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Related papers: Generating neutron-star magnetic fields: three dyn…

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We study the impact of a small-scale dynamo in core-collapse supernovae using a 3D neutrino magnetohydrodynamics simulation of a $15 M_\odot$ progenitor. The weak seed field is amplified exponentially in the gain region once neutrino-driven…

High Energy Astrophysical Phenomena · Physics 2020-08-11 Bernhard Müller , Vishnu Varma

The surface magnetic field strength of white dwarfs is observed to vary from very little to around 10^9 G. Here we examine the proposal that the strongest fields are generated by dynamo action during the common envelope phase of strongly…

Solar and Stellar Astrophysics · Physics 2009-12-12 Adrian T. Potter , Christopher A. Tout

M dwarfs are the most numerous stars in our Galaxy with masses between approximately 0.5 and 0.1 solar mass. Many of them show surface activity qualitatively similar to our Sun and generate flares, high X-ray fluxes, and large-scale…

Solar and Stellar Astrophysics · Physics 2018-01-29 D. Shulyak A. Reiners , A. Engeln , L. Malo , R. Yadav , J. Morin , O. Kochukhov

R-modes can generate strong magnetic fields in the core of accreting millisecond neutron stars (NSs). The diffusion of these fields outside the core causes the growth of the external magnetic field and thus it affects the evolution of the…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Carmine Cuofano , Alessandro Drago , Giuseppe Pagliara

Although protostars and disks are often studied separately owing to numerical and observational challenges, breakthroughs in recent years have highlighted the need to study both objects in concert. The role of magnetic fields in this regard…

Solar and Stellar Astrophysics · Physics 2025-04-30 Adnan Ali Ahmad , Matthias González , Patrick Hennebelle , Ugo Lebreuilly , Benoît Commerçon

Central compact objects are radio-quite young neutron stars associated with supernova remnants. They have relatively small dipole fields, $B_{\rm p} \sim 10^{10}\,{\rm G}$ as inferred from their spin parameters. X-ray observations and…

High Energy Astrophysical Phenomena · Physics 2026-03-24 Kazım Yavuz Ekşi , İrem Bakır

Neutrino interactions play a central role in transport and flavor evolution in the ejecta of binary neutron star mergers. Simulations suggest that neutron star mergers may produce magnetic fields as strong as $10^{17}$ G, but computational…

High Energy Astrophysical Phenomena · Physics 2026-04-10 Mia Kumamoto , Catherine Welch

We investigate the evolution of magnetized protoneutron stars (PNSs) through four schematic stages: neutrino trapped, deleptonization, neutrino transparent, and the final cold, catalyzed neutron star (NS). Using a quasi static approximation…

High Energy Astrophysical Phenomena · Physics 2026-01-08 Harsh Chandrakar , Adamu Issifu , Prashant Thakur , T. K. Jha , Aravind Taridalu

We examine the impact of the magnetic field on Population III star formation by varying the magnetic field strength. We perform simulations with magnetic field strengths ranging from $10^{-20}$ G to $10^{-4}$ G, in addition to a model…

Solar and Stellar Astrophysics · Physics 2025-05-28 Masahiro N. Machida , Shingo Hirano , Shantanu Basu

Initial distributions of pulsar periods and magnetic fields are essential components of multiple modern astrophysical models. Not enough work has been done to properly constrain these distributions using direct measurements. Here we aim to…

As a massive star evolves through multiple stages of nuclear burning on its way to becoming a supernova, a complex, differentially rotating structure is set up. Angular momentum is transported by a variety of classic instabilities, and also…

Astrophysics · Physics 2009-11-10 A. Heger , S. E. Woosley , H. C. Spruit

There exists both theoretical and observational evidence that the magnetic field decay in neutron stars may proceed in a pronounced non--linear way during a certain episode of the neutron star's life. In the presence of a strong magnetic…

Astrophysics · Physics 2009-11-07 U. Geppert , M. Rheinhardt

The gas from which stars form is magnetized, and strong magnetic fields can efficiently transport angular momentum. Most theoretical models of this phenomenon find that it should prevent formation of large (>100 AU), rotationally-supported…

Solar and Stellar Astrophysics · Physics 2015-06-12 Mark R. Krumholz , Richard M. Crutcher , Charles L. H. Hull

We investigate the impact of strong initial magnetic fields in core-collapse supernovae of non-rotating progenitors by simulating the collapse and explosion of a 16.9 Msun star for a strong- and weak-field case assuming a twisted-torus…

High Energy Astrophysical Phenomena · Physics 2022-11-30 Vishnu Varma , Bernhard Mueller , Fabian R. N. Schneider

The coupling between axions and photons modifies Maxwell's equations, introducing a dynamo term in the magnetic induction equation. In neutron stars, for critical values of the axion decay constant and axion mass, the magnetic dynamo…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Filippo Anzuini , José A. Pons , Antonio Gómez-Bañón , Paul D. Lasky , Federico Bianchini , Andrew Melatos

Beginning with cosmological initial conditions at z=100, we simulate the effects of magnetic fields on the formation of Population III stars and compare our results with the predictions of Paper I. We use Gadget-2 to follow the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-04 Athena Stacy , Christopher F. McKee , Aaron T. Lee , Richard I. Klein , Pak Shing Li

The self-consistent approach to the magnetic field evolution in neutron star cores, developed recently, is generalised to the case of superfluid and superconducting neutron stars. Applying this approach to the cold matter of neutron star…

High Energy Astrophysical Phenomena · Physics 2020-10-21 Mikhail E. Gusakov , Elena M. Kantor , Dmitry D. Ofengeim

All cool main sequence stars including our Sun are thought to have magnetic fields. Observations of the Sun revealed that even in quiet regions small-scale turbulent magnetic fields are present. Simulations further showed that such magnetic…

Solar and Stellar Astrophysics · Physics 2023-02-01 V. Witzke , H. B. Duehnen , A. I. Shapiro , D. Przybylski , T. S. Bhatia , R. Cameron , S. K. Solanki

Stellar magnetic dynamos are driven by rotation, rapidly rotating stars produce stronger magnetic fields than slowly rotating stars do. The Zeeman effect is the most important indicator of magnetic fields, but Zeeman broadening must be…

Solar and Stellar Astrophysics · Physics 2015-06-17 Ansgar Reiners

Initially, we present our original fast dynamo mechanism being potentially at work concerning the Sun and the solar type stars. Then, based on this new prototype model, a dynamo action model explaining the generation of the magnetic fields…

Solar and Stellar Astrophysics · Physics 2019-03-21 D. V. Sarafopoulos