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Related papers: Anelastic spherical dynamos with radially variable…

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We report the finding of an azimuthal dynamo wave of a low-order (m=1) mode in direct numerical simulations (DNS) of turbulent convection in spherical shells. Such waves are predicted by mean field dynamo theory and have been obtained…

Solar and Stellar Astrophysics · Physics 2013-12-19 Elizabeth Cole , Petri J. Käpylä , Maarit J. Mantere , Axel Brandenburg

In a previous paper, we have reported numerical simulations of the MHD flow driven by a travelling magnetic field (TMF) in an annular channel, at low Reynolds number. It was shown that the stalling of such induction pump is strongly related…

Fluid Dynamics · Physics 2016-03-23 Paola Rodriguez Imazio , Christophe Gissinger

It is usually believed that the geo-dynamo of the Earth or more generally of other planets, is created by the convective fluid motions inside their molten cores. An alternative to this thermal or compositional convection can however be…

Fluid Dynamics · Physics 2016-08-16 P. Le Gal , L. Lacaze , S. Le Dizès

The aim of this article is to study how the differential rotation of solar-like stars is influenced by rotation rate and mass in presence of magnetic fields generated by a convective dynamo. We use the ASH code to model the convective…

Solar and Stellar Astrophysics · Physics 2016-09-21 J. Varela , A. Strugarek , A. S. Brun

We present simulations of isolated disc galaxies in a realistic environment performed with the Tree-SPMHD-Code Gadget-3. Our simulations include a spherical circum-galactic medium (CGM) surrounding the galactic disc, motivated by…

Astrophysics of Galaxies · Physics 2018-11-28 Ulrich P. Steinwandel , Marcus C. Beck , Alexander Arth , Klaus Dolag , Benjamin P. Moster , Peter Nielaba

Solar differential rotation exhibits a prominent feature: its cyclic variations over the solar cycle, referred to as zonal flows or torsional oscillations, are observed throughout the convection zone. Given the challenge of measuring…

Solar and Stellar Astrophysics · Physics 2024-02-27 Krishnendu Mandal , Alexander G. Kosovichev , Valery V. Pipin

In weakly collisional extragalactic plasmas such as the intracluster medium, viscous stress and the rate of change of the magnetic-field strength are proportional to the local pressure anisotropy, so subject to constraints imposed by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Federico Mogavero , Alexander A. Schekochihin

Stellar winds are an integral part of the underlying dynamo, the motor of stellar activity. The wind controls the star's angular momentum loss, which depends on the magnetic field geometry which varies significantly in time and latitude.…

Solar and Stellar Astrophysics · Physics 2021-03-16 P. Jakab , A. Brandenburg

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

This is a brief review of the main results of our recent studies of the nonlinear evolution of the small-scale MHD dynamo in the high-Prandtl-number regime and of the structure of the resulting saturated state of the isotropic homogeneous…

Astrophysics · Physics 2007-05-23 A. A. Schekochihin , S. C. Cowley , G. W. Hammett , J. L. Maron , J. C. McWilliams

We present two-dimensional, cylindrically symmetric simulations of hydrodynamic and magnetohydrodynamic (MHD) wide-angle winds interacting with a collapsing environment. These simulations have direct relevance to young stellar objects…

Astrophysics · Physics 2009-11-07 T. A. Gardiner , A. Frank , L. Hartmann

Magnetic fields of low-mass stars and planets are thought to originate from self-excited dynamo action in their convective interiors. Observations reveal a variety of field topologies ranging from large-scale, axial dipole to more…

Solar and Stellar Astrophysics · Physics 2015-06-04 Martin Schrinner , Ludovic Petitdemange , Emmanuel Dormy

Recent spectropolarimetric surveys of main-sequence intermediate-mass stars have exhibited a dichotomy in the distribution of the observed magnetic field between the kG dipoles of Ap/Bp stars and the sub-Gauss magnetism of Vega and Sirius.…

Solar and Stellar Astrophysics · Physics 2015-08-12 Mathieu Gaurat , Laurène Jouve , François Lignières , Thomas Gastine

We study how stably stratified or semi-convective layers alter tidal dissipation rates associated with the generation of inertial, gravito-inertial, interfacial and surface gravity waves in rotating giant planets. We explore scenarios in…

Earth and Planetary Astrophysics · Physics 2023-11-07 Christina M. Pontin , Adrian J. Barker , Rainer Hollerbach

The inverse cascade of magnetic energy occurs when helicity or rotational instability exists in the magnetohydrodynamic (MHD) system. This well known phenomenon has been considered as a basis for the large scale magnetic field in universe.…

Plasma Physics · Physics 2016-02-16 Kiwan Park

To ascertain whether magnetic dynamos operate in rocky exoplanets more massive or hotter than the Earth, we developed a parametric model of a differentiated rocky planet and its thermal evolution. Our model reproduces the established…

Earth and Planetary Astrophysics · Physics 2015-05-19 Eric Gaidos , Clinton P. Conrad , Michael Manga , John Hernlund

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several…

Astrophysics · Physics 2011-02-11 Matthew Browning , Mark S. Miesch , Allan Sacha Brun , Juri Toomre

The dynamo action achieved in the convective cores of main-sequence massive stars is explored here through 3D global simulations of convective core dynamos operating within a young $\Msun{10}$ B-type star, using the anelastic spherical…

Solar and Stellar Astrophysics · Physics 2016-10-05 Kyle C. Augustson , Allan Sacha Brun , Juri Toomre

The dynamics of stably stratified stellar radiative zones is of considerable interest due to the availability of increasingly detailed observations of Solar and stellar interiors. This article reports the first non-axisymmetric and…

Fluid Dynamics · Physics 2021-05-13 Radostin D. Simitev , Friedrich H. Busse

The question of the origin and evolution of magnetic fields in stars possessing a radiative envelope, like the A-type stars, is still regarded as a challenge for stellar physics. Those zones are likely to be differentially rotating, which…

Solar and Stellar Astrophysics · Physics 2015-06-23 Laurène Jouve , Thomas Gastine , François Lignières