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Photospheric magnetic vector maps from two different instruments are used to model the nonlinear force-free coronal magnetic field above an active region. We use vector maps inferred from polarization measurements of the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2015-06-15 J. K. Thalmann , S. K. Tiwari , T. Wiegelmann

We have developed a general framework for modeling gyrosynchrotron and free-free emission from solar flaring loops and used it to test the premise that 2D maps of source parameters, particularly magnetic field, can be deduced from spatially…

Solar and Stellar Astrophysics · Physics 2015-06-15 Dale E. Gary , Gregory D. Fleishman , Gelu M. Nita

Nonlinear Force-free Field (NLFFF) models are widely used to investigate coronal magnetic field structure in solar active regions, but methods to validate them remain limited. Here, we use Gaussian separation, recently applied to solar…

Solar and Stellar Astrophysics · Physics 2026-05-12 Abhinav G. Iyer , Michael S. Wheatland , Brian T. Welsch , Yang Liu , S. A. Gilchrist

We develop a practical forward fitting method based on the SIMPLEX algorithm with shaking, which allows the derivation of the magnetic field and other parameters along a solar flaring loop using microwave imaging spectroscopy of…

Solar and Stellar Astrophysics · Physics 2011-02-11 Gregory D. Fleishman , Gelu M. Nita , Dale E. Gary

We present a code for solving the nonlinear force-free equations in spherical polar geometry, with the motivation of modeling the magnetic field in the corona. The code is an implementation of the Grad-Rubin method. Our method is applicable…

Solar and Stellar Astrophysics · Physics 2016-10-28 S. A. Gilchrist , M. S. Wheatland

In the quiet solar photosphere, the mixed polarity fields form a magnetic carpet, which continuously evolves due to dynamical interaction between the convective motions and magnetic field. This interplay is a viable source to heat the solar…

Solar and Stellar Astrophysics · Physics 2014-09-16 L. P. Chitta , R. Kariyappa , A. A. van Ballegooijen , E. E. DeLuca , S. K. Solanki

Circuit models involving bulk currents and inductances are often used to estimate the energies of coronal magnetic field configurations, in particular configurations associated with solar flares. The accuracy of circuit models is tested by…

Astrophysics · Physics 2009-11-10 M. S. Wheatland , F. J. Farvis

Coronal magnetic fields evolve quasi statically over long time scales and dynamically over short time scales. As of now there exists no regular measurements of coronal magnetic fields, and therefore generating the coronal magnetic field…

Solar and Stellar Astrophysics · Physics 2023-12-20 P. Vemareddy , Jörn Warnecke , Ph. A. Bourdin

(abridged) Pulsar activity and its related radiation mechanism are usually explained by invoking some plasma processes occurring inside the magnetosphere. Despite many detailed local investigations, the global electrodynamics around those…

High Energy Astrophysical Phenomena · Physics 2015-06-05 J. Pétri

In the solar corona, magnetic flux rope is believed to be a fundamental structure accounts for magnetic free energy storage and solar eruptions. Up to the present, the extrapolation of magnetic field from boundary data is the primary way to…

Solar and Stellar Astrophysics · Physics 2016-01-20 Chaowei Jiang , Xueshang Feng

Solar flare simulations are commonly initialised using non-linear force free field (NLFF) extrapolations derived from photospheric vector magnetograms. However, the force free assumption neglects plasma forces and may limit the available…

Solar and Stellar Astrophysics · Physics 2026-05-15 W. Bate , M. Gordovskyy , A. Prasad , A. S. Brun , A. Strugarek , M. V. Sieyra , P. Browning , S. Inoue , K. Matsumoto , A. Roddanavar

The aim of this study is to explore the suitability of chromospheric images for magnetic modeling of active regions. We use high-resolution images (0.1") from the Interferometric Bidimensional Spectrometer (IBIS) in the Ca II 8542 A line,…

Solar and Stellar Astrophysics · Physics 2016-07-25 M. J. Aschwanden , K. Reardon , D. Jess

Magnetization of a ferromagnetic substance in response to an externally applied magnetic field increases with the strength of the field. This is because at the microscopic level, magnetic moments in certain regions or domains of the…

Machine Learning · Computer Science 2025-12-12 Vijay Prakash S

Magnetic field plays an important role in various solar eruptions like flares, coronal mass ejections, etc. The formation and evolution of characteristic magnetic field topology in solar eruptions are critical problems that will ultimately…

Solar and Stellar Astrophysics · Physics 2023-06-07 Wen He , Qiang Hu , Ju Jing , Haimin Wang , Chaowei Jiang , Sushree S. Nayak , Avijeet Prasad

The non-dissipative relativistic force-free condition should be a good approximation to describe the electromagnetic field in much of the pulsar magnetosphere, but we may plausibly expect it to break down in singular domains.…

Astrophysics · Physics 2009-11-10 Simon P. Goodwin , Jonathan Mestel , Leon Mestel , Geoffrey A. E. Wright

Context. High resolution magnetic field measurements are routinely done only in the solar photosphere. Higher layers like the chromosphere and corona can be modeled by extrapolating the photospheric magnetic field upward. In the solar…

Solar and Stellar Astrophysics · Physics 2020-08-26 Xiaoshuai Zhu , Thomas Wiegelmann , Sami Solanki

We present the first part of a project on the global energetics of solar flares and coronal mass ejections (CMEs) that includes about 400 M- and X-class flares observed with AIA and HMI onboard SDO. We calculate the potential energy, free…

Solar and Stellar Astrophysics · Physics 2014-12-02 Markus J. Aschwanden , Yan Xu , Ju Jing

General relativistic force-free electrodynamics is one possible plasma-limit employed to analyze energetic outflows in which strong magnetic fields are dominant over all inertial phenomena. The amazing images of black hole shadows from the…

Computational Physics · Physics 2021-03-09 J. F. Mahlmann , M. A. Aloy , V. Mewes , P. Cerdá-Durán

Vector magnetogram data are often used as photospheric boundary conditions for force-free coronal magnetic field extrapolations. In general, however, vector magnetogram data are not consistent with the force-free assumption. In this…

Solar and Stellar Astrophysics · Physics 2020-08-26 Alpha Mastrano , Kai E. Yang , Michael S. Wheatland

The present study provides statistical information on the coronal magnetic field and intensity properties of small-scale bright and faint loops in the quiet Sun. We aim to quantitatively investigate the morphological and topological…

Solar and Stellar Astrophysics · Physics 2024-10-16 Maria S. Madjarska , Thomas Wiegelmann , Pascal Démoulin , Klaus Galsgaard
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