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This study based on longitudinal Zeeman effect magnetograms and spectral line scans investigates the dependence of solar surface magnetic fields on the spectral line used and the way the line is sampled in order to estimate the magnetic…

Astrophysics · Physics 2009-11-13 R. K. Ulrich , L. Bertello , J. E. Boyden , L. Webster

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…

Solar and Stellar Astrophysics · Physics 2020-11-05 Zihao Yang , Hui Tian , Steven Tomczyk , Richard Morton , Xianyong Bai , Tanmoy Samanta , Yajie Chen

We demonstrate the sensitivity of magnetic energy and helicity computations regarding the quality of the underlying coronal magnetic field model. We apply the method of Wiegelmann & Inhester (2010) to a series of SDO/HMI vector…

Solar and Stellar Astrophysics · Physics 2019-07-24 Julia K. Thalmann , Luis Linan , Etienne Pariat , Gherardo Valori

Observations with the Hinode space observatory led to the discovery of predominantly horizontal magnetic fields in the photosphere of the quiet internetwork region. Here we investigate realistic numerical simulations of the surface layers…

Astrophysics · Physics 2009-11-13 O. Steiner , R. Rezaei , W. Schaffenberger , S. Wedemeyer-Böhm

The detailed investigation of the polar magnetic field and its time evolution is one of the major achievements of Hinode. Precise measurements of the polar magnetic field are essential for understanding the solar cycle, as they provide…

Quantifying coronal magnetic field remains a central problem in solar physics. Nowadays the coronal magnetic field is often modelled using nonlinear force-free field (NLFFF) reconstructions, whose accuracy has not yet been comprehensively…

Solar and Stellar Astrophysics · Physics 2018-09-14 Gregory D. Fleishman , Sergey Anfinogentov , Maria Loukitcheva , Ivan Mysh'yakov , Alexey Stupishin

Solar pores are active regions with large magnetic field strengths and apparent simple magnetic configurations. Their properties resemble the ones found for the sunspot umbra although pores do not show penumbra. Therefore, solar pores…

Solar and Stellar Astrophysics · Physics 2016-06-15 C. Quintero Noda , T. Shimizu , B. Ruiz Cobo , Y. Suematsu , Y. Katsukawa , K. Ichimoto

In this paper, we present a systematic study of the force-free field equation for simple axisymmetric configurations in spherical geometry and apply it to the solar active regions. The condition of separability of solutions in the radial…

Solar and Stellar Astrophysics · Physics 2014-05-07 A. Prasad , A. Mangalam , B. Ravindra

The structure of the photospheric vector magnetic field below a dark filament on the Sun is studied using the observations of the Spectro-Polarimeter attached to the Solar Optical Telescope onboard Hinode. Special attention is paid to…

Solar and Stellar Astrophysics · Physics 2019-03-20 Takaaki Yokoyama , Yukio Katsukawa , Masumi Shimojo

Expanding on an earlier work that relied on linear force-free magnetic fields, we self-consistently derive the instantaneous free magnetic energy and relative magnetic helicity budgets of an unknown three-dimensional nonlinear force-free…

Solar and Stellar Astrophysics · Physics 2015-06-11 M. K. Georgoulis , K. Tziotziou , N. -E. Raouafi

The shapes of solar coronal loops are sensitive to the presence of electrical currents that are the carriers of the nonpotential energy available for impulsive activity. We use this information in a new method for modeling the coronal…

Solar and Stellar Astrophysics · Physics 2021-06-29 A. Malanushenko , C. Schrijver , M. L. DeRosa , M. S. Wheatland

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

Recent spectro-polarimetric observations have provided detailed measurements of magnetic field, velocity and intensity during events of magnetic field intensification in the solar photosphere. We consider the temporal evolution of the…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Danilovic , M. Schüssler , S. K. Solanki

The method of solar magnetic field calibration for the filter-based magnetograph is normally the linear calibration method under weak-field approximation that cannot generate the strong magnetic field region well due to the magnetic…

Solar and Stellar Astrophysics · Physics 2021-02-10 Jingjing Guo , Xianyong Bai , Yuanyong Deng , Hui Liu , Jiaben Lin , Jiangtao Su , Xiao Yang , Kaifan Ji

The topology and dynamics of the three-dimensional magnetic field in the solar atmosphere govern various solar eruptive phenomena and activities, such as flares, coronal mass ejections, and filaments/prominences. We have to observe and…

Solar and Stellar Astrophysics · Physics 2017-06-20 Yang Guo , Xin Cheng , M. D. Ding

We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment. CLASP2.1 provided polarization profiles of the Mg~{|sc ii} $h$ and $k$ lines,…

The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun's photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full disk…

Solar and Stellar Astrophysics · Physics 2017-10-18 J. A. Linker , R. M. Caplan , C. Downs , P Riley , Z Mikic , R. Lionello , C. J. Henney , C. N. Arge , Y. Liu , M. L. Derosa , A. Yeates , M. J. Owens

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

Two extrapolation models of the solar coronal magnetic field are compared using magnetogram data from the SDO/HMI instrument. The two models, a horizontal current-current sheet-source surface (HCCSSS) model and a potential field-source…

Solar and Stellar Astrophysics · Physics 2016-05-25 William M. Arden , Aimee A. Norton , Xudong Sun , Xuepu Zhao

We examine whether or not it is possible to derive the field strength distribution of quiet Sun internetwork regions from very high spatial resolution polarimetric observations in the visible. In particular, we consider the case of the…

Astrophysics · Physics 2009-11-13 D. Orozco Suarez , L. R. Bellot Rubio , J. C. del Toro Iniesta
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