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Related papers: Active region chromospheric magnetic fields

200 papers

Context. Understanding the 3D magnetic field as well as the plasma in the chromosphere and transition region is important. One way is to extrapolate the magnetic field and plasma from the routinely measured vector magnetogram on the…

Solar and Stellar Astrophysics · Physics 2021-01-04 Xiaoshuai Zhu , Thomas Wiegelmann , Bernd Inhester

We analyze spectropolarimetric observations of the chromospheric Ca II 8542 line taken by the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope and photospheric Fe I 6302 lines obtained with the Solar Optical…

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

The heating of the Sun's chromosphere remains poorly understood. While progress has been made on understanding what drives the quiet Sun internetwork chromosphere, chromospheric heating in strong magnetic field regions continues to present…

Solar and Stellar Astrophysics · Physics 2013-02-07 J. de la Cruz Rodríguez , B. De Pontieu , M. Carlsson , L. H. M. Rouppe van der Voort

Magneto-static models may overcome some of the issues facing force-free magnetic field extrapolations. So far they have seen limited use and have faced problems when applied to quiet-Sun data. Here we present a first application to an…

Aims. We aim to infer information about the magnetic field in the low solar corona from coronal rain clumps using high-resolution spectropolarimetric observations in the Ca ii 8542 A line obtained with the Swedish 1-m Solar Telescope.…

Solar and Stellar Astrophysics · Physics 2021-06-09 M. Kriginsky , R. Oliver , P. Antolin , D. Kuridze , N. Freij

We investigated the applicability of the weak-field approximation (WFA) for retrieving the depth-dependent line-of-sight (LOS) magnetic field from the spectral region containing the Mg I $b_2$ spectral line and two photospheric Ti I and Fe…

Solar and Stellar Astrophysics · Physics 2022-08-31 Dušan Vukadinović , Ivan Milić , Olga Atanacković

Adopting the thermal free-free emission mechanism, the coronal and chromospheric magnetic fields are derived from the polarization and spectral observations with the Nobeyama Radioheliograph at 1.76 cm. The solar active regions (AR) located…

Solar and Stellar Astrophysics · Physics 2018-02-14 A. Mouner , Abdelrazek M. K. Shaltout , M. M. Beheary , K. A. K. Gadallah , K. A. Edris

The magnetic fields in the solar atmosphere structure the plasma, store free magnetic energy and produce a wide variety of active solar phenomena, like flare and coronal mass ejections(CMEs). The distribution and strength of magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-06-12 Tilaye Tadesse , T. Wiegelmann , K. Olson , P. J. MacNeice

Chromospheric umbral oscillations produce periodic brightenings in the core of some spectral lines, known as umbral flashes. They are also accompanied by fluctuations in velocity, temperature, and, according to several recent works,…

Solar and Stellar Astrophysics · Physics 2021-09-29 T. Felipe , H. Socas Navarro , C. R. Sangeetha , I. Milic

The Chromospheric LAyer SpectroPolarimeter missions, CLASP2 and CLASP2.1, demonstrated that the near-UV spectral region between 279.30 and 280.68 nm is suitable for studying the magnetism of the solar chromosphere. In particular, the…

The fine-structure of magnetic field of a sunspot penumbra in the upper chromosphere is to be explored and compared to that in the photosphere. High spatial resolution spectropolarimetric observations were recorded with the 1.5-meter GREGOR…

Vector magnetic fields of an active region filament in the photosphere and upper chromosphere are obtained from spectro-polarimetric observations recorded with the Tenerife Infrared Polarimeter (TIP II) at the German Vacuum Tower Telescope…

Solar and Stellar Astrophysics · Physics 2015-06-04 Z. Xu , A. Lagg , S. Solanki , Y. Liu

With current observational methods it is not possible to directly measure the magnetic field in the solar corona with sufficient accuracy. Therefore, coronal magnetic field models have to rely on extrapolation methods using photospheric…

Solar and Stellar Astrophysics · Physics 2025-04-24 Lilli Nadol , Thomas Neukirch

The magnetic field of the quiet-Sun chromosphere remains a mystery for solar physicists. The reduced number of chromospheric lines are intrinsically hard to model and only a few of them are magnetically sensitive. In this work, we use a 3D…

Solar and Stellar Astrophysics · Physics 2012-03-22 J. de la Cruz Rodríguez , H. Socas-Navarro , M. Carlsson , J. Leenaarts

We use joint observations obtained with the Hinode space observatory and the Interferometric Bidimensional Spectrometer (IBIS) installed at the DST of the NSO/SP to investigate the morphology and dynamics of (a) non-magnetic and (b)…

Solar and Stellar Astrophysics · Physics 2009-12-18 F. Wöger , S. Wedemeyer-Böhm , T. Rimmele

Understanding structures and evolutions of the magnetic fields and plasma in multiple layers on the Sun is very important. A force-free magnetic field which is an accurate approximation of the solar corona due to the low plasma $\beta$ has…

Solar and Stellar Astrophysics · Physics 2022-03-30 Xiaoshuai Zhu , Thomas Neukirch , Thomas Wiegelmann

Coronal and chromospheric magnetic fields are derived from polarization and spectral observations of the thermal free-free emission using the Nobeyama Radioheliograph (NoRH). In magnetized plasma, the ordinary and extraordinary modes of…

Solar and Stellar Astrophysics · Physics 2015-06-16 Kazumasa Iwai , Kiyoto Shibasaki

We investigate the fine structure of magnetic fields in the atmosphere of the quiet Sun. We use photospheric magnetic field measurements from {\sc Sunrise}/IMaX with unprecedented spatial resolution to extrapolate the photospheric magnetic…

Several studies have reported magnetic field fluctuations associated with umbral shock waves. We aim to study the properties and origin of magnetic field fluctuations in the umbral chromosphere. Temporal series of spectropolarimetric…

Solar and Stellar Astrophysics · Physics 2023-08-09 T. Felipe , S. J. González Manrique , C. R. Sangeetha , A. Asensio Ramos

We explore the diagnostic potential of the H$\alpha$ line for probing the chromospheric magnetic field using a realistic 3D radiative magnetohydrodynamic (rMHD) model. The Stokes profiles of the H$\alpha$ line are synthesized through full…

Solar and Stellar Astrophysics · Physics 2025-07-08 Harsh Mathur , Jayant Joshi , Thore Espedal Moe , Tiago M. D. Pereira , K. Nagaraju