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Related papers: Super-strong Magnetic Field in Sunspots

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A variety of observations suggest that magnetic fields are present in all galaxies and galaxy clusters. These fields are characterized by a modest strength (10^{-7}-10^{-5} G) and huge spatial scale (~Mpc). It is generally assumed that…

Astrophysics · Physics 2008-11-26 Lawrence M. Widrow

This publication provides an overview of magnetic fields in the solar atmosphere with the focus lying on the corona. The solar magnetic field couples the solar interior with the visible surface of the Sun and with its atmosphere. It is also…

Solar and Stellar Astrophysics · Physics 2015-06-23 Thomas Wiegelmann , Julia K. Thalmann , Sami K. Solanki

Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the `salt and pepper' patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations we find that…

Solar and Stellar Astrophysics · Physics 2015-08-19 I. N. Kitiashvili , A. G. Kosovichev , N. N. Mansour , A. A. Wray

We present numerical 2D magnetostatic models for sunspot penumbrae consisting of radially aligned field-free gaps in a potential magnetic field, as proposed by Spruit and Scharmer (2006). The shape of the gaps and the field configurations…

Astrophysics · Physics 2009-11-11 G. B. Scharmer , H. C. Spruit

The goal of this work is to study the magnetic fields of six young solar-analogue stars both individually, and collectively, to search for possible magnetic field trends with age. If such trends are found, they can be used to understand…

Solar and Stellar Astrophysics · Physics 2016-09-07 L. Rosén , O. Kochukhov , T. Hackman , J. Lehtinen

We present new generation mechanisms of magnetic fields in supernova remnant shocks propagating to partially ionized plasmas in the early universe. Upstream plasmas are dissipated at the collisionless shock, but hydrogen atoms are not…

High Energy Astrophysical Phenomena · Physics 2022-09-08 Shuhei Kashiwamura , Yutaka Ohira

Our Universe is full of regions where extreme physical conditions are realized. A most intriguing case is the super-dense core of neutron stars, some of which also have super-strong magnetic fields, hence called magnetars. In this paper we…

High Energy Physics - Phenomenology · Physics 2009-05-01 Efrain J. Ferrer , Vivian de la Incera

Results of a 3D MHD simulation of a sunspot with a photospheric size of about 20 Mm are presented. The simulation has been carried out with the MURaM code, which includes a realistic equation of state with partial ionization and radiative…

Astrophysics · Physics 2011-02-11 M. Rempel , M. Schuessler , M. Knoelker

The data from solar neutrino experiments together with standard solar model predictions are used in order to derive the possible profile of the magnetic field inside the Sun, assuming the existence of a sizeable neutrino magnetic moment and…

Astrophysics · Physics 2009-10-30 Joao Pulido

Deciphering and understanding the small-scale magnetic activity of the quiet solar photosphere should help to solve many of the key problems of solar and stellar physics, such as the magnetic coupling to the outer atmosphere and the coronal…

Astrophysics · Physics 2007-05-23 J. Trujillo Bueno , N. Shchukina , A. Asensio Ramos

Since there is 3P2 neutron superfluid in neutron star interior, it can be treated as a system of magnetic dipoles. Under the presence of background magnetic field, the magnetic dipoles tend to align in the same direction. When the…

High Energy Astrophysical Phenomena · Physics 2016-12-15 Qiu-he Peng , Jie Zhang , Men-quan Liu , Chich-gang Chou

The surface magnetic fields of pre-main-sequence stars and zero-age main-sequence stars are notably strong, resulting in the generation of numerous spots and the emission of bright chromospheric lines. Rotational variations in magnetic…

Solar and Stellar Astrophysics · Physics 2025-04-08 Mai Yamashita , Yoichi Itoh , Shin Toriumi

We have investigated the problem of sunspot magnetohydrostatic equilibrium with comprehensive IR sunspot magnetic field survey observations of the highly sensitive Fe I lines at 15650 \AA\ and nearby OH lines. We have found that some…

Solar and Stellar Astrophysics · Physics 2015-05-30 Sarah A. Jaeggli , Haosheng Lin , Han Uitenbroek

Magnetic fields in galaxies are produced via the amplification of seed magnetic fields of unknown nature. The seed fields, which might exist in their initial form in the intergalactic medium, were never detected. We report a lower bound…

High Energy Astrophysical Phenomena · Physics 2014-11-21 Andrii Neronov , Ievgen Vovk

Magnetic fields in our Galaxy and nearby galaxies have been revealed by starlight polarization, polarized emission from dust grains and clouds at millimeter and submillimeter wavelength, the Zeeman effect of spectral lines or maser lines…

Astrophysics of Galaxies · Physics 2013-08-06 JinLin Han

We present a series of numerical sunspot models addressing the subsurface field and flow structure in up to 16 Mm deep domains covering up to 2 days of temporal evolution. Changes in the photospheric appearance of the sunspots are driven by…

Solar and Stellar Astrophysics · Physics 2015-05-28 Matthias Rempel

Extremely strong magnetic fields of the order of $10^{15}\,{\rm G}$ are required to explain the properties of magnetars, the most magnetic neutron stars. Such a strong magnetic field is expected to play an important role for the dynamics of…

High Energy Astrophysical Phenomena · Physics 2017-10-25 Jerome Guilet , Ewald Mueller , Hans-Thomas Janka , Tomasz Rembiasz , Martin Obergaulinger , Pablo Cerda-Duran , Miguel-Angel Aloy

The origin and growth of magnetic fields in galaxies is still something of an enigma. It is generally assumed that seed fields are amplified over time through the dynamo effect, but there are few constraints on the timescale. It has…

The recent discoveries of several reliable events of high energy cosmic rays at an energy above 10^20 eV raise questions about their path through the nearby universe. The two analyses of the Haverah Park data set and the Akeno data set…

Astrophysics · Physics 2009-09-25 Peter L. Biermann , Hyesung Kang , Dongsu Ryu

Efforts to understand unusual weather or abrupt changes in climate have been plagued by deficiencies of the standard solar model (SSM). While it assumes that our primary source of energy began as a homogeneous ball of hydrogen (H) with a…

Astrophysics · Physics 2007-05-23 O. Manuel , B. W. Ninham , S. E. Friberg