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Related papers: Preheated Advection Dominated Accretion Flow

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We calculate the structure of accretion disc around a rapidly rotating black hole with a super-Eddington accretion rate. The luminosity and height of the disc are reduced by the advection effect. In the case of a large viscosity parameter,…

Astrophysics · Physics 2009-10-30 Andrei M. Beloborodov

The concept of an advection-dominated accretion flow (ADAF), with or without wind loss, was used to describe the spectra of the galactic center source Sgr A*, low-luminosity AGN and nuclei of elliptical galaxies (including M87). The…

Astrophysics · Physics 2009-11-06 Bifang Liu , Emmi Meyer-Hofmeister

We present self-similar solutions for advection-dominated accretion flows with radial viscous force in the presence of outflows from the accretion flow or infall. The axisymmetric flow is treated in variables integrated over polar sections…

Astrophysics · Physics 2009-10-31 Thomas Beckert

We investigate the dynamics of clumps that coexisted with/in advection-dominated accretion flows by considering thermal conductivity. Thermal conduction can be one of the effective factors in the energy transportation of ADAFs; hence it may…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Hussein Ayad , Maryam Samadi , Shahram Abbassi

In a series of our previous works, a model of radiatively inefficient accretion flows (RIAFs) in a global magnetic field (so called resistive RIAF model) has proved its ability to account for many physical processes taking place in such…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Osamu Kaburaki

Advection-dominated accretion flows (ADAFs) are known to be convectively unstable for low values of the viscosity parameter alpha. Two-dimensional axisymmetric hydrodynamic simulations of such flows reveal a radial density profile which is…

Astrophysics · Physics 2009-10-31 Igor V. Igumenshchev , Marek A. Abramowicz , Ramesh Narayan

Transitional disks are protoplanetary disk around young stars that display inner holes in the dust distribution within a few AU, which is accompanied nevertheless by some gas accretion onto the central star. These cavities could possibly be…

Earth and Planetary Astrophysics · Physics 2013-12-03 Tobias W. A. Müller , Wilhelm Kley

We present global solutions that describe advection-dominated accretion flows around black holes. The solutions are obtained by numerically solving a set of coupled ordinary differential equations corresponding to a steady axisymmetric…

Astrophysics · Physics 2009-10-28 Ramesh Narayan , Shoji Kato , Fumio Honma

We present here the solutions of magnetized accretion flows on to a compact object with hard surface such as neutron stars. The magnetic field of the central star is assumed dipolar and the magnetic axis is assumed to be aligned with the…

High Energy Astrophysical Phenomena · Physics 2018-03-14 Kuldeep Singh , Indranil Chattopadhyay

We study the effects of accretion environment (gas density, temperature and angular momentum) at large radii ($\sim 10$pc) on luminosity of hot accretion flows. The radiative feedback effects from the accretion flow on the accretion…

High Energy Astrophysical Phenomena · Physics 2018-01-24 Xiao-Hong Yang , De-Fu Bu

We study radiative properties of hot accretion flows in a general relativistic model with an exact treatment of global Comptonization, developed in our recent works. We note a strong dependence of electron temperature on the strength of…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Andrzej Niedzwiecki , Fu-Guo Xie , Agnieszka Stepnik

The broad-line region (BLR) disappears in many low-luminosity AGNs, the reason of which is still controversial. The BLRs in AGNs are believed to be associated with the outflows from the accretion disks. Most of the low-luminosity AGNs…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Xinwu Cao

In the past years, several observations of AGN and X-ray binaries have suggested the existence of a warm T around 0.5-1 keV and optically thick, \tau ~ 10-20, corona covering the inner parts of the accretion disk. These properties are…

Astrophysics of Galaxies · Physics 2015-08-05 A. Rozanska , J. Malzac , R. Belmont , B. Czerny , P. -O. Petrucci

We characterize the nature of thin, axisymmetric, inviscid, accretion flows of cold adiabatic gas with zero specific energy in the vicinity of a black hole by the specific angular momentum. Using two-dimensional hydrodynamic simulations in…

Astrophysics · Physics 2009-10-28 Dongsu Ryu , Sandip K. Chakrabarti , Diego Molteni

We present axisymmetric numerical simulations of radiatively inefficient accretion flows onto black holes combining general relativity, magnetohydrodynamics, self-consistent electron thermodynamics, and frequency-dependent radiation…

High Energy Astrophysical Phenomena · Physics 2017-08-09 Benjamin R. Ryan , Sean M. Ressler , Joshua C. Dolence , Alexander Tchekhovskoy , Charles F. Gammie , Eliot Quataert

(Abridged) A new type of self-similar hot viscous radiative accretion flow onto a rapidly spinning neutron star has recently been discovered. This ``hot brake'' flow forms in the two-temperature zone (close to a central object), but at a…

Astrophysics · Physics 2007-05-23 Mikhail V. Medvedev

Wind is believed to be widespread in various black hole accretion flows. However, unlike the wind from thin disks, which have substantial observational evidence, the wind from hot accretion flows is difficult to observe due to the extremely…

High Energy Astrophysical Phenomena · Physics 2024-08-30 Hai Yang , Feng Yuan

When a black hole accretes plasmas at very low accretion rate, an advection-dominated accretion flow (ADAF) is formed. In an ADAF, relativistic electrons emit soft gamma-rays via Bremsstrahlung. Some MeV photons collide with each other to…

High Energy Astrophysical Phenomena · Physics 2018-11-26 Kouichi Hirotani

We extend and reconcile recent work on turbulence and particle heating in advection-dominated accretion flows. For approximately equipartition magnetic fields, the turbulence primarily heats the electrons. For weaker magnetic fields, the…

Astrophysics · Physics 2009-10-30 Eliot Quataert , Andrei Gruzinov

We perform non-hydrodynamical 2.5D simulations to study the dynamics of material above accretion disk based on the disk radiation pressure acting on dust. We assume a super-accreting underlying disk with the accretion rate of 10 times the…

Astrophysics of Galaxies · Physics 2022-09-21 Mohammad-Hassan Naddaf , Bożena Czerny , Michal Zajaček