English
Related papers

Related papers: Reconstruction of Coronal Magnetic Fields Using a …

200 papers

Coronal magnetic flux ropes are closely related to large-scale solar activities. Using a 2.5-dimensional time-dependent ideal magnetohydrodynamic (MHD) model in Cartesian coordinates, we carry out numerical simulations to investigate the…

Solar and Stellar Astrophysics · Physics 2017-12-27 Quanhao Zhang , Yuming Wang , Youqiu Hu , Rui Liu , Kai Liu , Jiajia Liu

In recent years, interest in expanding from 2D to 3D systems has grown in the magnetism community, from exploring new geometries to broadening the knowledge on the magnetic textures present in thick samples, and with this arise the need for…

We present an efficient method for propagating the time-dependent Kohn-Sham equations in free space, based on the recently introduced Fourier contour deformation (FCD) approach. For potentials which are constant outside a bounded domain,…

Chemical Physics · Physics 2023-07-10 Jason Kaye , Alex Barnett , Leslie Greengard , Umberto De Giovannini , Angel Rubio

Recent advances in spectropolarimetry have allowed the reconstruction of stellar coronal magnetic fields. This uses Zeeman-Doppler magnetograms of the surface magnetic field as a lower boundary condition. The ZDI maps, however, suffer from…

Solar and Stellar Astrophysics · Physics 2015-05-18 Colin Johnstone , Moira Jardine , Duncan Mackay

We investigate the dynamics of a closed corona cartesian reduced magnetohydrodynamic (MHD) model where photospheric vortices twist the coronal magnetic field lines. We consider two corotating or counter-rotating vortices localized at the…

Solar and Stellar Astrophysics · Physics 2019-10-17 A. F. Rappazzo , M. Velli , R. B. Dahlburg , G. Einaudi

Accurate estimates of the horizontal electric field on the Sun's visible surface are important not only for estimating the Poynting flux of magnetic energy into the corona but also for driving time-dependent magnetohydrodynamic models of…

Solar and Stellar Astrophysics · Physics 2017-02-22 A. R. Yeates

We present a generalized elliptical cylindrical flux rope model for interplanetary coronal mass ejections (ICMEs) that allows for a non zero poloidal component in the internal magnetic field. We introduce a two step reconstruction algorithm…

Solar and Stellar Astrophysics · Physics 2025-12-02 Marti Masso Moreno , Carlos Arturo Perez-Alanis , P. K. Manoharan

Nonlinear force-free solutions for the magnetic field in the solar corona constructed using photospheric vector magnetic field boundary data suffer from a basic problem: the observed boundary data are inconsistent with the nonlinear…

Solar and Stellar Astrophysics · Physics 2009-07-22 M. S. Wheatland , S. Regnier

The reconstruction of current distributions from samples of their induced magnetic field is a challenging problem due to multiple factors. First, the problem of reconstructing general three dimensional current distributions is ill-posed.…

Image and Video Processing · Electrical Eng. & Systems 2024-08-30 Christopher Miller , Adrian Mariano , Sean Oliver , Jacob Lenz , Dmitro Martynowych

Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field…

The three-dimensional (3D) coordinates of stereoscopically triangulated loops provide strong constraints for magnetic field models of active regions in the solar corona. Here we use STEREO/A and B data from some 500 stereoscopically…

Solar and Stellar Astrophysics · Physics 2015-06-05 Markus J. Aschwanden , Jean-Pierre Wuelser , Nariaki V. Nitta , James R. Lemen , Marc L. DeRosa , Anna Malanushenko

We study self-similar analytical solutions for force-free magnetic field in azimuthal symmetry and arcade topology. We assume the existence of a poloidal magnetic field, anchored on a heavy spherical conductor. The field is changed by…

Astrophysics · Physics 2009-11-13 K. N. Gourgouliatos

The dynamics of highly magnetized plasmas in extreme astrophysical environments are effectively modeled by Force-Free Electrodynamics (FFE), a framework essential for studying objects like neutron stars and accreting black holes. The…

General Relativity and Quantum Cosmology · Physics 2025-11-11 Rakshak Adhikari

For the extrapolation of magnetic fields into the solar corona from measurements taken in the photosphere (or chromosphere) force-free magnetic fields are typically used. This does not take into account that the lower layers of the solar…

Solar and Stellar Astrophysics · Physics 2020-01-08 Thomas Neukirch , Thomas Wiegelmann

AIMS: We develop an optimization principle for computing stationary MHD equilibria. METHODS: Our code for the self-consistent computation of the coronal magnetic fields and the coronal plasma uses non-force-free MHD equilibria. Previous…

Astrophysics · Physics 2008-11-26 Thomas Wiegelmann , Thomas Neukirch

Four different approximate approaches used to model the stressing of coronal magnetic fields due to an imposed photospheric motion are compared with each other and the results from a full time-dependent magnetohydrodynamic (MHD) code. The…

Solar and Stellar Astrophysics · Physics 2018-02-28 E. E. Goldstraw , A. W. Hood , P. K. Browning , P. J. Cargill

The magnetic geometry of the surface magnetic fields of more than 55 cool stars have now been mapped using spectropolarimetry. In order to better understand these observations, we compare the magnetic field topology at different surface…

Solar and Stellar Astrophysics · Physics 2017-01-25 L. T. Lehmann , M. M. Jardine , A. A. Vidotto , D. H. Mackay , V. See , J. -F. Donati , C. P. Folsom , S. V. Jeffers , S. C. Marsden , J. Morin , P. Petit

Magnetic field extrapolation is a fundamental tool to reconstruct the three-dimensional magnetic field above the solar photosphere. However, the prevalently used force-free field model might not be applicable in the lower atmosphere with…

Solar and Stellar Astrophysics · Physics 2023-07-12 Fu Yu , Jie Zhao , Yang Su , Xiaoshuai Zhu , Yang Guo , Jinhua Shen , Hui Li

We present a novel type of neural fields that uses general radial bases for signal representation. State-of-the-art neural fields typically rely on grid-based representations for storing local neural features and N-dimensional linear…

Computer Vision and Pattern Recognition · Computer Science 2023-09-28 Zhang Chen , Zhong Li , Liangchen Song , Lele Chen , Jingyi Yu , Junsong Yuan , Yi Xu

Purpose: Recent developments in hardware design enable the use of Fast Field-Cycling (FFC) techniques in MRI to exploit the different relaxation rates at very low field strength, achieving novel contrast. The method opens new avenues for in…

Signal Processing · Electrical Eng. & Systems 2021-05-19 Markus Bödenler , Oliver Maier , Rudolf Stollberger , Lionel M. Broche , P. James Ross , Mary-Joan MacLeod , Hermann Scharfetter