English
Related papers

Related papers: The proto--neutron--star dynamo -- viability and i…

200 papers

Convectively driven dynamos with rotation generating magnetic fields on scales large compared with the scale of the turbulent eddies are being reviewed. It is argued that such fields can be understood as the result of an alpha effect.…

Solar and Stellar Astrophysics · Physics 2011-08-19 A. Brandenburg , P. J. Käpylä , M. J. Korpi

The dynamical instability of new-born neutron stars is studied by evolving the linearized hydrodynamical equations. The neutron stars considered in this paper are those produced by the accretion induced collapse of rigidly rotating white…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Yuk Tung Liu

The formation of highly magnetized young neutron stars, called magnetars, is still a strongly debated question. A promising scenario invokes the amplification of the magnetic field by the Tayler-Spruit dynamo in a proto-neutron star (PNS)…

High Energy Astrophysical Phenomena · Physics 2025-03-19 Paul Barrère , Jérôme Guilet , Raphaël Raynaud , Alexis Reboul-Salze

We examine the hypothesis that magnetic fields are inflating the radii of fully convective main sequence stars in detached eclipsing binaries (DEBs). The magnetic Dartmouth stellar evolution code is used to analyze two systems in…

Solar and Stellar Astrophysics · Physics 2015-06-19 Gregory A. Feiden , Brian Chaboyer

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

Direct numerical simulations of incompressible nonhelical randomly forced MHD turbulence are used to demonstrate for the first time that the fluctuation dynamo exists in the limit of large magnetic Reynolds number Rm>>1 and small magnetic…

Although initially thought to be promising for production of the r-process nuclei, standard models of neutrino-heated winds from proto-neutron stars (PNSs) do not reach the requisite neutron-to-seed ratio for production of the lanthanides…

High Energy Astrophysical Phenomena · Physics 2019-11-05 Todd A. Thompson , Asif ud-Doula

1D and 2D supernova simulations for stars between 11 and 25 solar masses are presented, making use of the Prometheus/Vertex neutrino-hydrodynamics code, which employs a full spectral treatment of the neutrino transport. Multi-dimensional…

Astrophysics · Physics 2009-11-11 R. Buras , H. -Th. Janka , M. Rampp , K. Kifonidis

M-dwarf stars are well known for the intense magnetic activity that many of them exhibit. In cool stars with near-surface convection zones, this magnetic activity is thought to be driven largely by the interplay of convection and the large…

Solar and Stellar Astrophysics · Physics 2022-03-30 Connor P. Bice , Juri Toomre

Magnetic fields are expected to play a key role in the dynamics and the ejection mechanisms that accompany the merger of two neutron stars. General relativistic magnetohydrodynamic (MHD) simulations offer a unique opportunity to unravel the…

General Relativity and Quantum Cosmology · Physics 2022-07-27 C. Palenzuela , R. Aguilera-Miret , F. Carrasco , R. Ciolfi , J. V. Kalinani , W. Kastaun , B. Miñano , D. Viganò

The Kelvin-Helmholtz cooling epoch, lasting tens of seconds after the birth of a neutron star in a successful core-collapse supernova, is accompanied by a neutrino-driven wind. For magnetar-strength ($\sim10^{15}$ G) large scale surface…

Astrophysics · Physics 2011-09-29 Todd A. Thompson , Philip Chang , Eliot Quataert

Magnetars are highly magnetized neutron stars that can produce X-ray and soft gamma-ray emissions and that have a dipole of $10^{14}$ G to $10^{15}$ G. A promising mechanism for explaining magnetar formation is magnetic field amplification…

High Energy Astrophysical Phenomena · Physics 2022-09-22 Alexis Reboul-Salze , Jérôme Guilet , Raphaël Raynaud , Matteo Bugli

Spectropolarimetric observations show that many low-mass stars possess large-scale poloidal magnetic fields with considerable dipole component, which in some cases exhibit temporal dynamics - cycles or reversals. Although it is widely…

Solar and Stellar Astrophysics · Physics 2025-07-02 Anna Guseva , Ludovic Petitdemange , Charly Pinçon

We compare the current effects of rotation in stellar evolution to those of the magnetic field created by the Tayler instability. In stellar regions, where magnetic field can be generated by the dynamo due to differential rotation (Spruit…

Astrophysics · Physics 2009-11-10 Andre Maeder , Georges Meynet

The origin and evolution of magnetic fields in the Universe is still an open question. Their observations in galaxies suggest strong magnetic fields already at high redshift as well as at present time. However, neither primordial magnetic…

Astrophysics of Galaxies · Physics 2017-04-21 Michael Rieder , Romain Teyssier

Magnetohydrodynamic (MHD) turbulence is of key importance in many high-energy astrophysical systems, where MHD instabilities can amplify local magnetic field over very short time scales. Specifically, the magnetorotational instability (MRI)…

High Energy Astrophysical Phenomena · Physics 2018-03-30 Philipp Mösta , Christian D. Ott , David Radice , Luke F. Roberts , Erik Schnetter , Roland Haas

Magnetic field is playing an important role at all stages of star evolution from star formation to the endpoints. The main effects are briefly reviewed. We also show that O-type stars have large convective envelopes, where convective dynamo…

Astrophysics · Physics 2009-11-13 André Maeder , Georges Meynet , Cyril Georgy , Sylvia Ekström

The extraordinary energetic activity of magnetars is usually explained in terms of dissipation of a huge internal magnetic field of the order of $10^{15-16}$G. How such a strong magnetic field can originate during the formation of a neutron…

High Energy Astrophysical Phenomena · Physics 2017-07-26 A. G. Pili , N. Bucciantini , L. Del Zanna

Models of core-collapse supernova explosions powered by the neutrino-driven mechanism have matured considerable in recent years. Explosions at the low-mass end of the progenitor spectrum can routinely be simulated in 1D, 2D, and 3D and…

Solar and Stellar Astrophysics · Physics 2016-10-05 B. Müller

For moderate and slow rotation, magnetic activity of solar-like stars is observed to strongly depend on rotation. These observations do not yet have a solid explanation in terms of dynamo theory. We aim to find such an explanation by…

Solar and Stellar Astrophysics · Physics 2020-10-07 J. Warnecke , M. J. Käpylä