English
Related papers

Related papers: Image-Optimized Coronal Magnetic Field Models

200 papers

The magnetic field governs the corona; hence it is a crucial parameter to measure. Unfortunately, existing techniques for estimating its strength are limited by strong assumptions and limitations. These techniques include photospheric or…

Solar and Stellar Astrophysics · Physics 2022-10-26 Juan Martinez-Sykora , Viggo H. Hansteen , Bart De Pontieu , Enrico Landi

Context. The potential field source surface model is frequently used as a basis for further scientific investigations where a comprehensive coronal magnetic field is of importance. Its parameters, especially the position and shape of the…

Solar and Stellar Astrophysics · Physics 2020-07-01 Martin Kruse , Verena Heidrich-Meisner , R. F. Wimmer-Schweingruber , Michael Hauptmann

Direct solar coronal magnetic field measurements have become possible since recent development of high-sensitivity infrared detection technology. The SOLARC instrument installed on Mt. Haleakala is such a polarimetric coronagraph that was…

Astrophysics · Physics 2008-09-05 Y. Liu , H. Lin

The Potential Field Source Surface (PFSS) model is the most used approach for extrapolating the global coronal magnetic field, offering efficiency and strong performance at large scales. However, PFSS assumes a potential coronal field, so…

Solar and Stellar Astrophysics · Physics 2026-03-23 C. Antonio , I. Chifu , R. Gafeira , J. J. G. Lima

We present a formalism for performance forecasting and optimization of future cosmic microwave background (CMB) experiments. We implement it in the context of nearly full sky, multifrequency, B-mode polarization observations, incorporating…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Josquin Errard , Federico Stivoli , Radek Stompor

In the field of corona discharges, the complex chemical mechanisms inside the ionization region have prompted the development of simplified models to replicate the macroscopic effects of ion generation, thereby reducing the computational…

Much of our understanding of the state of coronal plasmas comes from observations that are optically thin. This means that light travels freely through the corona without being materially affected by it, which allows it to be easily seen…

Solar and Stellar Astrophysics · Physics 2021-12-08 Joseph Plowman

We propose and analyze a constrained level-set method for semi-automatic image segmentation. Our level-set model with constraints on the level-set function enables us to specify which parts of the image lie inside respectively outside the…

Numerical Analysis · Mathematics 2014-12-11 Vladimír Klement , Tomáš Oberhuber , Daniel Ševčovič

We propose and analyze a constrained level-set method for semi-automatic image segmentation. Our level-set model with constraints on the level-set function enables us to specify which parts of the image lie inside respectively outside the…

Numerical Analysis · Mathematics 2015-01-07 Vladimír Klement , Tomáš Oberhuber , Daniel Ševčovič

Knowledge regarding the coronal magnetic field is important for the understanding of many phenomena, like flares and coronal mass ejections. Because of the low plasma beta in the solar corona the coronal magnetic field is often assumed to…

Astrophysics · Physics 2008-11-26 Thomas Wiegelmann , Bernd Inhester , Takashi Sakurai

Coronal holes (CHs) are regions with unbalanced magnetic flux, and have been associated with open magnetic field (OMF) structures. However, it has been reported that some CHs do not intersect with OMF regions. To investigate the…

Solar and Stellar Astrophysics · Physics 2022-07-27 Guan-Han Huang , Chia-Hsien Lin , Lou-Chuang Lee

Estimating the magnetic field strength in the solar corona is crucial for understanding different physical processes happening over diverse spatio-temporal scales. However, the high temperatures and low density of the solar corona make this…

Solar and Stellar Astrophysics · Physics 2024-03-07 Upasna Baweja , Vaibhav Pant , Iñigo Arregui

The current generation of ground-based coronagraphic instruments uses deformable mirrors to correct for phase errors and to improve contrast levels at small angular separations. Improving these techniques, several space and ground based…

Instrumentation and Methods for Astrophysics · Physics 2017-10-12 Johan Mazoyer , Laurent Pueyo

In recent years, machine learning (ML) based reconstruction has been widely investigated and employed in cardiac magnetic resonance (CMR) imaging. ML-based reconstructions can deliver clinically acceptable image quality under substantially…

Image and Video Processing · Electrical Eng. & Systems 2024-11-18 Chi Zhang , Michael Loecher , Cagan Alkan , Mahmut Yurt , Shreyas S. Vasanawala , Daniel B. Ennis

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

Magnetic field is the key physical quantity in solar physics as it controls all kinds of solar activity, ranging from nanoflares to big flares and coronal mass ejections (CMEs). However, so far only the magnetic field on the solar surface…

Solar and Stellar Astrophysics · Physics 2025-11-21 P. F. Chen

Context: Knowledge about the coronal magnetic field is important to the understanding the structure of the solar corona. We compute the field in the higher layers of the solar atmosphere from the measured photospheric field under the…

Solar and Stellar Astrophysics · Physics 2014-11-20 T. Tadesse , T. Wiegelmann , B. Inhester

Directly observing exoplanets with coronagraphs is impeded by the presence of speckles from aberrations in the optical path, which can be mitigated in hardware with wavefront control as well as in post-processing. This work explores using…

Instrumentation and Methods for Astrophysics · Physics 2025-04-03 Yinzi Xin , Laurent Pueyo , Romain Laugier , Leonid Pogorelyuk , Ewan S. Douglas , Benjamin J. S. Pope , Kerri L. Cahoy

Using the latest physical modeling and constrained by the most recent data, we develop a phenomenological parameterized model of the contributions to intensity and polarization maps at millimeter wavelengths from external galaxies and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Marius Millea , Olivier Doré , Jonathan Dudley , Gilbert Holder , Lloyd Knox , Laurie Shaw , Yong-Seon Song , Oliver Zahn

Measurements of the magnetic field in the stellar coronae are extremely difficult. Recently, it was proposed that the magnetic-field-induced transition (MIT) of the Fe X 257 {\AA} line can be used to measure the coronal magnetic field of…

Solar and Stellar Astrophysics · Physics 2021-09-08 Yajie Chen , Xianyu Liu , Hui Tian , Xianyong Bai , Meng Jin , Wenxian Li , Yang Yang , Zihao Yang , Yuanyong Deng
‹ Prev 1 3 4 5 6 7 10 Next ›