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Related papers: Turbulent dynamo in the two-phase interstellar med…

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We conduct two kinds of homogeneous isotropic turbulence simulations relevant for the intracluster medium (ICM): (i) pure turbulence runs without radiative cooling; (ii) turbulent heating$+$radiative cooling runs with global thermal…

Astrophysics of Galaxies · Physics 2019-02-13 Rajsekhar Mohapatra , Prateek Sharma

The injection and evolution of turbulence in the intergalactic medium is studied by means of mesh-based hydrodynamical simulations, including a subgrid scale (SGS) model for small-scale unresolved turbulence. The simulations show that the…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-03 L. Iapichino , W. Schmidt , J. C. Niemeyer , J. Merklein

In dilute astrophysical plasmas, the collisional mean free path of a particle can exceed its Larmor radius. Under these conditions, the thermal conductivity and viscosity of the plasma can be dramatically altered. This alteration allows…

Astrophysics · Physics 2009-11-11 Tanim Islam , Steven Balbus

A local turbulence model is developed to study energy cascades in the interstellar medium (ISM) based on self-consistent two-dimensional fluid simulations. The model describes a partially ionized magnetofluid interstellar medium (ISM) that…

Space Physics · Physics 2015-05-13 Dastgeer Shaikh , Gary P. Zank

The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2-D) hybrid expanding box simulations. We impose an initial ambient magnetic field…

The turbulence driven by gravitational instabilities (GIs) can amplify magnetic fields in massive gaseous disks. This GI dynamo may appear in young circumstellar disks, whose weak ionization challenges other amplification routes, as well as…

Solar and Stellar Astrophysics · Physics 2022-07-27 William Béthune , Henrik Latter

It has recently been shown that a significant slowdown of many stars can be attributed to the emergence of a strong magnetic field within the radiative region, where heat is transferred through radiation in a stably stratified layer. Here,…

Fluid Dynamics · Physics 2023-11-30 Florentin Daniel , Ludovic Petitdemange , Christophe Gissinger

Fluctuation dynamos provide a robust mechanism for amplifying weak seed magnetic fields in turbulent astrophysical plasmas. However, their behaviour in the highly compressible regimes characteristic of the interstellar medium remains…

Astrophysics of Galaxies · Physics 2026-02-18 Ameya Uday Nagdeo , Sharanya Sur , Bhargav Vaidya

We study turbulent dissipation in the ISM and explore some implications for galaxy formation and evolution using 2D MHD numerical simulations of compressible fluids. The turbulent kinetic energy E_k is injected by stellar sources formed…

Astrophysics · Physics 2007-05-23 V. Avila-Reese , E. Vázquez-Semadeni

The maximum magnetic field strength generated by Weibel-type plasma instabilities is estimated for typical conditions in the interstellar medium. The relevant kinetic dispersion relations are evaluated by conducting a parameter study both…

High Energy Astrophysical Phenomena · Physics 2015-06-16 R. C. Tautz , J. Triptow

We consider the scenario of a magnetic field orthogonal to a front separating two media of different temperatures and densities, such as cold and warm interstellar gas, in a 2-D plane-parallel geometry. A linear stability analysis is…

Astrophysics of Galaxies · Physics 2011-02-11 Jennifer M. Stone , Ellen G. Zweibel

The fractal shape and multi-component nature of the interstellar medium together with its vast range of dynamical scales provides one of the great challenges in theoretical and numerical astrophysics. Here we will review recent progress in…

Astrophysics of Galaxies · Physics 2015-05-27 Oliver Gressel , Detlef Elstner , Günther Rüdiger

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

The ordered magnetic field observed via polarized synchrotron emission in nearby disc galaxies can be explained by a mean-field dynamo operating in the diffuse interstellar medium (ISM). Additionally, vertical-flux initial conditions are…

Astrophysics of Galaxies · Physics 2016-01-06 A. Bendre , O. Gressel , D. Elstner

We review recent results from numerical simulations and related models of MHD turbulence in the interstellar medium (ISM) and in molecular clouds. We discuss the implications of turbulence for the processes of cloud formation and evolution,…

Astrophysics · Physics 2007-05-23 E. Vazquez-Semadeni , E. C. Ostriker , T. Passot , C. F. Gammie , J. M. Stone

Galaxies' interstellar media (ISM) are observed to be supersonically-turbulent, but the ultimate power source that drives turbulent motion remains uncertain. The two dominant models are that the turbulence is driven by star formation…

Astrophysics of Galaxies · Physics 2016-03-23 Mark R. Krumholz , Blakesley Burkhart

Dynamo action owing to helically forced turbulence and large-scale shear is studied using direct numerical simulations. The resulting magnetic field displays propagating wave-like behavior. This behavior can be modelled in terms of an…

Astrophysics · Physics 2011-02-11 P. J. Käpylä , A. Brandenburg

We investigate the dynamics of magnetic fields in spiral galaxies by performing 3D MHD simulations of galactic discs subject to a spiral potential. Recent hydrodynamic simulations have demonstrated the formation of inter-arm spurs as well…

Astrophysics · Physics 2009-11-13 C. L. Dobbs , D. J. Price

We present the first study on the amplification of magnetic fields by the turbulent dynamo in the highly subsonic regime, with Mach numbers ranging from $10^{-3}$ to $0.4$. We find that for the lower Mach numbers the saturation efficiency…

High Energy Astrophysical Phenomena · Physics 2021-03-04 Radhika Achikanath Chirakkara , Christoph Federrath , Pranjal Trivedi , Robi Banerjee

Supersonic turbulence is believed to be at the heart of star formation. We have performed smoothed particle magnetohydrodynamics (SPMHD) simulations of the small-scale dynamo amplification of magnetic fields in supersonic turbulence. The…

Instrumentation and Methods for Astrophysics · Physics 2016-06-03 Terrence S. Tricco , Daniel J. Price , Christoph Federrath