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Related papers: Magnetohydrodynamic experiments on cosmic magnetic…

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We conduct global galactic--scale magnetohydrodynamical (MHD) simulations of the cosmic--ray driven dynamo. We assume that exploding stars deposit small--scale, randomly oriented, dipolar magnetic fields into the differentially rotating…

Astrophysics of Galaxies · Physics 2009-11-13 Michał Hanasz , Dominik Wóltański , Kacper Kowalik , Rafał Pawłaszek

We carried out global three-dimensional magneto-hydrodynamic simulations of dynamo activities in galactic gaseous disks without assuming equatorial symmetry. Numerical results indicate the growth of azimuthal magnetic fields non-symmetric…

Astrophysics of Galaxies · Physics 2015-06-12 Mami Machida , Kenji E. Nakamura , Takahiro Kudoh , Takuya Akahori , Sofue Yoshiaki , Ryoji Matsumoto

The magnetohydrodynamic dynamo effect explains the generation of self-sustained magnetic fields in electrically conducting flows, especially in geo- and astrophysical environments. Yet the details of this mechanism are still unknown, e.g.,…

Fluid Dynamics · Physics 2015-06-16 Angelo Limone , David R Hatch , Cary B Forest , Frank Jenko

Many astrophysical disks, such as protoplanetary disks, are in a regime where non-ideal, plasma-specific magnetohydrodynamic (MHD) effects can significantly influence the behavior of the magnetorotational instability (MRI). The possibility…

Plasma Physics · Physics 2015-06-24 K. Flanagan , M. Clark , C. Collins , C. M. Cooper , I. V. Khalzov , J. Wallace , C. B. Forest

The effect of cosmic rays on the Parker-Jeans instability in magnetized self-gravitating gaseous disks is studied by three-dimensional magnetohydrodynamic (MHD) simulations with cosmic rays taken as a massless fluid with notable pressure.…

High Energy Astrophysical Phenomena · Physics 2020-08-26 Takuhito Kuwabara , Chung Ming Ko

Angular momentum transport in accretion disk has been the focus of intense research in theoretical astrophysics for many decades. In the past twenty years, MHD turbulence driven by the magnetorotational instability has emerged as an…

Solar and Stellar Astrophysics · Physics 2015-06-15 Sebastien Fromang

The process of diffusive shock acceleration relies on the efficacy with which hydromagnetic waves can scatter charged particles in the precursor of a shock. The growth of self-generated waves is driven by both resonant and non-resonant…

Astrophysics · Physics 2009-11-13 B. Reville , S. O'Sullivan , P. Duffy , J. G. Kirk

The project A2 of the LIMTECH Alliance aimed at a better understanding of those magnetohydrodynamic instabilities that are relevant for the generation and the action of cosmic magnetic fields. These comprise the hydromagnetic dynamo effect…

Using magnetohydrodynamic (MHD) adaptive mesh refinement simulations, we study the formation and early evolution of disk galaxies with a magnetized interstellar medium. For a $10^{10}$ \msun halo with initial NFW dark matter and gas…

Astrophysics · Physics 2009-04-17 Peng Wang , Tom Abel

The influence of the presence of cosmic fluid on the magnetosonic waves and modulation instabilities in the interstellar medium of spiral galaxies is investigated. The fluid model is developed by modifying the pressure equation in such…

Plasma Physics · Physics 2025-01-08 Jyoti Turi , Gadadhar Banerjee

The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense…

High Energy Astrophysical Phenomena · Physics 2017-04-19 Anvar Shukurov , Andrew Snodin , Amit Seta , Paul Bushby , Toby Wood

The magnetorotational instability (MRI) has been suggested to have an important role on the dynamics of accretion disks. We investigate MRI as an alternative way for guiding the plasma from the disk to the funnel flow at the…

High Energy Astrophysical Phenomena · Physics 2012-10-08 S. Dogan , E. R. Pekunlu

We report the first experimental observation of reversals of a dynamo field generated in a laboratory experiment based on a turbulent flow of liquid sodium. The magnetic field randomly switches between two symmetric solutions B and -B. We…

We perform the first magnetohydrodynamic simulations in full general relativity of self-consistent rotating neutron stars (NSs) with ultrastrong mixed poloidal and toroidal magnetic fields. The initial uniformly rotating NS models are…

General Relativity and Quantum Cosmology · Physics 2022-02-23 Antonios Tsokaros , Milton Ruiz , Stuart L. Shapiro , Kōji Uryū

Efficient acceleration of cosmic rays (via the mechanism of diffusive shock acceleration) requires turbulent, amplified magnetic fields in the shock's upstream region. We present results of multidimensional particle-in-cell simulations…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Thomas Stroman , Martin Pohl , Jacek Niemiec

Magnetic fields are an important component of the interstellar medium (ISM) and exhibit strongly varying field strengths and a non-trivial correlation with the gas density. Its dynamical impact varies between individual regions of the ISM…

Astrophysics of Galaxies · Physics 2021-08-20 Philipp Girichidis

We report first results of first global galactic-scale CR-MHD simulations of cosmic-ray-driven dynamo. We investigate the dynamics of magnetized interstellar medium (ISM), which is dynamically coupled with the cosmic-ray (CR) gas. We assume…

Astrophysics of Galaxies · Physics 2009-11-05 Michał Hanasz , Dominik Wóltański , Kacper Kowalik

Numerical MHD simulations play increasingly important role for understanding mechanisms of stellar magnetism. We present simulations of convection and dynamos in density-stratified rotating spherical fluid shells. We employ a new 3D…

Solar and Stellar Astrophysics · Physics 2015-09-03 Radostin D. Simitev , Alexander G. Kosovichev , Friedrich H. Busse

In preparation for an experimental study of magnetorotational instability (MRI) in liquid metal, we present non-ideal two-dimensional magnetohydrodynamic simulations of the nonlinear evolution of MRI in the experimental geometry. The…

Astrophysics · Physics 2009-11-13 Wei Liu , Jeremy Goodman , Hantao Ji

We investigate the evolution of hydromagnetic perturbations in a small section of accretion disks. It is known that molecular viscosity is negligible in accretion disks. Hence, it has been argued that Magnetorotational Instability (MRI) is…

High Energy Astrophysical Phenomena · Physics 2016-03-02 Sujit K. Nath , Banibrata Mukhopadhyay