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For several decades we have been cognizant of the presence of magnetic fields in early-type stars, but our understanding of their magnetic properties has recently (over the last decade) expanded due to the new generation of high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-16 Jason H. Grunhut , Coralie Neiner

One of the possible mechanisms responsible for the panoply of shapes in planetary nebulae is the presence of magnetic fields that drive the ejection of ionized material during the proto-planetary nebula phase. Therefore, detecting magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-18 F. Leone , R. L. M. Corradi , M. J. Martínez González , A. Asensio Ramos , R. Manso Sainz

By performing new, long and numerically accurate general-relativistic simulations of magnetized, equal-mass neutron-star binaries, we investigate the role that realistic magnetic fields may have in the evolution of these systems. In…

General Relativity and Quantum Cosmology · Physics 2011-02-18 Bruno Giacomazzo , Luciano Rezzolla , Luca Baiotti

We report the first experimental observation of reversals of a dynamo field generated in a laboratory experiment based on a turbulent flow of liquid sodium. The magnetic field randomly switches between two symmetric solutions B and -B. We…

Detecting coherent radio bursts from nearby M dwarfs provides opportunities for exploring their magnetic activity and interaction with orbiting exoplanets. However, it remains uncertain if the emission is related to flare-like activity…

We investigate the evolution of magnetic fields in galaxy clusters starting from constant primordial fields using highly resolved ($\approx \rm 4 ~kpc$) cosmological MHD simulations. The magnetic fields in our sample exhibit amplification…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Paola Domínguez-Fernández , Franco Vazza , Marcus Brüggen , Gianfranco Brunetti

Stellar dynamos generate magnetic fields that are of fundamental importance to the variability and evolution of Sun-like and low-mass stars, and for the development of their planetary systems. We report measurements of surface-average…

We report the results of our study of magnetic fields in a sample of Be stars using spectropolarimetric data obtained at the European Southern Observatory with the multi-mode instrument FORS1 installed at the 8m Kueyen telescope. The…

Solar and Stellar Astrophysics · Physics 2009-11-13 R. Yudin , S. Hubrig , M. Pogodin , I. Savanov , M. Schoeller , G. Peters , M. Cure

Earlier Enqvist and Olesen have shown that formation of ferromagnetic planar walls in vacuum at GUT scales in comoving plasmas may generate a large scale magnetic field of $B_{now}\simeq{10^{-14}G}$. In this paper we show that starting from…

General Relativity and Quantum Cosmology · Physics 2015-06-18 L. C. Garcia de Andrade

We review the literature concerning how the cosmic magnetic fields pervading nearly all galaxies actually got started. some observational evidence involves the chemical abundance of the light elements Be and B, while another one is based on…

Astrophysics · Physics 2009-11-13 Russell M. Kulsrud , Ellen G. Zweibel

It is now well-known that the surface magnetic fields observed in cool, lower-mass stars on the main sequence (MS) are generated by dynamos operating in their convective envelopes. However, higher-mass stars (above 1.5 Msun) pass their MS…

Astrophysics · Physics 2009-11-13 E. Alecian , G. A. Wade , C. Catala

Primordial magnetic fields could explain the large-scale magnetic fields present in the Universe. Inflation and phase transitions in the early Universe could give rise to such fields with unique characteristics. We investigate the…

We present a model for the seeding and evolution of magnetic fields in protogalaxies. Supernova (SN) explosions during the assembly of a protogalaxy provide magnetic seed fields, which are subsequently amplified by compression, shear flows…

Astrophysics of Galaxies · Physics 2015-06-16 Alexander M. Beck , Klaus Dolag , Harald Lesch , Philipp P. Kronberg

Models of rotationally-driven dynamos in stellar radiative zones have suggested that magnetohydrodynamic transport of angular momentum and chemical composition can dominate over the otherwise purely hydrodynamic processes. A proper…

Solar and Stellar Astrophysics · Physics 2015-06-05 Adrian T. Potter , Shashikumar M. Chitre , Christopher A. Tout

EK Eri is one of the most slowly rotating active giants known, and has been proposed to be the descendant of a strongly magnetic Ap star. We have performed a spectropolarimetric study of EK Eri over 4 photometric periods with the aim of…

Thanks to the recent very high-precision photometry of red giants from satellites such as Kepler, precise mass and radius values as well as accurate information of evolutionary stages are already established by asteroseismic approach for a…

Solar and Stellar Astrophysics · Physics 2015-06-24 Yoichi Takeda , Akito Tajitsu

Observations of dwarf galaxies suggest the presence of large-scale magnetic fields. However the size and slow rotation of these galaxies appear insufficient to support a mean-field dynamo action to excite such fields. Here we suggest a new…

Astrophysics of Galaxies · Physics 2017-02-08 David Moss , Dmitri Sokoloff

We present three-dimensional global numerical simulations of the cosmic-ray (CR) driven dynamo in barred galaxies. We study the evolution of the interstellar medium of the barred galaxy in the presence of non-axisymmetric component of the…

Astrophysics of Galaxies · Physics 2011-06-02 K. Kulpa-Dybeł , K. Otmianowska-Mazur , B. Kulesza-Żydzik , G. Kowal , M. Hanasz , D. Wóltański , K. Kowalik

We investigate the evolution of magnetic fields generated by the crystallization-driven dynamo in carbon-oxygen white dwarfs (WDs) with masses $\lesssim1.05\ M_{\odot}$. We use scalings for the dynamo to demonstrate that the initial…

Solar and Stellar Astrophysics · Physics 2024-10-31 Matias Castro-Tapia , Shu Zhang , Andrew Cumming

Red Giant stars host solar-like oscillations which have mixed character, being sensitive to conditions both in the outer convection zone and deep within the interior. The properties of these modes are sensitive to both core rotation and…