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Related papers: Physics Fundamentals of Luminous Accretion Disks A…

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I provide a broad overview of the basic theoretical paradigms of black hole accretion flows. Models that make contact with observations continue to be mostly based on the four decade old alpha stress prescription of Shakura & Sunyaev…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Omer Blaes

We discuss the problem of the formation of a large-scale magnetic field in the accretion disks around black holes, taking into account the non-uniform vertical structure of the disk. The high electrical conductivity of the outer layers of…

High Energy Astrophysical Phenomena · Physics 2012-08-07 G. S. Bisnovatyi-Kogan , A. S. Klepnev , R. V. E. Lovelace

Accretion disks are observed in young stars, cataclysmic variables, binary X-ray sources et al. Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was…

Astrophysics · Physics 2007-05-23 G. S. Bisnovatyi-Kogan

We study a truncated accretion disk using a well-resolved, semi-global magnetohydrodynamic simulation that is evolved for many dynamical times (6096 inner disk orbits). The spectral properties of hard state black hole binary systems and…

High Energy Astrophysical Phenomena · Physics 2018-04-25 J. Drew Hogg , Christopher S. Reynolds

Disc spectra from highly luminous black hole binaries are observed to be rather simple, despite theoretical predictions to the contrary. We collate the disc-dominated spectra from multiple observations of 10 separate sources, and show that…

Astrophysics · Physics 2009-11-10 Marek Gierlinski , Chris Done

In this thesis, I study hydrodynamical models of slim accretion disks --- advective, optically thick disks which generalize the standard models of radiatively efficient thin disks to all accretion rates. I start with a general introduction…

High Energy Astrophysical Phenomena · Physics 2011-08-02 A. Sadowski

In this chapter, I present a summary of observational tests of the basic picture of disk accretion. An emphasis is placed on tests relevant to black holes, but many of the fundamental results are drawn from studies of other classes of…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Thomas J. Maccarone

I review our current theoretical understanding of the different possible rotating modes of accretion onto a black hole. I discuss both thick adiabatic flows and radiatively efficient thin disc solutions. I present a new self-consistent…

Astrophysics · Physics 2007-05-23 A. Merloni

Current astrophysical research suggests that the most persistently luminous objects in the Universe are powered by the flow of matter through accretion disks onto black holes. Accretion disk systems are observed to emit copious radiation…

Astrophysics · Physics 2019-04-03 Duane A. Liedahl , Diego F. Torres

We derive all relevant equations needed for constructing a global general relativistic model of advectively cooled, very hot, optically thin accretion disks around black holes and present solutions which describe advection dominated flows…

Astrophysics · Physics 2009-10-28 M. A. Abramowicz , X. -M. Chen , M. Granath , J. -P. Lasota

We show that the removal of angular momentum is possible in the presence of large scale magnetic stresses in geometrically thick, advective, sub-Keplerian accretion flows around black holes in steady-state, in the complete absence of…

High Energy Astrophysical Phenomena · Physics 2015-07-03 Banibrata Mukhopadhyay , Koushik Chatterjee

Stellar-mass black holes offer what is perhaps the best scenario to test theories of gravity in the strong-field regime. In particular, f(R) theories, which have been widely discuss in a cosmological context, can be constrained through…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-13 Daniela Pérez , Gustavo E. Romero , Santiago E. Perez Bergliaffa

This article reviews the physics of advection-dominated accretion flows (ADAFs) and describes applications to several black hole X-ray binaries and galactic nuclei. The possibility of using ADAFs to explore the event horizons of black holes…

Astrophysics · Physics 2007-05-23 Ramesh Narayan , Rohan Mahadevan , Eliot Quataert

There is a very popular two-zone accretion disk model that the inner part of the non-advective Keplerian disk (Shakura-Sunyaev disk) can produce hot advection-dominated accretion flow, which can generate high energy power-law radiation and…

High Energy Astrophysical Phenomena · Physics 2022-10-04 Rajiv Kumar , Ye-Fei Yuan

As described in the review by Marek Abramowicz (these proceedings), accretion theory is at something of a crossroads. Many theoretical descriptions of observations have centered on the ``hydrodynamic'' approach of the ``standard'' Shakura &…

Astrophysics · Physics 2007-05-23 Michael A. Nowak

We present the results of our studies on accretion disks in the proximity of astrophysical black holes. These disks can be of varying degrees of opacity, geometrical shapes, sizes, and volumes. The central compact object is a Schwarzschild…

High Energy Astrophysical Phenomena · Physics 2023-02-27 Leela Elpida Koutsantoniou

In this review, I summarize the main X-ray/hard X-ray properties of the accretion flows around black holes and neutron stars based on recent broad-band spectral and timing observations performed by the BeppoSAX and Rossi X-ray Timing…

Astrophysics · Physics 2009-11-10 Didier Barret

The spectral energy distributions of galactic black holes in the low/hard state and of low-luminosity AGN possess many common features, the most prominent being: compact, flat (or inverted) spectrum radio cores with high brightness…

Astrophysics · Physics 2009-09-17 A. Merloni , A. C. Fabian

Fluid discs and tori around black holes are discussed within different approaches and with the emphasis on the role of disc gravity. First reviewed are the prospects of investigating the gravitational field of a black hole--disc system by…

Astrophysics · Physics 2011-07-19 V. Karas , J. -M. Hure , O. Semerak

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