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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

We investigate the action of the magnetorotational instability (MRI) in the context of iron-core collapse. Exponential growth of the field on the rotation time scale by the MRI will dominate the linear growth process of field line…

Astrophysics · Physics 2009-11-07 Shizuka Akiyama , J. Craig Wheeler , David L. Meier , Itamar Lichtenstadt

We carried out 2D-axisymmetric MHD simulations of core-collapse supernovae for rapidly-rotating magnetized progenitors. By changing both the strength of the magnetic field and the spatial resolution, the evolution of the magnetorotational…

High Energy Astrophysical Phenomena · Physics 2016-02-03 Hidetomo Sawai , Shoichi Yamada

Bearing in mind the application to core-collapse supernovae, we study nonlinear properties of the magneto-rotational instability (MRI) by means of three- dimensional simulations in the framework of a local shearing box approximation. By…

Solar and Stellar Astrophysics · Physics 2015-06-11 Y. Masada , T. Takiwaki , K. Kotake , T. Sano

The magnetorotational instability (MRI) can be a powerful mechanism amplifying the magnetic field in core-collapse supernovae. Whether initially weak magnetic fields can be amplified by this instability to dynamically relevant strengths is…

Solar and Stellar Astrophysics · Physics 2016-03-03 Tomasz Rembiasz , Martin Obergaulinger , Pablo Cerdá-Durán , Ewald Müller , Miguel-Ángel Aloy

Magnetorotational instability (MRI) has been suggested to lead a rapid growth of the magnetic field in core collapse supernovae and produce departures from spherical syymmetry that can be important in determining the explosion mechanism. We…

Solar and Stellar Astrophysics · Physics 2015-05-14 V. Urpin

Global three dimensional magnetohydrodynamic (MHD) simulations of turbulent accretion disks are presented which start from fully equilibrium initial conditions in which the magnetic forces are accounted for and the induction equation is…

High Energy Astrophysical Phenomena · Physics 2015-06-12 E. R. Parkin , G. V. Bicknell

We study the influence of numerical methods and grid resolution on the termination of the magnetorotational instability (MRI) by means of parasitic instabilities in three-dimensional shearing-disc simulations reproducing typical conditions…

Solar and Stellar Astrophysics · Physics 2016-06-22 T. Rembiasz , M. Obergaulinger , P. Cerdá-Durán , M. Á. Aloy , E. Müller

The magnetorotational instability (MRI) is key physics in accretion disks and is widely considered to play some role in massive-star core collapse. Models of rotating massive stars naturally develop very strong shear at composition…

Solar and Stellar Astrophysics · Physics 2015-06-23 J. Craig Wheeler , Daniel Kagan , Emmanouil Chatzopoulos

Whether the magnetorotational instability (MRI) can amplify initially weak magnetic fields to dynamically relevant strengths in core collapse supernovae is still a matter of active scientific debate. Recent numerical studies have shown that…

Solar and Stellar Astrophysics · Physics 2016-06-03 Tomasz Rembiasz , Jérôme Guilet , Martin Obergaulinger , Pablo Cerdá-Durán , Miguel-Ángel Aloy , Ewald Müller

We performed 2D, axisymmetric, MHD simulations with Cosmos++ in order to examine the growth of the magnetorotational instability (MRI) in core--collapse supernovae. We have initialized a non--rotating 15 solar mass progenitor, infused with…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Shizuka Akiyama , Jay D. Salmonson

We discuss the relevance of the magnetorotational instability (MRI) in core-collapse supernovae (CCSNe). Our recent numerical studies show that in CCSNe, the MRI is terminated by parasitic instabilities of the Kelvin-Helmholtz type. To…

High Energy Astrophysical Phenomena · Physics 2017-07-05 Tomasz Rembiasz , Martin Obergaulinger , Jérôme Guilet , Pablo Cerdá-Durán , Miguel-Ángel Aloy , E. Müller

We performed the first numerical simulations of magnetorotational instability from a sub-magnetar-class seed magnetic field in core collapse supernovae. As a result of axisymmetric ideal MHD simulations, we found that the magnetic field is…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Hidetomo Sawai , Shoichi Yamada , Hideyuki Suzuki

The magnetorotational instability (MRI) is the leading candidate for driving turbulence, angular momentum transport, and accretion in astrophysical disks. I consider the linear theory of the MRI in a thin, equatorial disk in the Kerr…

Astrophysics · Physics 2009-11-10 Charles F. Gammie

We present the results obtained from linear stability analysis and 2.5-dimensional magnetohydrodynamic (MHD) simulations of the magnetorotational instability (MRI), including the effects of cosmic rays (CRs). We took into account of the CR…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Takuhito Kuwabara , Chung-Ming Ko

We investigated the impacts of magnetorotational instability (MRI) on the dynamics of weakly magnetized, rapidly rotating core-collapse by conducting high resolution MHD simulations in axisymmetry with simplified neutrino transfer. We found…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Hidetomo Sawai , Shoichi Yamada

We use a global magnetohydrodynamic simulation of a geometrically thin accretion disk to investigate the locality and detailed structure of turbulence driven by the magnetorotational instability (MRI). The model disk has an aspect ratio $H…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Kris Beckwith , Philip J. Armitage , Jacob B. Simon

We examine the properties of strongly magnetized accretion discs in a global framework, with particular focus on the evolution of magnetohydrodynamic instabilities such as the magnetorotational instability (MRI). Work by Pessah and Psaltis…

High Energy Astrophysical Phenomena · Physics 2017-11-13 Upasana Das , Mitchell C. Begelman , Geoffroy Lesur

We study the magnetorotational instability (MRI) using nonmodal stability techniques. Despite the spectral instability of many forms of the MRI, this proves to be a natural method of analysis that is well-suited to deal with the…

High Energy Astrophysical Phenomena · Physics 2014-12-01 Jonathan Squire , Amitava Bhattacharjee

Magnetorotational instability (MRI) in a convectively-stable layer around the neutrinosphere is simulated by a three-dimensional model of supernova core. To resolve MRI-unstable modes, a thin layer approximation considering only the radial…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Youhei Masada , Tomoya Takiwaki , Kei Kotake
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