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Related papers: Magnetar formation through a convective dynamo in …

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Magnetohydrodynamic simulations of fully convective, rotating spheres with volume heating near the center and cooling at the surface are presented. The dynamo-generated magnetic field saturates at equipartition field strength near the…

Astrophysics · Physics 2007-05-23 W. Dobler , M. Stix , A. Brandenburg

We consider a newly-born millisecond magnetar, focusing on its interaction with the dense stellar plasma in which it is initially embedded. We argue that the confining pressure and inertia of the surrounding plasma acts to collimate the…

Astrophysics · Physics 2009-11-11 Dmitri A. Uzdensky , Andrew I. MacFadyen

In this paper, we present the results of 3-dimensional collapse simulations of rotating stars for a range of stellar progenitors. We find that for the fastest spinning stars, rotation does indeed modify the convection above the…

Astrophysics · Physics 2009-11-10 C. L. Fryer , M. S. Warren

The literature has not converged onto a precise depiction of the magnetogenesis process for pulsars, and it is profitable to preliminarily but exhaustively assess the viability of the plethora of alternative proposals, before substantial…

High Energy Astrophysical Phenomena · Physics 2026-02-03 Fan Zhang

In the seconds after core collapse and explosion, a thermal neutrino-driven wind emerges from the cooling, deleptonizing newly-born neutron star. If the neutron star has a large-scale magnetar-strength surface magnetic field and millisecond…

Astrophysics · Physics 2010-11-11 Todd A. Thompson

The impact of the magnetic field on postbounce supernova dynamics of non-rotating stellar cores is studied by performing three-dimensional magnetohydrodynamics simulations with spectral neutrino transport. The explodability of strongly and…

High Energy Astrophysical Phenomena · Physics 2022-08-19 Jin Matsumoto , Yuta Asahina , Tomoya Takiwaki , Kei Kotake , Hiroyuki R. Takahashi

Early-type stars have convective cores due to a steep temperature gradient produced by the CNO cycle. These cores can host dynamos, and the generated magnetic fields can be relevant to explain the magnetism observed in Ap/Bp stars. Our main…

Solar and Stellar Astrophysics · Physics 2024-11-27 J. P. Hidalgo , P. J. Käpylä , D. R. G Schleicher , C. A. Ortiz-Rodríguez , F. H. Navarrete

According to our understanding of stellar evolution, early-type stars have radiative envelopes and convective cores due to a steep temperature gradient produced by the CNO cycle. Some of these stars (mainly, the subclasses Ap and Bp) have…

Solar and Stellar Astrophysics · Physics 2023-03-21 J. P. Hidalgo , P. J. Käpylä , C. A. Ortiz-Rodríguez , F. H. Navarrete , B. Toro , D. R. G. Schleicher

A rapidly spinning magnetar in a young supernova (SN) can produce a superluminous transient by converting a fraction of its rotational energy into radiation. Here, we present the first three-dimensional hydrodynamical simulations ever…

High Energy Astrophysical Phenomena · Physics 2020-04-29 Ke-Jung Chen , S. E. Woosley , Daniel J. Whalen

In a newly born (high-temperature and Keplerian rotating) neutron star, r-mode instability can lead to stellar differential rotation, which winds the seed poloidal magnetic field ($\sim 10^{11}$ G) to generate an ultra-high ($\sim 10^{17}$…

High Energy Astrophysical Phenomena · Physics 2014-04-30 Quan Cheng , Yun-Wei Yu

Low-field magnetars have dipolar magnetic fields that are 10-100 times weaker than the threshold, $B \gtrsim 10^{14}$ G, used to define classical magnetars, yet they produce similar X-ray bursts and outbursts. Using the first direct…

High Energy Astrophysical Phenomena · Physics 2025-01-10 Andrei Igoshev , Paul Barrère , Raphaël Raynaud , Jérome Guilet , Toby Wood , Rainer Hollerbach

Core-collapse supernovae are accompanied by formation of neutron stars. The gravitation energy is transformed into the energy of the explosion, observed as SN II, SN Ib,c type supernovae. We present results of 2-D MHD simulations, where the…

High Energy Astrophysical Phenomena · Physics 2014-08-12 G. S. Bisnovatyi-Kogan , S. G. Moiseenko , N. V. Ardeljan

Neutron stars, and magnetars in particular, are known to host the strongest magnetic fields in the Universe. The origin of these strong fields is a matter of controversy. In this preliminary work, via numerical simulations, we study, for…

High Energy Astrophysical Phenomena · Physics 2020-06-30 K. Franceschetti , L. Del Zanna

During the first 40 s after their birth, proto-neutron stars are expected to be subject to at least two types of instability: the convective instability and the neutron-finger one. Both instabilities involve convective motions and hence can…

Astrophysics · Physics 2009-06-23 L. Naso , L. Rezzolla , A. Bonanno , L. Paternò

Magnetars are neutron stars in which a strong magnetic field is the main energy source. About two dozens of magnetars, plus several candidates, are currently known in our Galaxy and in the Magellanic Clouds. They appear as highly variable…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Sandro Mereghetti , Jose' Pons , Andrew Melatos

The magnetar magnetosphere is gradually twisted by shearing from footpoint motion, and stored magnetic energy also increases at the same time. When a state exceeds a threshold, flares/outbursts manifest themselves as a result of a…

High Energy Astrophysical Phenomena · Physics 2018-04-25 Yasufumi Kojima

We consider a model where the strong magnetic fields of magnetars arise from a high baryon density, magnetized core. In this framework magnetars are distinguished from pulsars by their higher masses and central density. For magnetars, as…

Solar and Stellar Astrophysics · Physics 2015-05-20 N. D. Hari Dass , Vikram Soni

Magnetic braking causes the spin-down of single stars as they evolve on the main sequence. Models of magnetic braking can also explain the evolution of close binary systems, including cataclysmic variables. The well-known period gap in the…

Solar and Stellar Astrophysics · Physics 2012-02-24 G. A. J. Hussain

We discuss the mean-field dynamo action in protoneutron stars that are subject to instabilities during the early evolutionary phase. The mean field is generated in the neutron-finger unstable region where the Rossby number is $\sim 1$ and…

Astrophysics · Physics 2009-11-11 A. Bonanno , V. Urpin , G. Belvedere

Persistent high-energy emission of magnetars is produced by a plasma corona around the neutron star, with total energy output of ~10^{36}erg/s. The corona forms as a result of occasional starquakes that twist the external magnetic field of…

Astrophysics · Physics 2008-11-26 A. M. Beloborodov , C. Thompson