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We consider the role of advection in the two-temperature accreting corona with an underlying optically thick disc. The properties of coronal solutions depend significantly on the description of advection. Local parameterization of advection…

Astrophysics · Physics 2009-10-31 Agnieszka Janiuk , Piotr T. Zycki , Bozena Czerny

Radiatively inefficient, hot accretion flows are widely considered as a relevant accretion mode in low-luminosity AGNs. We study spectral formation in such flows using a refined model with a fully general relativistic description of both…

High Energy Astrophysical Phenomena · Physics 2014-04-07 Andrzej Niedzwiecki , Fu-Guo Xie , Agnieszka Stepnik

We study low-density axisymmetric accretion flows onto black holes (BHs) with two-dimensional hydrodynamical simulations, adopting the $\alpha$-viscosity prescription. When the gas angular momentum is low enough to form a rotationally…

Astrophysics of Galaxies · Physics 2018-09-18 Kohei Inayoshi , Jeremiah P. Ostriker , Zoltan Haiman , Rolf Kuiper

We study outflows driven by Active Galactic Nuclei (AGNs) using high- resolution simulations of idealized z=2 isolated disk galaxies. Episodic accretion events lead to outflows with velocities >1000 km/s and mass outflow rates up to the…

Astrophysics of Galaxies · Physics 2015-06-18 Jared M. Gabor , Frédéric Bournaud

We study the radiatively driven fluid jets around a non-rotating black hole. The radiation arising from the inner compact corona and outer sub-Keplerian part of the disc accelerates the jets. We obtain the steady state, semi-analytical,…

High Energy Astrophysical Phenomena · Physics 2021-11-17 RajKishor Joshi , Indranil Chattopadhyay , Lallan Yadav

We explore the effects of anisotropic thermal conduction, anisotropic pressure, and magnetic field strength on the hot accretion flows around black holes by solving the axisymmetric, steady-state magnetohydrodynamic equations. The…

High Energy Astrophysical Phenomena · Physics 2022-03-09 Amin Mosallanezhad , Fatemeh Zahra Zeraatgari , Liquan Mei , De-Fu Bu

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

General properties of advection-dominated accretion flows are discussed. Special emphasis is given to the optically thin branch of solutions, which has very high ion and electron temperatures and is thermally stable. This solution branch…

Astrophysics · Physics 2007-05-23 Ramesh Narayan

The existence of hot, two-temperature accretion flows is essential to the recent discussions of the low luminosity, hard X-ray emission from accreting neutron stars and black holes in Galactic binaries and massive black holes in low…

Astrophysics · Physics 2009-10-31 Jongmann Yang , Insu Yi

We perform one-dimensional radiation hydrodynamical simulations to solve accretion flows onto massive black holes (BHs) with a very high rate. Assuming that photon trapping limits the luminosity emerging from the central region to…

High Energy Astrophysical Phenomena · Physics 2016-09-07 Yuya Sakurai , Kohei Inayoshi , Zoltán Haiman

We study the coupled disc-jet system around the black hole where the outflow solutions are obtained in terms of the inflow parameters. We observe that an advective accretion disc can eject outflows/jets for wide range of viscosity…

High Energy Astrophysical Phenomena · Physics 2014-05-28 Santabrata Das , Indranil Chattopadhyay , Anuj Nandi , Biplob Sarkar

Observations and numerical magnetohydrodynamic (MHD) simulations indicate the existence of outflows and ordered large-scale magnetic fields in the inner region of hot accretion flows. In this paper we present the self-similar solutions for…

Astrophysics · Physics 2009-11-13 De-Fu Bu , Feng Yuan , Fu-Guo Xie

We study the structure and properties of hot MHD accretion onto a Kerr black hole. In such a system, the hole is magnetically coupled to the inflowing gas and exerts a torque onto the accretion flow. A hot settling flow can form around the…

Astrophysics · Physics 2011-05-10 Mikhail V. Medvedev , Norman Murray

We examine the properties of the outflowing matter from an advective accretion disc around a spinning black hole. During accretion, rotating matter experiences centrifugal pressure supported shock transition that effectively produces a…

High Energy Astrophysical Phenomena · Physics 2015-09-23 Ramiz Aktar , Santabrata Das , Anuj Nandi

We present a model of optically thin, two-temperature, accretion flows using an exact Monte Carlo treatment of global Comptonization, with seed photons from synchrotron and bremsstrahlung emission, as well as with a fully general…

High Energy Astrophysical Phenomena · Physics 2015-05-28 A. Niedzwiecki , F. -G. Xie , A. A. Zdziarski

We examine gas accretion and subsequent star formation in representative galaxies from the McMaster Unbiased Galaxy Simulations (Stinson et al. 2010). Accreted gas is bimodal with a natural temperature division at $10^5$ K, near the peak of…

Astrophysics of Galaxies · Physics 2014-07-23 Rory Woods , James Wadsley , Hugh M. P. Couchman , Greg Stinson , Sijing Shen

The global structure of optically thin advection dominated accretion flows which are composed of two-temperature plasma around black holes is calculated. We adopt the full set of basic equations including the advective energy transport in…

Astrophysics · Physics 2009-10-30 T. Manmoto , S. Mineshige , M. Kusunose

We have carried out fully relativistic numerical simulations of accretion disks in the Kerr metric. In this paper we focus on the unbound outflows that emerge self-consistently from the accretion flow. These outflows are found in the axial…

Astrophysics · Physics 2009-11-10 Jean-Pierre De Villiers , John F. Hawley , Julian H. Krolik , Shigenobu Hirose

The accretion of hot slowly rotating gas onto a supermassive black hole is considered. Rotation velocities at the Bondi radius r_B are small in comparison with speed of sound c_s. The centrifugal barrier at a depth r_c = l^2/G M_BH << r_B…

High Energy Astrophysical Phenomena · Physics 2011-01-31 N. A. Inogamov , R. A. Sunyaev

We studied the outflow behaviour from accretion discs around black holes taking into account the vertical equilibrium accretion flow model. The outflow rate is found to depend crucially on flow composition. Our approach is to study the…

High Energy Astrophysical Phenomena · Physics 2013-10-02 Rajiv Kumar , Chandra B. Singh , Indranil Chattopadhyay , Sandip K. Chakrabarti