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Related papers: Convective Dynamo Simulation with a Grand Minimum

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We carry out non-rotating high-resolution calculations of the solar global convection, which resolve convective scales of less than 10 Mm. To cope with the low Mach number conditions in the lower convection zone, we use the reduced speed of…

Solar and Stellar Astrophysics · Physics 2015-06-18 H. Hotta , M. Rempel , T. Yokoyama

Self-sustained convective dynamos in planetary systems operate in an asymptotic regime of rapid rotation, where a balance is thought to hold between the Coriolis, pressure, buoyancy and Lorentz forces (the MAC balance). Classical numerical…

Geophysics · Physics 2018-03-30 Julien Aubert , Thomas Gastine , Alexandre Fournier

Context. Multidimensional hydrodynamic simulations of convection in stellar interiors are numerically challenging, especially for flows at low Mach numbers. Methods. We explore the benefits of using a low-Mach hydrodynamic flux solver and…

Solar and Stellar Astrophysics · Physics 2021-09-08 L. Horst , R. Hirschi , P. V. F. Edelmann , R. Andrassy , F. K. Roepke

We seek to understand the transition from nearly axisymmetric configurations at solar rotation rates to nonaxisymmetric configurations for rapid rotation using 3D numerical simulations of turbulent convection and considering rotation rates…

To study properties of magneto-hydrodynamic (MHD) convection and resultant dynamo activities in proto-neutron stars (PNSs), we construct a "PNS in a box" simulation model with solving compressible MHD equation coupled with a nuclear…

High Energy Astrophysical Phenomena · Physics 2022-02-21 Youhei Masada , Tomoya Takiwaki , Kei Kotake

We have developed 3D, compressible, non-linear radiative MHD simulations to study the influence of the magnetic field of various strength and geometry on the turbulent convective cells and on the excitation mechanisms of the acoustic…

Solar and Stellar Astrophysics · Physics 2009-01-29 Irina Kitiashvili , Laetitia Jacoutot , Alexander Kosovichev , Alan Wray , Nagi Mansour

We use three-dimensional direct numerical simulations of the helically forced magnetohydrodynamic equations in spherical shell segments in order to study the effects of changes in the geometrical shape and size of the domain on the growth…

Astrophysics · Physics 2010-01-15 Dhrubaditya Mitra , Reza Tavakol , Axel Brandenburg , David Moss

We report the results of three-dimensional numerical simulations of convection-driven dynamos in relatively thin rotating spherical shells that show a transition from an strong non-oscillatory dipolar magnetic field to a weaker regularly…

Fluid Dynamics · Physics 2011-02-08 R. D. Simitev , F. H. Busse , A. G. Kosovichev

Rapidly rotating late M dwarfs are observed in two different branches of magnetic activity, although they operate in the same stellar parameter range. Current empirical evidence indicates that M dwarfs with spectral types ranging from M3 /…

Solar and Stellar Astrophysics · Physics 2025-11-18 Giuseppina Nigro , Francesco Berrilli , Giuseppe Bono , Dario Del Moro , Luca Giovannelli , Valentina Penza , Raffaele Reda

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the…

Solar and Stellar Astrophysics · Physics 2016-05-17 Joyce A. Guzik , T. H. Morgan , N. J. Nelson , C. Lovekin , K. Kosak , I. N. Kitiashvili , N. N. Mansour , A. Kosovichev

In this article we review small-scale dynamo processes that are responsible for magnetic field generation on scales comparable to and smaller than the energy carrying scales of turbulence. We provide a review of critical observation of…

Solar and Stellar Astrophysics · Physics 2023-07-19 Matthias Rempel , Tanayveer Bhatia , Luis Bellot Rubio , Maarit J. Korpi-Lagg

The Sun has a steady 11-year cycle in magnetic activity most well-known by the rising and falling in the occurrence of dark sunspots on the solar disk in visible bandpasses. The 11-year cycle is also manifest in the variations of emission…

Solar and Stellar Astrophysics · Physics 2016-09-19 Ricky Egeland , Willie Soon , Sallie Baliunas , Jeffrey C. Hall , Alexei A. Pevtsov , Gregory W. Henry

Observations of chromospheric and coronal emissions from various solar-type stars show that the stellar magnetic activity varies with the rotation rates of the stars. The faster the star rotates, its magnetic activity gets stronger but…

Solar and Stellar Astrophysics · Physics 2019-10-16 Gopal Hazra , Jie Jiang , Bidya Binay Karak , Leonid Kitchatinov

The existence of large-scale dynamos in rigidly rotating turbulent convection without shear is studied using three-dimensional numerical simulations of penetrative rotating compressible convection. We demonstrate that rotating convection in…

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

We present preliminary results of a 3D MHD simulation of the convective envelope of the giant star Pollux for which the rotation period and the magnetic field intensity have been measured from spectroscopic and spectropolarimetric…

Solar and Stellar Astrophysics · Physics 2016-11-25 A. Palacios , A. S. Brun

Continued progress in observational stellar astrophysics requires a deep understanding of the underlying convection dynamics. We present results of realistic 3D radiative hydrodynamic simulations of the outer layers of a moderate mass star…

Solar and Stellar Astrophysics · Physics 2016-04-27 Irina N. Kitiashvili , Alexander G. Kosovichev , Nagi N. Mansour , Alan A. Wray

Detection of solar gravity modes remains a major challenge to our understanding of the innerparts of the Sun. Their frequencies would enable the derivation of constraints on the core physical properties while their amplitudes can put severe…

Astrophysics · Physics 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

We report on simulations of turbulent, rotating, stratified, magnetohydrodynamic convection in spherical wedge geometry. An initially small-scale, random, weak-amplitude magnetic field is amplified by several orders of magnitude in the…

Solar and Stellar Astrophysics · Physics 2013-11-19 Petri J. Käpylä , Maarit J. Mantere , Axel Brandenburg

The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear…

Astrophysics · Physics 2008-05-27 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

Over the last decades, realistic 3D radiative-MHD simulations have become the dominant theoretical tool for understanding the complex interactions between the plasma and the magnetic field on the Sun. Most of such simulations are based on…

Solar and Stellar Astrophysics · Physics 2018-10-17 E. Khomenko , N. Vitas , M. Collados , A. de Vicente