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Related papers: Dynamics of the solar chromosphere. V. High-freque…

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Understanding the evolution of the complex magnetic fields found in solar active regions is an active area of research. There are numerous models for such fields which range in their complexity due to the number of known physical effects…

Solar and Stellar Astrophysics · Physics 2025-02-26 Oliver Rice , Christopher Prior

We establish a spherically symmetric model of solar atmosphere, which consists of the whole chromosphere and low corona below the $1.25$ solar radius. It is a hydrodynamic model with heating in the chromosphere through an artificial energy…

Solar and Stellar Astrophysics · Physics 2025-03-13 Li Xue , Cheng-Liang Jiao , Li-Xin Zhang

Plage regions are patches of concentrated magnetic field in the Sun's atmosphere where hot coronal loops are rooted. While previous studies have shed light on the properties of plage magnetic fields in the photosphere, there are still…

Solar and Stellar Astrophysics · Physics 2023-08-23 J. M. da Silva Santos , K. Reardon , G. Cauzzi , T. Schad , V. Martinez Pillet , A. Tritschler , F. Wöger , R. Hofmann , J. Stauffer , H. Uitenbroek

We investigate high resolution spectroscopic and imaging observations from the CRisp Imaging SpectroPolarimeter (CRISP) instrument to study the dynamics of chromospheric spicule type events. It is widely accepted that chromospheric fine…

Solar and Stellar Astrophysics · Physics 2021-12-30 Juie Shetye , Erwin Verwichte , Marco Stangalini , J. G. Doyle

The presence of intense magnetic fields in and around sunspots is expected to modify the solar structure and oscillation frequencies. Applying the ring diagram technique to data from the Michelson Doppler Imager (MDI) on board the Solar and…

Astrophysics · Physics 2009-11-07 S. P. Rajaguru , Sarbani Basu , H. M. Antia

We found that oscillations of LOS velocity in H-alpha are different for various parts of faculae regions. Power spectra show that the contribution of low-frequency modes (1.2 - 2 mHz) increase at the network boundaries. Three and five-…

Solar and Stellar Astrophysics · Physics 2011-10-10 N. I. Kobanov , V. A. Pulyaev

Context. The solar chromosphere is the interface between the solar surface and the solar corona. Modelling of this region is difficult because it represents the transition from optically thick to thin radiation escape, from gas-pressure…

Solar and Stellar Astrophysics · Physics 2015-12-09 Mats Carlsson , Viggo H. Hansteen , Boris V. Gudiksen , Jorrit Leenaarts , Bart De Pontieu

Context. MHD waves are proposed to transport sufficient energy from the photosphere to heat the transition-region (TR) and corona. However, various aspects of these waves such as their nature, propagation characteristics and role in the…

Solar and Stellar Astrophysics · Physics 2020-02-12 P. Kayshap , A. K. Srivastava , S. K. Tiwari , P. Jelinek , M. Mathioudakis

On 2008 January 10, the twin Solar Terrestrial Relations Observatory (STEREO) A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme UltraViolet Imager (EUVI) instruments with the aim of investigating…

Solar and Stellar Astrophysics · Physics 2010-01-15 M. S. Marsh , R. W. Walsh , S. Plunkett

High resolution spectral observations of the lower solar atmosphere (chromosphere and transition region) during coronal heating events, in combination with predictions from models of impulsively heated loops, provide powerful diagnostics of…

Solar and Stellar Astrophysics · Physics 2023-11-01 Paola Testa , Helle Bakke , Luc Rouppe van der Voort , Bart De Pontieu

The quiet solar corona emits meter-wave thermal bremsstrahlung. Coronal radio emission can only propagate above that radius, $R_\omega$, where the local plasma frequency eqals the observing frequency. The radio interferometer LOw Frequency…

Solar and Stellar Astrophysics · Physics 2018-06-13 C. Vocks , G. Mann , F. Breitling , M. M. Bisi , B. Dabrowski , R. Fallows , P. T. Gallagher , A. Krankowski , J. Magdalenic , C. Marque , D. Morosan , H. Rucker

Aims. To investigate the role of acoustic and magneto-acoustic waves in heating the solar chromosphere, observations in strong chromospheric lines are analyzed by comparing the deposited acoustic-energy flux with the total integrated…

Solar and Stellar Astrophysics · Physics 2020-10-07 V. Abbasvand , M. Sobotka , M. Švanda , P. Heinzel , Marta García Rivas , C. Denker , H. Balthasar , M. Verma , I. Kontogiannis , J. Koza , D. Korda , C. Kuckein

We present simultaneous X-ray and spectral ultraviolet (UV) observations of strikingly-coherent oscillations in emission from a coronal looptop and fan structure, during the impulsive phase of a long-duration M-class solar flare. The 50 s…

Solar and Stellar Astrophysics · Physics 2024-11-06 Ryan J. French , Laura A. Hayes , Maria D. Kazachenko , Katharine K. Reeves , Chengcai Shen , Juraj Lörinčík

In this work we use solar observations with the ALMA radio telescope at the wavelength of 1.21 mm. The aim of the analysis is to improve understanding of the solar chromosphere, a dynamic layer in the solar atmosphere between the…

Solar and Stellar Astrophysics · Physics 2018-12-19 R. Brajša , D. Sudar , I. Skokic , A. O. Benz , M. Kuhar , A. Kobelski , S. Wedemeyer , S. M. White , H. -G. Ludwig , M. Temmer , S. H. Saar , C. L. Selhorst

New observational facilities are beginning to enable insights into the three-dimensional (3D) nature of exoplanets. Transmission spectroscopy is the most widely used method for characterizing transiting temperate exoplanet's atmospheres,…

Earth and Planetary Astrophysics · Physics 2025-04-24 Nicholas Scarsdale , C. E. Harman , Thomas J. Fauchez

In the solar atmosphere, Alfv\'en waves are believed to play an important role in the transfer of energy from the photosphere to the corona and solar wind, and in the heating of the chromosphere. We perform numerical computations to…

Solar and Stellar Astrophysics · Physics 2019-01-23 Roberto Soler , Jaume Terradas , Ramon Oliver , Jose Luis Ballester

We investigate the scaling properties of the long-range temporal evolution and intermittency of SDO/AIA intensity observations in four solar environments: an active region core, a weak emission region, and two core loops. We use two…

Solar and Stellar Astrophysics · Physics 2016-11-15 Ana Cristina Cadavid , Yeimy J. Rivera , John K. Lawrence , Damian J. Christian , Peter J. Jennings , A. Franco Rappazzo

Solar pores are strongly magnetized regions lacking a photospheric penumbra and characterized by predominantly vertical magnetic fields. We present a multi-line study of flashes in a solar pore using high-resolution observations from the…

Solar and Stellar Astrophysics · Physics 2026-02-11 Sandeep Dubey , Christian Beck , Rahul Yadav , Tobias Felipe , Shibu K Mathew

Low-frequency longitudinal oscillations of a flaring coronal loop are studied numerically. In the recent work of Nakariakov et al., Astron. and Astrophys., 414, L25-L28 (2004) it has been shown that the time dependences of density and…

Astrophysics · Physics 2009-11-10 D. Tsiklauri , V. M. Nakariakov , T. D. Arber , M. J. Aschwanden

Inhomogeneities in wave propagation conditions near and below the solar surface have been detected by means of time-distance helioseismology. Here we calculate the effect of temperature inhomogeneities on the travel times of sound waves. A…

Astrophysics · Physics 2015-06-24 M. Brüggen , H. C. Spruit