ♦ EVALUATION ♦ HYDRODYNAMIC MODEL ♦ HYPOTHESIS ♦ MASS ♦ RADIATION PRESSURE ♦ SIMULATION ♦ X RADIATION ♦ X-RAY GALAXIES
Abstract One of the most active fields of research of modern-day astrophysics is that of massive black hole formation and coevolution with the host galaxy. In these investigations, ranging from cosmological simulations, to semi-analytical modeling, to observational studies, the Bondi solution for accretion on a central point-mass is widely adopted. In this work we generalize the classical Bondi accretion theory to take into account the effects of the gravitational potential of the host galaxy, and of radiation pressure in the optically thin limit. Then, we present the fully analytical solution, in terms of the Lambert–Euler W -function, for isothermal accretion in Jaffe and Hernquist galaxies with a central black hole. The flow structure is found to be sensitive to the shape of the mass profile of the host galaxy. These results and the formulae that are provided, most importantly, the one for the critical accretion parameter, allow for a direct evaluation of all flow properties, and are then useful for the abovementioned studies. As an application, we examine the departure from the true mass accretion rate of estimates obtained using the gas properties at various distances from the black hole, under the hypothesis of classical Bondi accretion. An overestimate is obtained from regions close to the black hole, and an underestimate outside a few Bondi radii; the exact position of the transition between the two kinds of departure depends on the galaxy model.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-10-10
Publisher Place United States
Journal Astrophysical Journal
Volume Number 848
Issue Number 1


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