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Related papers: Evolution of Thin Discs with Partial Accretion

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Decretion (or external) disks are gas disks freely expanding to large radii due to their internal stresses. They are expected to naturally arise in tidal disruption events, around Be stars, in mass-losing post main sequence binaries, as a…

Solar and Stellar Astrophysics · Physics 2016-10-12 Roman R. Rafikov

We use a 3D radiative non-ideal magnetohydrodynamic (MHD) simulation to investigate the formation and evolution of a young protostellar disc from a magnetized pre-stellar core. The simulation covers the first ${\sim}10~{\rm kyr}$ after…

Solar and Stellar Astrophysics · Physics 2021-09-29 Wenrui Xu , Matthew W. Kunz

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

Thin viscous Keplerian accretion disks are considered asymptotically stable, even though they can show significant dynamic activity on short timescales. In this paper the dynamics of non-axisymmetric hydrodynamical disturbances of disks are…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Paola Rebusco , Orkan M. Umurhan , Wlodek Kluzniak , Oded Regev

I solve analytically the viscous evolution of a self-irradiated accretion disc, as seen during outbursts of soft X-ray transients. The solutions predict steep power-law X-ray decays L_X \sim (1+ t/t_visc)^{-4}, changing to L_X \sim…

Astrophysics · Physics 2009-10-30 A. R. King

Using three-dimensional general relativistic magnetohydrodynamic simulations with electron and proton thermodynamics and an electron cooling function, we probe the inner radial and vertical structure of weakly magnetized geometrically thin…

High Energy Astrophysical Phenomena · Physics 2025-08-28 A. Hankla , J. Dexter , N. Scepi

We present a non-linear numerical model for a geometrically thin accretion disk with the addition of stochastic non-linear fluctuations in the viscous parameter. These numerical realizations attempt to study the stochastic effects on the…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Philip S. Cowperthwaite , Christopher S. Reynolds

Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud onto the surface of an existing co-rotating disc or from the counter-rotating gas moving radially inward to the outer edge of an existing disc. At the…

Astrophysics of Galaxies · Physics 2015-06-22 Sergei Dyda , Richard V. E. Lovelace , Galina V. Ustyugova , Marina M. Romanova , Alexander V. Koldoba

The evolution of thin axisymmetric viscous accretion disks is a classic problem in astrophysics. While models based on this simplified geometry provide only approximations to the true processes of instability-driven mass and angular…

Instrumentation and Methods for Astrophysics · Physics 2015-02-25 Mark R. Krumholz , John C. Forbes

We study the structure and dynamics of the gap created by a protoplanet in an accretion disc. The hydrodynamic equations for a flat, two-dimensional, non-selfgravitating protostellar accretion disc with an embedded, Jupiter sized…

Astrophysics · Physics 2010-03-01 Willy Kley

A toy model of a disk undergoing steady state accretion onto a black hole is presented. The disk is in a hydrostatic equilibrium for all radii r > r_{in}, with the inner disk radius located between the marginally stable and marginally bound…

Astrophysics · Physics 2007-05-23 Bohdan Paczynski

We aim to examine the detailed disc structure that arises in a misaligned binary system as a function of the disc aspect ratio h, viscosity parameter alpha, disc outer radius R, and binary inclination angle gamma_F. We also aim to examine…

Earth and Planetary Astrophysics · Physics 2015-05-14 Moritz Fragner , Richard Nelson

Warped accretion discs are expected in many protostellar binary systems. In this paper, we study the long-term evolution of disc warp and precession for discs with dimensionless thickness $H/r$ larger than their viscosity parameter…

Earth and Planetary Astrophysics · Physics 2015-06-19 Francois Foucart , Dong Lai

We discuss the properties of an accretion disk around a star with parameters typical of classical T Tauri stars (CTTS), and with the average accretion rate for these disks. The disk is assumed steady and geometrically thin. The turbulent…

Astrophysics · Physics 2011-02-11 Paola D'Alessio , Jorge Canto , Nuria Calvet , Susana Lizano

A self-similar solution for time evolution of isothermal, self-gravitating viscous disks is found under the condition that $\alpha' \equiv \alpha (H/r)$ is constant in space (where $\alpha$ is the viscosity parameter and $H/r$ is the ratio…

Astrophysics · Physics 2009-10-30 Shin Mineshige , Masayuki Umemura

Analytical solution for a thin hydrodynamic accretion disk shows that for some values of the viscosity parameter part of the accretion flow in the disk is not towards the star, but in the opposite direction. We study thin disks by…

Solar and Stellar Astrophysics · Physics 2020-06-09 Ruchi Mishra , Miljenko Čemeljić , Wlodek Kluźniak

Using the anelastic approximation of linearised hydrodynamic equations, we investigate the development of axially symmetric small perturbations in thin Keplerian discs. The sixth-order dispersion equation is derived and numerically solved…

High Energy Astrophysical Phenomena · Physics 2015-07-02 N. Shakura , K. Postnov

Analytical treatment of black hole accretion generally presumes the stability of the stationary configuration. Various authors in the past several decades demonstrated the validity of such an assumption for inviscid hydrodynamic flow.…

High Energy Astrophysical Phenomena · Physics 2014-06-17 Sankhasubhra Nag , Deepika B Ananda , Ishita Maity , Tapas K. Das

The problem of the late accretion phase of the evolution of an axisymmetric, isothermal magnetic disk surrounding a forming star has been formulated in a companion paper. The "central sink approximation" is used to circumvent the problem of…

Astrophysics · Physics 2009-11-10 Konstantinos Tassis , Telemachos Ch. Mouschovias

Two-dimensional accretion flows near black holes have been investigated by time-dependent hydrodynamical calculations. We assume that the flow is axisymmetric and that radiative losses of internal energy are negligible, so that the disc is…

Astrophysics · Physics 2015-06-24 Igor V. Igumenshchev , Xingming Chen , Marek A. Abramowicz