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Related papers: Solar coronal heating from small-scale magnetic br…

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The perplexing mystery of what maintains the solar coronal temperature at about a million K, while the visible disc of the Sun is only at 5800 K, has been a long standing problem in solar physics. A recent study by Mondal(2020) has provided…

Solar and Stellar Astrophysics · Physics 2024-02-09 Shabbir Bawaji , Ujjaini Alam , Surajit Mondal , Divya Oberoi

We simulate several magnetic reconnection processes in the low solar chromosphere/photosphere, the radiation cooling, heat conduction and ambipolar diffusion are all included. Our numerical results indicate that both the high temperature($…

Solar and Stellar Astrophysics · Physics 2016-12-14 Lei Ni , Jun Lin , Ilia I. Roussev , Brigitte Schmieder

In this paper we further develop a model for the heating of coronal loops by Alfven wave turbulence (AWT). The Alfven waves are assumed to be launched from a collection of kilogauss flux tubes in the photosphere at the two ends of the loop.…

Solar and Stellar Astrophysics · Physics 2017-11-08 Adriaan A. van Ballegooijen , Mahboubeh Asgari-Targhi , Alexander Voss

Context: Transverse loop oscillations and loop contractions are commonly associated with solar flares, but the two types of motion have traditionally been regarded as separate phenomena. Aims: We present an observation of coronal loops…

Solar and Stellar Astrophysics · Physics 2015-08-26 Alexander J. B. Russell , Paulos J. A. Simoes , Lyndsay Fletcher

Coronal loop oscillations are common phenomena in the solar corona, which are often classified as decaying and decayless oscillations. Using the high-resolution observation measured by the Extreme Ultraviolet Imager (EUI) onboard the Solar…

Solar and Stellar Astrophysics · Physics 2023-02-15 Dong Li , David M. Long

Coronal active regions are observed to get fuzzier and fuzzier (i.e. more and more confused and uniform) in harder and harder energy bands or lines. We explain this evidence as due to the fine multi-temperature structure of coronal loops.…

Solar and Stellar Astrophysics · Physics 2015-05-19 Massimiliano Guarrasi , Fabio Reale , Giovanni Peres

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

It has been proposed that particles bouncing between magnetized flows converging in a reconnection region can be accelerated by the first order Fermi mechanism. Analytical considerations of this mechanism have shown that the spectral index…

Space Physics · Physics 2016-07-06 Elena Provornikova , John Martin Laming , Vyacheslav S. Lukin

Recent progress in obtaining high spatial resolution images of the solar corona in the extreme-ultraviolet (EUV) with Hinode, TRACE, SDO and recent Hi-C missions and soft X-ray (SXR) bands opened a new avenue in understanding the solar…

Solar and Stellar Astrophysics · Physics 2014-09-16 V. S. Airapetian , J. Allred

Poynting flux generated by random shuffling of photospheric magnetic footpoints is transferred through the upper atmosphere of the Sun where the plasma is heated to over 1 MK in the corona. High spatiotemporal resolution observations of the…

Solar and Stellar Astrophysics · Physics 2024-11-20 L. P. Chitta , M. van Noort , H. N. Smitha , E. R. Priest , L. H. M. Rouppe van der Voort

Where particle acceleration and plasma heating take place in relation to magnetic reconnection is a fundamental question for solar flares. We report analysis of an M7.7 flare on 2012 July 19 observed by SDO/AIA and RHESSI. Bi-directional…

Solar and Stellar Astrophysics · Physics 2014-04-04 Wei Liu , Qingrong Chen , Vahe' Petrosian

Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar…

Solar and Stellar Astrophysics · Physics 2023-07-19 Paola Testa , Steve Saar , Jeremy Drake

One of the mechanisms proposed for heating the corona above solar active regions is the damping of magnetohydrodynamic (MHD) waves. Continuing on previous work, we provide observational evidence for the existence of high-frequency MHD waves…

Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed…

Solar and Stellar Astrophysics · Physics 2015-05-14 Steven R. Cranmer

How the solar corona is heated to high temperatures remains an unsolved mystery in solar physics. In the present study we analyse observations of 50 whole active-region loops taken with the Extreme-ultraviolet Imaging Spectrometer (EIS) on…

Solar and Stellar Astrophysics · Physics 2017-06-28 Haixia Xie , Maria S. Madjarska , Bo Li , Zhenghua Huang , Lidong Xia , Thomas Wiegelmann , Hui Fu , Chaozhou Mou

The observed solar activity is believed to be driven by the dissipation of nonpotential magnetic energy injected into the corona by dynamic processes in the photosphere. The enormous range of scales involved in the interaction makes it…

Solar and Stellar Astrophysics · Physics 2015-06-12 Vadim M. Uritsky , Joseph M. Davila , Leon Ofman , Aaron J. Coyner

Coronal loops interconnecting two active regions, called as interconnecting loops (ILs), are prominent large-scale structures in the solar atmosphere. They carry a significant amount of magnetic flux, therefore are considered to be an…

Solar and Stellar Astrophysics · Physics 2018-06-27 Guohui Du , Yao Chen , Chunming Zhu , Chang Liu , Lili Ge , Bing Wang , Chuanyang Li , Haimin Wang

Decayless kink oscillations are omnipresent in the solar atmosphere and a viable candidate for coronal heating. Though there have been extensive studies of decayless oscillations in coronal loops with a few hundred Mm lengths, the…

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

Understanding the relationship between the magnetic field and coronal heating is one of the central problems of solar physics. However, studies of the magnetic properties of impulsively heated loops have been rare. We present results from a…

Solar and Stellar Astrophysics · Physics 2019-06-12 Ignacio Ugarte-Urra , Nicholas A. Crump , Harry P. Warren , Thomas Wiegelmann