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Related papers: Dynamos of giant planets

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We construct a magnetic helicity conserving dynamo theory which incorporates a calculated magnetic helicity current. In this model the fluid helicity plays a small role in large scale magnetic field generation. Instead, the dynamo process…

Astrophysics · Physics 2009-10-31 Ethan T. Vishniac , Jungyeon Cho

The mechanism by which the Earth's magnetic field is generated is thought to be thermal convection in the metallic liquid iron core. Computational considerations previously restricted most numerical simulations to a regime where the…

Geophysics · Physics 2017-01-17 Andrey Sheyko , Christopher Finlay , Jean Favre , Andrew Jackson

We study the cosmic evolution of the magnetic fields of a large sample of spiral galaxies in a cosmologically representative volume by employing a semi-analytic galaxy formation model and numerical dynamo solver in tandem. We start by…

Astrophysics of Galaxies · Physics 2019-01-03 Luiz Felippe S. Rodrigues , Luke Chamandy , Anvar Shukurov , Carlton M. Baugh , A. Russ Taylor

Context: Convectively-driven flows play a crucial role in the dynamo processes that are responsible for producing magnetic activity in stars and planets. It is still not fully understood why many astrophysical magnetic fields have a…

Solar and Stellar Astrophysics · Physics 2018-05-09 P. J. Bushby , P. J. Käpylä , Y. Masada , A. Brandenburg , B. Favier , C. Guervilly , M. J. Käpylä

The operation of the solar global dynamo appears to involve many dynamical elements. Self-consistent MHD simulations which realistically incorporate all of these processes are not yet computationally feasible, though some elements can now…

Astrophysics · Physics 2008-11-26 Allan Sacha Brun , Mark S. Miesch , Juri Toomre

A framework is introduced for coupling the evolution of galactic magnetic fields sustained by the mean-field dynamo with the formation and evolution of galaxies in cold dark matter cosmology. Estimates of the steady-state strength of the…

Astrophysics of Galaxies · Physics 2015-05-20 Luiz Felippe S. Rodrigues , Anvar Shukurov , Andrew Fletcher , Carlton Baugh

We review our current understanding of galactic dynamo theory, paying particular attention to numerical simulations both of the mean-field equations and the original three-dimensional equations relevant to describing the magnetic field…

Astrophysics of Galaxies · Physics 2014-12-12 Axel Brandenburg

The numerical simulations of planetary dynamos still operate in a regime very far from the planets. For example, it seems unlikely that viscous forces are at all significant in planetary interiors, yet some of the simulations display a…

Earth and Planetary Astrophysics · Physics 2015-06-18 P A Davidson

The origin of cosmic magnetism is an issue of fundamental importance in astrophysics. We review here some of the ideas of how large scale magnetic fields in the universe, particularly in galaxies and galaxy clusters could arise. The popular…

Astrophysics · Physics 2009-06-23 Kandaswamy Subramanian

We propose a new mechanism for turbulent mean-field dynamo in which the magnetic fluctuations resulting from a small-scale dynamo drive the generation of large-scale magnetic fields. This is in stark contrast to the common idea that…

Solar and Stellar Astrophysics · Physics 2015-11-23 Jonathan Squire , Amitava Bhattacharjee

Planets appear to form in environments shaped by the gas flowing through protostellar disks to the central young stars. The flows in turn are governed by orbital angular momentum transfer. In this chapter we summarize current understanding…

Earth and Planetary Astrophysics · Physics 2015-06-18 N. J. Turner , S. Fromang , C. Gammie , H. Klahr , G. Lesur , M. Wardle , X. -N. Bai

Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmosphere. In this paper we use helical…

Solar and Stellar Astrophysics · Physics 2011-09-28 Jörn Warnecke , Axel Brandenburg

The Sun and other cool stars harbouring outer convection zones manifest magnetic activity in their atmospheres. The connection between this activity and the properties of a deep-seated dynamo generating the magnetic flux is not well…

Solar and Stellar Astrophysics · Physics 2015-05-27 Emre Işık , Dieter Schmitt , Manfred Schüssler

Planetary nebulae are thought to be formed when a slow wind from the progenitor giant star is overtaken by a subsequent fast wind generated as the star enters its white dwarf stage$^{1}$. A shock forms near the boundary between the winds,…

Astrophysics · Physics 2015-06-24 Eric G. Blackman , Adam Frank , J. Andrew Markiel , John H. Thomas , Hugh M. Van Horn

A convection-driven MHD dynamo in a rotating spherical shell, with clearly defined structural elements in the flow and magnetic field, is simulated numerically. Such dynamos can be called deterministic, in contrast to those explicitly…

Astrophysics · Physics 2008-11-26 A. V. Getling , R. D. Simitev , F. H. Busse

Magnetic fields can be created in stably stratified (non-convective) layers in a differentially rotating star. A magnetic instability in the toroidal field (wound up by differential rotation) replaces the role of convection in closing the…

Astrophysics · Physics 2009-11-07 H. C. Spruit

Giant planets dominate the mass of many planetary systems, including the Solar System, and represent the best-characterized class of extrasolar planets. Understanding the formation of giant planets bridges the high mass end of the planet…

Earth and Planetary Astrophysics · Physics 2025-01-24 Andrew N. Youdin , Zhaohuan Zhu

Planet-planet scattering best explains the eccentricity distribution of extrasolar giant planets. Past literature showed that the orbits of planets evolve due to planet-planet scattering. This work studies the spin evolution of planets in…

Earth and Planetary Astrophysics · Physics 2021-11-03 Yu-Cian Hong , Dong Lai , Jonathan I. Lunine , Philip D. Nicholson

We propose a new self-consistent dynamo mechanism for the generation of large-scale magnetic fields in natural objects. Recent computational studies have described the formation of large-scale vortices (LSVs) in rotating turbulent…

Fluid Dynamics · Physics 2015-06-24 Celine Guervilly , David W. Hughes , Chris A. Jones

We consider the generation of magnetic field by the flow of a fluid for which the electrical conductivity is nonuniform. A new amplification mechanism is found which leads to dynamo action for flows much simpler than those considered so…

Fluid Dynamics · Physics 2016-05-04 Francois Petrelis , Alexandros Alexakis , Christophe Gissinger