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Related papers: Magnetic field generation by the stationary accret…

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We begin an exploration of the capacity of the stationary accretion shock instability (SASI) to generate magnetic fields by adding a weak, stationary, and radial (but bipolar) magnetic field, and in some cases rotation, to an initially…

Astrophysics · Physics 2011-02-11 Eirik Endeve , Christian Y. Cardall , Reuben D. Budiardja , Anthony Mezzacappa

We describe the initial implementation of magnetohydrodynamics (MHD) in our astrophysical simulation code \genasis. Then, we present MHD simulations exploring the capacity of the stationary accretion shock instability (SASI) to generate…

Solar and Stellar Astrophysics · Physics 2015-06-04 E Endeve , C Y Cardall , R D Budiardja , A Mezzacappa

The stationary accretion shock instability (SASI) plays a central role in modern simulations of the explosion phase of core-collapse supernovae (CCSNe). It may be key to realizing neutrino powered explosions, and possibly links birth…

Solar and Stellar Astrophysics · Physics 2015-06-04 E. Endeve , C. Y. Cardall , R. D. Budiardja , A. Mezzacappa , J. M. Blondin

We extend our investigation of magnetic field evolution in three-dimensional flows driven by the stationary accretion shock instability (SASI) with a suite of higher-resolution idealized models of the post-bounce core-collapse supernova…

A stalled spherical accretion shock, such as that arising in core-collapse supernovae, is unstable to non-spherical perturbations. In three dimensions, this Standing Accretion Shock Instability (SASI) can develop spiral modes that spin-up…

Solar and Stellar Astrophysics · Physics 2015-05-18 Rodrigo Fernández

A new magnetic field generation mechanism in electrostatic shocks is found, which can produce fields with magnetic energy density as high as 0.01 of the kinetic energy density of the flows on time scales $ \tilde \, 10^4 \,…

Plasma Physics · Physics 2015-06-22 A. Stockem , T. Grismayer , R. A. Fonseca , L. O. Silva

We present new generation mechanisms of magnetic fields in supernova remnant shocks propagating to partially ionized plasmas in the early universe. Upstream plasmas are dissipated at the collisionless shock, but hydrogen atoms are not…

High Energy Astrophysical Phenomena · Physics 2022-09-08 Shuhei Kashiwamura , Yutaka Ohira

We show that strong magnetic fields can be generated at shock waves associated with formation of galaxies or clusters of galaxies by the Weibel instability, an instability in collisionless plasmas. The estimated strength of the magnetic…

Astrophysics · Physics 2015-06-24 Yutaka Fujita , Tsunehiko N. Kato

Hydrodynamical instabilities, such as the standing accretion-shock instability (SASI), play an essential role in the dynamics of core-collapse supernovae, with observable imprints in the neutrino and gravitational wave signals. Yet, the…

High Energy Astrophysical Phenomena · Physics 2023-03-15 Laurie Walk , Thierry Foglizzo , Irene Tamborra

We propose a model for Diffusive Shock Acceleration (DSA) in which stochastic magnetic fields in the shock precursor are generated through purely fluid mechanisms of a so-called small-scale dynamo. This contrasts with previous DSA models…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Beresnyak , T. W. Jones , A. Lazarian

Context. The influence of magnetic fields on stellar core collapse and explosion is not well explored. It depends on the possibility to amplify the pre-collapse fields. Without rotation this can happen by compression, convection, the…

Solar and Stellar Astrophysics · Physics 2015-03-17 Martin Obergaulinger , Hans-Thomas Janka

By 2D hydrodynamic simulations including a detailed equation of state and neutrino transport, we investigate the interplay between different non-radial hydrodynamic instabilities that play a role during the postbounce accretion phase of…

Astrophysics · Physics 2009-06-23 L. Scheck , H. -Th. Janka , T. Foglizzo , K. Kifonidis

We present the results of numerical experiments, in which we study how the asphericities induced by the growth of the standing accretion shock instability (SASI) produce the gravitational waveforms in the postbounce phase of core-collapse…

Astrophysics · Physics 2016-08-30 Kei Kotake , Naofumi Ohnishi , Shoichi Yamada

During the core collapse of a massive star just before its supernova explosion, the amplification of asymmetric motions by the standing accretion shock instability (SASI) imprints on the neutrino flux and the gravitational waves a frequency…

High Energy Astrophysical Phenomena · Physics 2024-12-18 T. Foglizzo

Our attention focuses on the stochastic dynamo equation with non-normal operator that give an insight into the role of stochastics and non-normality in the galactic magnetic field generation. The main point of this Letter is a discussion of…

Astrophysics · Physics 2009-11-07 Sergei Fedotov

We have studied non-axisymmetric standing accretion shock instability, or SASI, by 3D hydrodynamical simulations. This is an extention of our previous study on axisymmetric SASI. We have prepared a spherically symmetric and steady accretion…

Astrophysics · Physics 2013-08-30 Wakana Iwakami , Kei Kotake , Naofumi Ohnishi , Shoichi Yamada , Keisuke Sawada

In this paper, the generation of magnetic fields in a nonuniformly rotating layer of finite thickness of an electrically conducting fluid by thermomagnetic (TM) instability. This instability arises due to the temperature gradient $\nabla…

Fluid Dynamics · Physics 2021-04-23 M. I. Kopp , K. N. Kulik , A. V. Tur , V. V. Yanovsky

The origin of large-scale and coherent magnetic fields in astrophysical discs is an important and long standing problem. Researchers commonly appeal to a turbulent dynamo, sustained by the magneto-rotational instability (MRI), to supply the…

High Energy Astrophysical Phenomena · Physics 2018-10-24 A. Riols , H. Latter

Two-dimensional axisymmetric simulations have shown that the post-bounce accretion shock in core collapse supernovae is subject to the Spherical Accretion Shock Instability, or SASI. Recent three-dimensional simulations have revealed the…

Astrophysics · Physics 2008-11-26 John M. Blondin , Samantha Shaw

We studied the effects of rotation on standing accretion shock instability (SASI) by performing three-dimensional hydrodynamics simulations. Taking into account a realistic equation of state and neutrino heating/cooling, we prepared a…

Astrophysics · Physics 2009-07-22 Wakana Iwakami , Kei Kotake , Naofumi Ohnishi , Shoichi Yamada , Keisuke Sawada
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