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A large part of the hot corona consists of magnetically confined, bright plasma loops. These observed loops are in turn structured into bright strands. We investigate the relationship between magnetic field geometry, plasma properties and…

Solar and Stellar Astrophysics · Physics 2025-12-22 C. A. Breu , D. I. Pontin , E. Priest , I. De Moortel

A new mechanism to form a magnetic pressure supported, high temperature corona above the photosphere of an accretion disk is explored using three dimensional radiation magneto-hydrodynamic (MHD) simulations. The thermal properties of the…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Yan-Fei Jiang , James M. Stone , Shane W. Davis

A three-dimensional MHD model for the propagation and dissipation of Alfven waves in a coronal loop is developed. The model includes the lower atmospheres at the two ends of the loop. The waves originate on small spatial scales (less than…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. A. van Ballegooijen , M. Asgari-Targhi , S. R. Cranmer , E. E. DeLuca

Magnetohydrodynamic (MHD) waves are candidates for heating the solar chromosphere, although it is still unclear which mode of the wave is dominant in heating. We perform two-dimensional radiative MHD simulation to investigate the…

Solar and Stellar Astrophysics · Physics 2021-08-04 Yikang Wang , Takaaki Yokoyama , Haruhisa Iijima

The presence of magnetic field is crucial in the transport of energy through the solar atmosphere. Recent ground-based and space-borne observations of the quiet Sun have revealed that magnetic field accumulates at photospheric heights, via…

Solar and Stellar Astrophysics · Physics 2019-06-19 Juan Martínez-Sykora , Viggo H. Hansteen , Boris Gudiksen , Mats Carlsson , Bart De Pontieu , Milan Gosic

aims: We aim to provide an estimate of the minimum temperature of the quiet solar chromosphere. methods: We perform a 2D radiation-MHD simulation spanning the upper convection zone to the lower corona. The simulation includes non-LTE…

Solar and Stellar Astrophysics · Physics 2015-05-28 Jorrit Leenaarts , Mats Carlsson , Viggo Hansteen , Boris V. Gudiksen

Identifying the heating mechanisms of the solar corona and the driving mechanisms of solar wind are key challenges in understanding solar physics. A full three-dimensional compressible magnetohydrodynamic (MHD) simulation was conducted to…

Solar and Stellar Astrophysics · Physics 2020-11-25 Takuma Matsumoto

The heating of the solar corona and the puzzle of the slender high reaching magnetic loops seen in observations from the Transition Region And Coronal Explorer(TRACE) has been investigated through 3D numerical simulations, and found to be…

Astrophysics · Physics 2007-05-23 Boris V. Gudiksen , Aake Nordlund

The nanoflare paradigm of coronal heating has proven extremely promising for explaining the presence of hot, multi-million degree loops in the solar corona. In this paradigm, localized heating events supply enough energy to heat the solar…

Solar and Stellar Astrophysics · Physics 2020-09-02 Kalman J. Knizhnik , Will T. Barnes , Jeffrey W. Reep , Vadim M. Uritsky

We present a new global model of the solar corona, including the low corona, the transition region and the top of chromosphere. The realistic 3D magnetic field is simulated using the data from the photospheric magnetic field measurements.…

It remains unclear which physical processes are responsible for the dramatic increase with height of the temperature in stellar atmospheres, known as the chromospheric ($\sim$10,000 K) and coronal (several million K) heating problems.…

Solar and Stellar Astrophysics · Physics 2022-11-17 Souvik Bose , Bart De Pontieu , Viggo Hansteen , Alberto Sainz Dalda , Sabrina Savage , Amy Winebarger

The mechanism behind coronal heating still elude direct observation and modelling of viable theoretical processes and the subsequent effect on coronal structures is one of the key tools available to assess possible heating mechanisms.…

Solar and Stellar Astrophysics · Physics 2020-11-11 P. Pagano , I. De Moortel , R. J. Morton

The Sun's magnetic field is a key driver in coronal heating and consequently solar wind acceleration. Remote measurement of the photosphere provides the magnetic surface boundary condition necessary for data-constrained 3D global coronal…

Solar and Stellar Astrophysics · Physics 2025-11-06 Caroline L. Evans , Cooper Downs , Donald Schmit

The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. Peter , S. Bingert

Long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry are carried out, within the framework of reduced magnetohydrodynamics (RMHD), to understand coronal heating driven by motion of field lines…

Astrophysics · Physics 2008-11-26 A. F. Rappazzo , M. Velli , G. Einaudi , R. B. Dahlburg

Aims: We study the differences between non-magnetic and magnetic regions in the flow and thermal structure of the upper solar photosphere. Methods: Radiative MHD simulations representing a quiet region and a plage region, respectively,…

Solar and Stellar Astrophysics · Physics 2015-06-03 R. Moll , R. H. Cameron , M. Schüssler

Microflares, one of small-scale solar activities, are believed to be caused by magnetic reconnection. Nevertheless, their three-dimensional (3D) magnetic structures, thermodynamic structures, and physical links to the reconnection have been…

Solar and Stellar Astrophysics · Physics 2022-05-18 Z. F. Li , X. Cheng , F. Chen , J. Chen , M. D. Ding

We present an ab initio approach to the solar coronal heating problem by modelling a small part of the solar corona in a computational box using a 3D MHD code including realistic physics. The observed solar granular velocity pattern and its…

Astrophysics · Physics 2009-11-10 B. V. Gudiksen , Å. Nordlund

The chromosphere of the quiet Sun is a highly intermittent and dynamic phenomenon. Three-dimensional radiation (magneto-)hydrodynamic simulations exhibit a mesh-like pattern of hot shock fronts and cool expanding post-shock regions in the…

Astrophysics · Physics 2009-11-13 Sven Wedemeyer-Böhm , Friedrich Wöger

It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…

Solar and Stellar Astrophysics · Physics 2022-11-02 James A. Klimchuk , Kalman J. Knizhnik , Vadim M. Uritsky