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Related papers: Hot One-Temperature Accretion Flows Revisited

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We calculate the temperature and ionization balance in an outflow from an accreting black hole under illumination by hard radiation from the central object. Electron scattering of the Fe K_alpha photons within the highly ionized expanding…

Astrophysics · Physics 2009-11-10 J. Martin Laming , Lev Titarchuk

Using only the assumption that all interactions between particles in an accretion flow are electromagnetically mediated, it is shown that the time to establish equipartition between ions and electrons is shorter than the characteristic…

Astrophysics · Physics 2007-05-23 James Binney

The Event Horizon Telescope (EHT) collaboration, an Earth-size sub-millimetre radio interferometer, recently captured the first images of the central supermassive black hole in M87. These images were interpreted as gravitationally-lensed…

High Energy Astrophysical Phenomena · Physics 2021-06-30 Yosuke Mizuno , Christian M. Fromm , Ziri Younsi , Oliver Porth , Hector Olivares , Luciano Rezzolla

We have developed an improved model of X-ray emission from optically thin, two-temperature accretion flows, \texttt{kerrflow}, using an exact Monte Carlo treatment of global Comptonization as well as with a fully general relativistic…

High Energy Astrophysical Phenomena · Physics 2022-06-15 Andrzej Niedźwiecki , Michał Szanecki , Andrzej A. Zdziarski , Fu-Guo Xie

We investigate state transitions in black hole X-ray binaries through different parameters by using two-dimensional axisymmetric hydrodynamical simulation method. For radiative cooling in hot accretion flow, we take into account the…

High Energy Astrophysical Phenomena · Physics 2016-04-20 Mao-Chun Wu , Fu-Guo Xie , Ye-Fei Yuan , Zhao-Ming Gan

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

Radiatively inefficient accretion flows (RIAFs) are believed to power supermassive black holes (SMBH) in the underluminous cores of galaxies. Such black holes are typically accompanied by flat-spectrum radio cores indicating the presence of…

High Energy Astrophysical Phenomena · Physics 2014-10-08 Monika Moscibrodzka , Heino Falcke , Hotaka Shiokawa , Charles F. Gammie

We examine a new family of global analytic solutions for optically thick accretion disks, which includes the supercritical accretion regime. We found that the ratio of the advection cooling rate, $Q_{\rm adv}$, to the viscous heating rate,…

Astrophysics · Physics 2016-08-30 K. Watarai

Advection is believed to be the dominant cooling mechanism in optically thin advection-dominated accretion flows (ADAF's). When outflow is considered, however, the first impression is that advection should be of opposite sign in the inflow…

High Energy Astrophysical Phenomena · Physics 2023-01-24 Cheng-Liang Jiao

The radio emission from supermassive black holes in nearby early-type galaxies can be used to test possible explanations for their low luminosities. We calculate the expected contribution from thermal synchrotron emission from hot accretion…

Astrophysics · Physics 2016-08-30 T. Di Matteo , C. L. Carilli , A. C. Fabian

We develop a model for supermassive black hole binaries (SMBHBs) accreting below their Eddington limit, focusing on systems where hot, advection-dominated flows become viable. We specifically explore the spectral appearance of…

High Energy Astrophysical Phenomena · Physics 2025-12-10 Christopher Tiede , Daniel J. D'Orazio

Recent papers discussing advection dominated accretion flows (ADAF) as a solution for astrophysical accretion problems should be treated with some caution because of their uncertain physical basis. The suggestions underlying ADAF involve…

Astrophysics · Physics 2009-10-31 G. S. Bisnovatyi-Kogan , R. V. E. Lovelace

How many fraction of gas available at the outer boundary can finally fall onto the black hole is an important question. It determines the observational appearance of accretion flows, and is also related with the evolution of black hole mass…

High Energy Astrophysical Phenomena · Physics 2010-06-14 Feng Yuan , De-Fu Bu

How many fraction of gas available at the outer boundary can finally fall onto the black hole is an important question. It determines the observational appearance of accretion flows, and is also related with the evolution of black hole mass…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Feng Yuan , Defu Bu

We provide a unified description of thermal equilibria of black hole accretion disks, including the newly-discovered advection-dominated solutions. We classify the solutions on the basis of optical depth and importance of advection cooling.…

Astrophysics · Physics 2009-10-28 Xingming Chen , Marek A. Abramowicz , Jean-Pierre Lasota , Ramesh Narayan , Insu Yi

X-ray continuum spectra of super-Eddington accretion flow are studied by means of Monte Carlo radiative transfer simulations based on the radiation hydrodynamic simulation data, in which both of thermal and bulk Compton scatterings are…

High Energy Astrophysical Phenomena · Physics 2017-12-20 Takaaki Kitaki , Shin Mineshige , Ken Ohsuga , Tomohisa Kawashima

As the luminosity of an accreting black hole drops to a few percent of Eddington, the spectrum switches from the familiar soft state to a hard state that is well-described by a distended and tenuous advection-dominated accretion flow…

Astrophysics · Physics 2009-06-23 Ramesh Narayan , Jeffrey E. McClintock

Hot accretion flows such as advection-dominated accretion flows are generally optically thin in the radial direction. Thus photons generated at some radii can cool or heat electrons at other radii via Compton scattering. Such global Compton…

High Energy Astrophysical Phenomena · Physics 2012-07-16 Fu-Guo Xie , Andrzej Niedzwiecki , Andrzej A. Zdziarski , Feng Yuan

We solve the radiation-hydrodynamic (RHD) equations of supercritical accretion flows in the presence of radiation force and outflow by using self similar solutions. Compare with the pioneer works, in this paper we consider power-law…

High Energy Astrophysical Phenomena · Physics 2016-06-01 Fatemeh Zahra Zeraatgari , Shahram Abbassi , Amin Mosallanezhad

Advection-dominated, high-temperature, quasi-spherical accretion flow onto a compact object, recently considered by a number of authors, assume that the dissipation of turbulent energy of the flow heats the ions and that the dissipated…

Astrophysics · Physics 2009-10-30 G. S. Bisnovatyi-Kogan , R. V. E. Lovelace