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Related papers: Spiral-wave-driven accretion in quiescent dwarf no…

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We present three-dimensional Smoothed Particle Hydrodynamics (SPH) simulations investigating the dependence of the accretion rate on the disc thickness around an equal-mass, circular black hole binary system. We find that for thick/hot…

High Energy Astrophysical Phenomena · Physics 2016-05-25 Enrico Ragusa , Giuseppe Lodato , Daniel J. Price

We have performed three-dimensional numerical simulations of accretion discs in a close binary system using the Smoothed Particle Hydrodynamics method. Our result show that, contrary to previous claims, 3D discs do exist even when the…

Astrophysics · Physics 2009-09-25 Hiroshi Yukawa , Henri M. J. Boffin , Takuya Matsuda

According to the standard thin disc theory, it is predicted that the radiation-pressure-dominated inner region of a thin disc is thermally unstable, while observations suggest that it is common for a thin disc of more than 0.01 Eddington…

High Energy Astrophysical Phenomena · Physics 2023-09-25 Yu Zhao , Xiao-Hong Yang , Li Xue , Shuang-Liang Li

We have carried out radiation-hydrodynamic simulations of thermally-driven accretion disc winds in low-mass X-ray binaries. Our main goal is to study the luminosity dependence of these outflows and compare with observations. The simulations…

High Energy Astrophysical Phenomena · Physics 2019-02-13 Nick Higginbottom , Christian Knigge , Knox S. Long , James H. Matthews , Edward J. Parkinson

We present SPH simulations of accretion discs in orbit about rotating compact objects such as black holes and neutron stars, and study the structure of warped discs produced by the Bardeen-Petterson effect. We calculate the transition…

Astrophysics · Physics 2009-10-31 Richard P. Nelson , John C. B. Papaloizou

In this paper we revisit the problem of the tidal interaction occuring between a protostellar accretion disc and a secondary point mass following a parabolic trajectory. We model the disc response analytically and we compare our results…

Astrophysics · Physics 2015-06-24 John D. Larwood

We present a 3D hydrodynamics study of gravitational instabilities (GIs) in a 0.14 M$_{\odot}$ circumbinary protoplanetary disc orbiting a 1 M$_{\odot}$ star and a 0.02 M$_{\odot}$ brown dwarf companion. We examine the thermodynamical state…

Solar and Stellar Astrophysics · Physics 2018-12-31 Karna M. Desai , Thomas Y. Steiman-Cameron , Scott Michael , Kai Cai , Richard H. Durisen

We study a model of weakly ionized, protostellar accretion discs that are threaded by a large-scale, ordered magnetic field and power a centrifugally driven wind. We consider the limiting case where the wind is the main repository of the…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Königl , R. Salmeron , M. Wardle

We use global magnetohydrodynamic simulations to study the influence of net vertical magnetic fields on the structure of geometrically thin ($H/r \approx 0.05$) accretion disks in the Newtonian limit. We consider initial mid-plane gas to…

High Energy Astrophysical Phenomena · Physics 2020-01-23 Bhupendra Mishra , Mitchell C. Begelman , Philip J. Armitage , Jacob B. Simon

We investigate the evolution of angular momentum in SPH simulations of galaxy formation, paying particular attention to artificial numerical effects. We find that a cold gas disc forming in an ambient hot gas halo receives a strong…

Astrophysics · Physics 2009-11-10 T. Okamoto , A. Jenkins , V. R. Eke , V. Quilis , C. S. Frenk

Angular momentum in protostellar discs can be transported either radially, through turbulence induced by the magnetorotational instability (MRI), or vertically, through the torque exerted by a large-scale magnetic field. We present a model…

Astrophysics · Physics 2009-11-13 Raquel Salmeron , Arieh Königl , Mark Wardle

The viscous evolution of a thin disc around a central object is considered. Such discs are described by self-similar solutions in which either all or none of the inflowing mass accretes. An approximate solution for the partial accretion…

High Energy Astrophysical Phenomena · Physics 2012-10-22 K. Yavuz Ekşi

We present the results of hydrodynamical simulations of nonaxisymmetric gas flow past a gravitating compact object in two dimensions. Calculations were performed with uniform flow as well as with transverse velocity and density gradients.…

Astrophysics · Physics 2009-10-28 J. S. Benensohn , D. Q. Lamb , R. E. Taam

In a previous paper, we described new analytic formulae for optically-thick supercritical accretion flows (Watarai 2006, hereafter paper 1). Here we present analytic formulae for optically-thin one-temperature accretion flows including the…

Astrophysics · Physics 2015-06-24 Ken-ya Watarai

We investigate the impact of gas accretion in streams on the evolution of disc galaxies, using magneto-hydrodynamic simulations including advection and anisotropic diffusion of cosmic rays generated by supernovae as the only source of…

Astrophysics of Galaxies · Physics 2021-10-13 Nicolas Peschken , Michał Hanasz , Thorsten Naab , Dominik Wóltański , Artur Gawryszczak

We use local stratified shearing-box simulations to elucidate the impact of two-temperature thermodynamics on the thermal structure of coronae in radiatively efficient accretion flows. Rather than treating the coronal plasma as an…

High Energy Astrophysical Phenomena · Physics 2023-11-01 Christopher J. Bambic , Eliot Quataert , Matthew W. Kunz

We consider the gas dynamics in an accreting binary system of degenerate stars within the framework of the Newtonian approximation. In such a system, the accretion stream can impact the surface of a white dwarf (WD) or neutron star (NS) as…

Solar and Stellar Astrophysics · Physics 2023-05-01 Nikita Kramarev , Andrey Yudin

The coalescence of a compact object with a $10^{4}-10^{7} {\rm M_\odot}$ supermassive black hole (SMBH) produces mHz gravitational waves (GWs) detectable by the future Laser Interferometer Space Antenna (LISA). If such an inspiral occurs in…

High Energy Astrophysical Phenomena · Physics 2019-11-14 A. Derdzinski , D. D'Orazio , P. Duffell , Z. Haiman , A. MacFadyen

Understanding how mass and angular momentum flow through accretion discs remains a fundamental unsolved problem in astrophysics. Accreting white dwarfs offer an ideal laboratory for addressing this question: their variability occurs on…

Warps are suspected in disks around massive compact objects. However, the proposed warping source -- non-axisymmetric radiation pressure -- does not apply to white dwarfs. In this letter we report the first Smoothed Particle Hydrodynamic…

Solar and Stellar Astrophysics · Physics 2012-09-05 M. M. Montgomery