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Related papers: Thin discs, thick discs and transition zones

200 papers

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 presence of planets in binary systems poses interesting problems for planet formation theories, both in cases where planets must have formed in very compact discs around the individual stars and where they are located near the edge of…

Earth and Planetary Astrophysics · Physics 2019-09-25 Yayaati Chachan , Richard A. Booth , Amaury H. M. J. Triaud , Cathie Clarke

Protoplanetary "transition" disks have large, mass-depleted central cavities, yet also deliver gas onto their host stars at rates comparable to disks without holes. The paradox of simultaneous transparency and accretion can be explained if…

Solar and Stellar Astrophysics · Physics 2015-06-18 Katherine A. Rosenfeld , Eugene Chiang , Sean M. Andrews

Radiation pressure-dominated accretion disks are predicted to exhibit strong density inhomogeneities on scales much smaller than the disk scale height, due to the nonlinear development of photon bubble instability. Radiation would escape…

Astrophysics · Physics 2009-11-07 Mitchell C. Begelman

We show that accretion disks in several compact X-ray binaries with hydrogen-depleted donors are likely subject to a thermal ionization instability, unless they are strongly irradiated. These disks are particularly interesting in that their…

Astrophysics · Physics 2009-11-07 Kristen Menou , Rosalba Perna , Lars Hernquist

In this work the most spectacular phenomena occurring during the formation of a star are briefly reviewed: accretion through a rotating disc of matter and outflow through the poles of the new stellar object. Magnetic fields have been…

Astrophysics · Physics 2007-05-23 Michele Pestalozzi

Large scale magnetic field threading an accretion disk is a key ingredient in the jet formation model. The most attractive scenario for the origin of such a large scale field is the advection of the field by the gas in the accretion disk…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Xinwu Cao , H. C. Spruit

I present the elements of accretion-disc physics applied to active galactic nuclei. The accretion driving mechanisms are discussed, then models of geometrically-thin discs, both stationary and time-dependent, are addressed. Disc's…

High Energy Astrophysical Phenomena · Physics 2023-03-23 Jean-Pierre Lasota

This work derives the linearized equations of motion, the Lagrangian density, the Hamiltonian density, and the canonical angular momentum density for general perturbations [$\propto \exp(im\phi)$ with $m=0,\pm 1,..$] of a geometrically thin…

Astrophysics · Physics 2009-11-11 L. Zhang , R. V. E. Lovelace

Accretion disks around compact objects are expected to enter an unstable phase at high luminosity. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion…

We study the two-dimensional structure of thin transonic accretion discs in the vicinity of black holes. We use the hydrodynamical version of the Grad-Shafranov equation and focus on the region inside the marginally stable orbit. We show…

Astrophysics · Physics 2009-11-10 V. S. Beskin , A. D. Tchekhovskoy

This is a general review on the observations and physics of black hole X-ray binaries and microquasars, with the emphasize on recent developments in the high energy regime. The focus is put on understanding the accretion flows and measuring…

High Energy Astrophysical Phenomena · Physics 2013-11-04 Shuang-Nan Zhang

X-ray binaries, as bright local sources with short variability timescales for a wide range of accretion processes, represent ideal targets for high-resolution X-ray spectroscopy. In this chapter, we present a high-resolution X-ray spectral…

High Energy Astrophysical Phenomena · Physics 2023-04-13 Joey Neilsen , Nathalie Degenaar

In this paper, we have investigated the accreting millisecond X-ray pulsars, which are rapidly rotating neutron stars in low-mass X-ray binaries. These systems show coherent X-ray pulsations that arise when the accretion flow is…

High Energy Astrophysical Phenomena · Physics 2020-08-18 D. B Zeleke , S. B. Tessema , S. H. Negu

Accretion discs around black holes in X-ray binary stars are warped if the spin axis of the black hole is not perpendicular to the binary orbital plane. They can also become eccentric through an instability involving a resonance with the…

Astrophysics · Physics 2009-11-13 Gordon I. Ogilvie , Barbara T. Ferreira

We perform a set of numerical experiments studying the interaction of Type I X-ray bursts with thin, Shakura-Sunyaev type accretion discs. Careful observations of X-ray spectra during such bursts have hinted at changes occurring in the…

High Energy Astrophysical Phenomena · Physics 2020-01-07 P. Chris Fragile , David R. Ballantyne , Aidan Blankenship

We use hydrodynamic simulations to provide quantitative estimates of the effects of the impact of the accretion stream on disks in interacting binaries. For low accretion rates, efficient radiative cooling of the hotspot region can occur,…

Astrophysics · Physics 2016-08-30 Philip J. Armitage , Mario Livio

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

The X-ray light-curves of the recurring outbursts observed in low-mass X-ray binaries provide strong test beds for constraining (still) poorly understood disc-accretion processes. These light-curves act as a powerful diagnostic to probe the…

High Energy Astrophysical Phenomena · Physics 2018-07-25 B. E. Tetarenko , G. Dubus , J. -P. Lasota , C. O. Heinke , G. R. Sivakoff

We present the results of non linear, hydrodynamic simulations, in three dimensions, of the tidal perturbation of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc mid-plane. The…

Astrophysics · Physics 2015-06-24 J. D. Larwood , R. P. Nelson , J. C. B. Papaloizou , C. Terquem