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Related papers: Disk Outflows and the Accretion Rate Gap

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We examine radiative standing shocks in advective accretion flows around stellar-mass black holes by 2D radiation hydrodynamic simulations, focusing on the super-Eddington accreting flow. Under a set of input flow parameters responsible for…

High Energy Astrophysical Phenomena · Physics 2021-02-24 Toru Okuda , Chandra B. Singh

The Bondi accretion rate of black holes in our and nearby galaxies Messier 87, NGC 3115, NGC 1600, and Cygnus A have been determined or constrained using Chandra or other observations. It, however, remains unknown how much mass from the…

Astrophysics of Galaxies · Physics 2023-07-11 Yash Aggarwal

(Abridged) Using an empirical relation between the broad line region size and optical continuum luminosity, we estimated the black hole mass and accretion rate for 135 AGNs with double-peaked broad emission lines in two samples. With black…

Astrophysics · Physics 2009-11-10 Xue-Bing Wu , F. K. Liu

We compute mass outflow rates from advective accretion disks around compact objects, such as neutron stars and black holes. These computations, for the first time, are done using combinations of exact transonic inflow and outflow solutions…

Astrophysics · Physics 2007-05-23 Tapas K. Das , Sandip K. Chakrabarti

The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, $Q=\rho_{\infty}/\sigma^3_{\infty}$, remains constant during the inflow, the derived accretion rate…

Astrophysics · Physics 2008-12-18 Sébastien Peirani , José Antonio De Freitas Pacheco

Recent hydrodynamical simulations of radiatively inefficient black hole accretion flows with low viscosity have demonstrated that these flows differ significantly from those described by an advection-dominated model. The black hole flows…

Astrophysics · Physics 2007-05-23 Marek A. Abramowicz , Igor V. Igumenshchev

Accretion flows around black holes generally result in mass-outflows that exhibit irregular behavior quite often. Using 2D time-dependent hydrodynamical calculations, we show that the mass-outflow is unstable in the cases of thick accretion…

High Energy Astrophysical Phenomena · Physics 2015-08-19 Toru Okuda , Santabrata Das

Active galactic nucleus (AGN) feedback is the process by which supermassive black holes in the centres of galaxies may moderate the growth of their hosts. Gas outflows from supermassive black holes release huge quantities of energy into the…

A solid theoretical understanding of how inflowing, accreting plasma around black holes and other compact objects gives rise to outflowing winds and jets is still lacking, despite decades of observations. The fact that similar processes and…

High Energy Astrophysical Phenomena · Physics 2014-11-20 S. Markoff

Deep observations with the Very Large Array of A0620-00, performed in 2005 August, resulted in the first detection of radio emission from a black hole binary at X-ray luminosities as low as 10^{-8.5} times the Eddington limit. The measured…

Astrophysics · Physics 2009-11-11 E. Gallo , R. Fender , J. Miller-Jones , A. Merloni , P. Jonker , S. Heinz , T. Maccarone , M. van der Klis

More than half of all low-redshift AGN exhibit UV and X-ray absorption by highly ionized gas. The observed UV and X-ray absorption lines are almost always blue-shifted at velocities of hundreds of km/s, indicating that the absorbing gas is…

Astrophysics · Physics 2009-11-10 Gerard A. Kriss

We show how accretion rate governs the physical properties of a sample of unobscured broad-line, narrow-line, and lineless active galactic nuclei (AGNs). We avoid the systematic errors plaguing previous studies of AGN accretion rate by…

We analyze the consequences of the hypothesis that the formation of the Broad Line Region is intrinsically connected with the existence of the cold accretion disk. We assume that the Broad Line Region radius is well estimated by the formula…

Astrophysics · Physics 2009-11-10 B. Czerny , A. Rozanska , J. Kuraszkiewicz

X-ray reflection features observed from the innermost regions of accretion disks in Active Galactic Nuclei (AGNs) allow important tests of accretion theory. In recent years it has been possible to use the Fe K line and reflection continuum…

High Energy Astrophysical Phenomena · Physics 2015-05-27 D. R. Ballantyne , J. R. McDuffie , J. S. Rusin

We study an accretion flow during the gravitational-wave driven evolution of binary massive black holes. After the binary orbit decays due to an interaction with a massive circumbinary disk, the binary is decoupled from the circumbinary…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Kimitake Hayasaki

Recently, the issue of the role of the Eddington limit in accretion discs became a matter of debate. While the classical (spherical) Eddington limit is certainly an over-simplification, it is not really clear how to treat it in a flattened…

Astrophysics · Physics 2015-06-24 D. Heinzeller , W. J. Duschl , S. Mineshige , K. Ohsuga

We discuss two important instability mechanisms that may lead to the limit-cycle oscillations of the luminosity of the accretion disks around compact objects: ionization instability and radiation-pressure instability. Ionization instability…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Agnieszka Janiuk , Bożena Czerny

Accretion flows toward black holes can be of a quite different nature, described as an optically thick cool gas flow in a disk for high accretion rates or as a hot coronal optically thin gas flow for low accretion rates, possibly affected…

High Energy Astrophysical Phenomena · Physics 2017-12-13 E. Meyer-Hofmeister , B. F. Liu , E. Qiao

We perform two-dimensional hydrodynamical simulations of slowly rotating accretion flows in the region of $ 0.01-7\, \mathrm{pc} $ around a supermassive black holes with $ M_\mathrm{BH} = 10^{8} M_{\odot} $. The accretion flow is irradiated…

High Energy Astrophysical Phenomena · Physics 2019-10-23 Amin Mosallanezhad , Feng Yuan , Jeremiah P. Ostriker , Fatemeh Zahra Zeraatgari , De-Fu Bu

Accretion disks around supermassive black holes in active galactic nuclei produce continuum radiation at ultraviolet and optical wavelengths. Physical processes in the accretion flow lead to stochastic variability of this emission on a wide…

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