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Related papers: The Spherical Accretion Shock Instability in the L…

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We study the explosion mechanism of collapse-driven supernovae by numerical simulations with a new nuclear EOS based on unstable nuclei. We report new results of simulations of general relativistic hydrodynamics together with the Boltzmann…

Astrophysics · Physics 2009-11-13 K. Sumiyoshi , S. Yamada , H. Suzuki , H. Shen , H. Toki

We investigate the general stability of 1D spherically symmetric ionized Bondi accretion onto a massive object in the specific context of accretion onto a young stellar object. We first derive a new analytic expression for a steady state…

This paper is a sequel to Takahashi et al. (2016), in which the authors investigated the influences of fluctuations in pre-shock accreting matter on the linear stability of the standing accretion shock in core-collapse supernovae (CCSNe).…

High Energy Astrophysical Phenomena · Physics 2019-04-03 Ken'ichi Sugiura , Kazuya Takahashi , Shoichi Yamada

We consider the evolution in full general relativity of a family of linearly unstable isolated spherical neutron stars under the effects of very small, perturbations as induced by the truncation error. Using a simple ideal-fluid equation of…

General Relativity and Quantum Cosmology · Physics 2011-07-18 David Radice , Luciano Rezzolla , Thorsten Kellermann

When the accretion disc around a weakly magnetised neutron star (NS) meets the stellar surface, it should brake down to match the rotation of the NS, forming a boundary layer. As the mechanisms potentially responsible for this braking are…

High Energy Astrophysical Phenomena · Physics 2020-07-01 Pavel Abolmasov , Joonas Nättilä , Juri Poutanen

We assess the importance of the magneto-rotational instability in core-collapse supernovae by an analysis of the growth rates of unstable modes in typical post-collapse systems and by numerical simulations of simplified models. The…

Solar and Stellar Astrophysics · Physics 2009-11-18 M. Obergaulinger , P. Cerdà-Duràn , E. Müller , M. A. Aloy

The convection that takes place in the innermost shells of massive stars plays an important role in the formation of core-collapse supernova explosions. Upon encountering the supernova shock, additional turbulence is generated, amplifying…

Solar and Stellar Astrophysics · Physics 2020-03-04 Ernazar Abdikamalov , Thierry Foglizzo

(abridged) We study the hydrodynamic evolution of a non-spherical core-collapse supernova in two spatial dimensions. We find that our model displays a strong tendency to expand toward the pole. We demonstrate that this expansion is a…

Solar and Stellar Astrophysics · Physics 2016-11-18 A. Gawryszczak , J. Guzman , T. Plewa , K. Kifonidis

We present an analysis of the linear stability characteristics of shock-containing jets. The flow is linearised around a spatially periodic mean, which acts as a surrogate for a mean flow with a shock-cell structure, leading to a set of…

We study nonlinear stability of spatially homogeneous oscillations in reaction-diffusion systems. Assuming absence of unstable linear modes and linear diffusive behavior for the neutral phase, we prove that spatially localized perturbations…

Analysis of PDEs · Mathematics 2008-07-01 Thierry Gallay , Arnd Scheel

We have examined the stability of a sequence of oblate elliptical galaxy models having the Stackel form suggested by Kuz'min & Kutuzov. We have employed the 2-integral DFs given by Dejonghe & de Zeeuw for which flattened non-rotating models…

Astrophysics · Physics 2015-06-24 J. A. Sellwood , M. Valluri

Nonspherical mass motions are a generic feature of core-collapse supernovae, and hydrodynamic instabilities play a crucial role for the explosion mechanism. First successful neutrino-driven explosions could be obtained with self-consistent,…

Solar and Stellar Astrophysics · Physics 2016-11-23 H. -Thomas Janka , Tobias Melson , Alexander Summa

Analytical studies and numerical simulations of time dependent axially symmetric flows onto black holes have shown that it is possible to produce stationary shock waves with a stable position both for ideal inviscid and for moderately…

Astrophysics · Physics 2019-08-17 Diego Molteni , Gabor Toth , Oleg A. Kuznetsov

This paper presents a theoretical study of oscillatory and rotational instabilities of a solid spherical body, levitated electromagnetically in axisymmetric coils made of coaxial circular loops. We apply our previous theory to analyze the…

Classical Physics · Physics 2007-05-23 J. Priede , G. Gerbeth

High-resolution simulations of the cooling regions of spherically symmetric supernova remnants demonstrate a strong radiative instability. This instability, whose presence is dependent on the shock velocity, causes large-amplitude…

Astrophysics · Physics 2009-10-30 Paul A. Kimoto , David F. Chernoff

Neutrino-driven convection plays a crucial role in the development of core-collapse supernova (CCSN) explosions. However, the complex mechanism that triggers the shock revival and the subsequent explosion has remained inscrutable for many…

Solar and Stellar Astrophysics · Physics 2020-06-24 Jordi Casanova , Eirik Endeve , Eric J. Lentz , O. E. Bronson Messer , W. Raphael Hix , J. Austin Harris , Stephen W. Bruenn

The process of uniform supernovae explosions (SNe) is well investigated for all their types. However, observational data suggests that the SNe could be not spherically-symmetric. Modern multi-dimensional simulations of SNe demonstrate…

High Energy Astrophysical Phenomena · Physics 2022-02-16 I. Kalashnikov , A. Baranov , P. Chardonnet , V. Chechetkin , A. Filina

This paper is a sequel to our previous work for accretion onto a Schwarzschild black hole and the so-called standing accretion shock instability (SASI), in this paper we investigate non-axisymmetric perturbations for a Kerr black hole. The…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Hiroki Nagakura , Shoichi Yamada

Supernovae explosions of massive stars are nowadays believed to result from a two-step process, with an initial gravitational core collapse followed by an expansion of matter after a bouncing on the core. This scenario meets several…

Solar and Stellar Astrophysics · Physics 2022-08-02 Pierre-Henri Chavanis , Bruno Denet , Martine Le Berre , Yves Pomeau

We study linear and nonlinear stability of asymptotically AdS$_4$ solutions in Einstein-Maxwell-scalar theory. After summarizing the set of static solutions we first examine thermodynamical stability in the grand canonical ensemble and the…

High Energy Physics - Theory · Physics 2017-05-24 Raúl Arias , Javier Mas , Alexandre Serantes