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Related papers: Magnetic field inference in active region coronal …

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A ubiquitous presence of weak energy releases is one of the most promising hypotheses to explain coronal heating, referred to as the nanoflare hypothesis. The accelerated electrons associated with such weak heating events are also expected…

Solar and Stellar Astrophysics · Physics 2022-10-12 Rohit Sharma , Divya Oberoi , Marina Battaglia , Sam Krucker

We have performed microwave diagnostics of the magnetic field strengths in solar flare loops based on the theory of gyrosynchrotron emission. From Nobeyama Radioheliograph observations of three flare events at 17 and 34 GHz, we obtained the…

Solar and Stellar Astrophysics · Physics 2020-06-30 Rui Zhu , Baolin Tan , Yingna Su , Hui Tian , Yu Xu , Xingyao Chen , Yongliang Song , Guangyu Tan

In addition to the `facular' brightening of active regions, the quiet Sun also contains a small scale magnetic field with associated brightenings in continuum radiation. We measure this contribution of quiet regions to the Sun's brightness…

Solar and Stellar Astrophysics · Physics 2011-08-11 R. S. Schnerr , H. C. Spruit

The coronal magnetic field is an important quantity because the magnetic field dominates the structure of the solar corona. Unfortunately direct measurements of coronal magnetic fields are usually not available. The photospheric magnetic…

Astrophysics · Physics 2009-06-25 T. Wiegelmann

Oscillation properties in two sunspots and two facular regions are studied using Solar Dynamics Observatory (SDO) data and ground-based observations in the SiI 10827 and HeI 10830 lines. The aim is to study different-frequency spatial…

Solar and Stellar Astrophysics · Physics 2014-11-25 N. I. Kobanov , D. Y. Kolobov , A. A. Chelpanov

The coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay et al. A time sequence of cleaned photospheric…

Solar and Stellar Astrophysics · Physics 2021-01-13 Stephanie L. Yardley , Duncan H. Mackay , Lucie M. Green

The magnetic field shapes the structure of the solar corona but we still know little about the interrelationships between the coronal magnetic field configurations and the resulting quasi-stationary structures observed in coronagraphic…

We have examined the global structure of the solar magnetic field using data from the FeI spectral line at {\lambda}5250.2{\AA} obtained at the 150-foot tower telescope at the Mt. Wilson Observatory (MWO). For each point on the solar…

Solar and Stellar Astrophysics · Physics 2015-06-15 Roger K. Ulrich , Tham Tran

The large-scale structure of the magnetic field in the solar corona provides the energy to power large-scale solar eruptive events. Our physical understanding of this structure, and hence our ability to predict these events, is limited by…

Solar and Stellar Astrophysics · Physics 2015-08-06 R. T. James McAteer

Magnetism defines the complex and dynamic solar corona. Twists and tangles in coronal magnetic fields build up energy and ultimately erupt, hurling plasma into interplanetary space. These coronal mass ejections (CMEs) are transient riders…

Solar and Stellar Astrophysics · Physics 2017-11-28 Sarah Gibson

Presently, many models of the coronal magnetic field rely on photospheric vector magnetograms but these data have been shown to be problematic as the sole boundary information for nonlinear force-free field (NLFFF) extrapolations. Magnetic…

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

Solar flares are driven by release of free magnetic energy and often associated with restructurization of the magnetic field topology. Yet, observations of evolving magnetic field in the flaring volume are limited to very few cases…

Solar and Stellar Astrophysics · Physics 2026-02-18 Gregory D. Fleishman , Tatyana Kaltman , Sijie Yu

The interaction of magnetic fields and convection is investigated in the context of the coronal heating problem. We study the motions of photospheric magnetic elements using filtergrams obtained at the Swedish Vacuum Solar Telescope at La…

We analyze spectropolarimetric observations of the chromospheric Ca II 8542 A line taken by the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope. The data were observed on 2012 January 29 for the NOAA active…

Solar and Stellar Astrophysics · Physics 2017-12-20 Ali G. A. Abdelkawy , Abdelrazek M. K. Shaltout , M. M. Beheary , T. A. Schad

Measuring the physical parameters of Coronal Mass Ejections (CMEs), particularly their entrained magnetic field, is crucial for understanding their physics and for assessing their geo-effectiveness. At the moment, only remote sensing…

Solar and Stellar Astrophysics · Physics 2020-08-13 Surajit Mondal , Divya Oberoi , Angelos Vourlidas

The theoretical concept that braided magnetic field lines in the solar corona may dissipate a sufficient amount of energy to account for the brightening observed in the active-region corona, has been substantiated by high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-17 J. K. Thalmann , S. K. Tiwari , T. Wiegelmann

The problem of solar chromospheric heating remains a challenging one with wider implications for stellar physics. Several studies in the recent past have shown that small-scale inclined magnetic field elements channel copious amount of…

Solar and Stellar Astrophysics · Physics 2018-12-14 S. P. Rajaguru , C. R. Sangeetha , Durgesh Tripathi

Hot channels (HCs), high temperature erupting structures in the lower corona of the Sun, have been proposed as a proxy of magnetic flux ropes (MFRs) since their initial discovery. However, it is difficult to make definitive proof given the…

Solar and Stellar Astrophysics · Physics 2015-08-06 Hongqiang Song , Yao Chen , Jie Zhang , Xin Cheng , Bing Wang , Qiang Hu , Gang Li , Yuming Wang

Solar coronal rain is classified generally into two categories: flare-driven and quiescent coronal rain. The latter is observed to form along both closed and open magnetic field structures. Recently, we proposed that some of the quiescent…

Solar and Stellar Astrophysics · Physics 2021-10-14 Leping Li , Hardi Peter , Lakshmi Pradeep Chitta , Hongqiang Song

Magnetic loops filled with hot plasma are the main building blocks of the solar corona. Usually they have lengths of the order of the barometric scale height in the corona that is 50 Mm. Previously it has been suggested that miniature…

Solar and Stellar Astrophysics · Physics 2017-03-15 Krzysztof Barczynski , Hardi Peter , Sabrina L. Savage
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