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

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Stellar magnetism plays an important role in stellar evolution theory. Approximatively 10% of observed main sequence (MS) and pre-main-sequence (PMS) radiative stars exhibit surface magnetic fields above the detection limit, raising the…

Solar and Stellar Astrophysics · Physics 2018-01-24 Jérémie Vidal , David Cébron , Nathanaël Schaeffer , Rainer Hollerbach

The release of spin-down energy by a magnetar is a promising scenario to power several classes of extreme explosive transients. However, it lacks a firm basis because magnetar formation still represents a theoretical challenge. Using the…

High Energy Astrophysical Phenomena · Physics 2020-03-17 Raphaël Raynaud , Jérôme Guilet , Hans-Thomas Janka , Thomas Gastine

We perform the first magnetohydrodynamic simulations in full general relativity of self-consistent rotating neutron stars (NSs) with ultrastrong mixed poloidal and toroidal magnetic fields. The initial uniformly rotating NS models are…

General Relativity and Quantum Cosmology · Physics 2022-02-23 Antonios Tsokaros , Milton Ruiz , Stuart L. Shapiro , Kōji Uryū

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

Formed in the aftermath of a core-collapse supernova or neutron star merger, a hot proto-neutron star (PNS) launches an outflow driven by neutrino heating lasting for up to tens of seconds. Though such winds are considered potential sites…

High Energy Astrophysical Phenomena · Physics 2023-06-08 Dhruv K. Desai , Daniel M. Siegel , Brian D. Metzger

Based on multi-dimensional, multi-group, flux-limited-diffusion hydrodynamic simulations of core-collapse supernovae with the VULCAN/2D code, we study the physical conditions within and in the vicinity of the nascent protoneutron star…

Astrophysics · Physics 2009-11-13 L. Dessart , A. Burrows , E. Livne , C. D. Ott

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

We explore the effects of rapid rotation on the properties of neutrino-heated winds from proto-neutron stars (PNS) formed in core-collapse supernovae or neutron-star mergers by means of three-dimensional general-relativistic hydrodynamical…

High Energy Astrophysical Phenomena · Physics 2022-06-10 Dhruv K. Desai , Daniel M. Siegel , Brian D. Metzger

In order to address the generation of neutron star magnetic fields, with particular focus on the dichotomy between magnetars and radio pulsars, we consider the properties of dynamos as inferred from other astrophysical systems. With…

High Energy Astrophysical Phenomena · Physics 2022-02-23 Christopher J. White , Adam Burrows , Matthew S. B. Coleman , David Vartanyan

Planetary and stellar dynamos likely result from turbulent motions in magnetofluids with kinematic viscosities that are small compared to their magnetic diffusivities. Laboratory experiments are in progress to produce similar dynamos in…

Astrophysics · Physics 2009-11-11 P. D. Mininni

We consider generation and evolution of small-scale magnetic fields in neutron stars. These fields can be generated by small-scale turbulent dynamo action soon after the collapse when the proto-neutron star is subject to convective and…

Astrophysics · Physics 2009-11-10 V. Urpin , J. Gil

An update is given on the current status of solar and stellar dynamos. At present, it is still unclear why stellar cycle frequencies increase with rotation frequency in such a way that their ratio increases with stellar activity. The…

Solar and Stellar Astrophysics · Physics 2015-06-15 Axel Brandenburg

Advances in our understanding and the modeling of stellar core-collapse and supernova explosions over the past 15 years are reviewed, concentrating on the evolution of hydrodynamical simulations, the description of weak interactions and…

Astrophysics · Physics 2008-11-26 H. -Th. Janka , K. Langanke , A. Marek , G. Martinez-Pinedo , B. Mueller

Long-term neutrino-radiation resistive-magnetohydrodynamics simulations in full general relativity are performed for a system composed of a massive neutron star and a torus formed as a remnant of binary neutron star mergers. The simulation…

High Energy Astrophysical Phenomena · Physics 2021-09-21 Masaru Shibata , Sho Fujibayashi , Yuichiro Sekiguchi

The gravitational collapse of rapidly rotating massive stars can lead to the onset of the low $T/\|W\|$ instability within the central proto-neutron star (PNS), which leaves strong signatures in both the gravitational wave (GW) and neutrino…

High Energy Astrophysical Phenomena · Physics 2023-03-08 Matteo Bugli , Jérôme Guilet , Thierry Foglizzo , Martin Obergaulinger

We present three-dimensional simulations of the dynamical bar-mode instability in magnetized and differentially rotating stars in full general relativity. Our focus is on the effects that magnetic fields have on the dynamics and the onset…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Luca Franci , Roberto De Pietri , Kyriaki Dionysopoulou , Luciano Rezzolla

We have investigated the turbulent mean-field dynamo action in protoneutron stars that are subject to convective and neutron finger instabilities. While the first one develops mostly in the inner regions of the star, the second one is…

Astrophysics · Physics 2009-11-10 Alfio Bonanno , Luciano Rezzolla , Vadim Urpin

Magnetic fields can play a major role in the dynamics of outstanding explosions associated to violent events such as GRBs and hypernovae, since they provide a natural mechanism to harness the rotational energy of the central proto-neutron…

High Energy Astrophysical Phenomena · Physics 2021-08-04 Matteo Bugli , Jérôme Guilet , Martin Obergaulinger

M dwarfs are low-mass main-sequence stars, the most numerous type of stars in the solar neighbourhood, which are known to have significant magnetic activity. The aim of this work is to explore the dynamo solutions and magnetic fields of…

Solar and Stellar Astrophysics · Physics 2022-06-29 Carolina A. Ortiz-Rodríguez , Dominik R. G. Schleicher , Petri J. Käpylä , Felipe H. Navarrete

We analyse and determine the effects of modest progenitor rotation in the context of core-collapse supernovae by comparing two separate long-duration three-dimensional simulations of 9 M$_{\odot}$ progenitors, one rotating with an initial…

High Energy Astrophysical Phenomena · Physics 2022-05-04 Matthew S. B. Coleman , Adam Burrows , Christopher J. White