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Related papers: A Nanoflare Distribution Generated by Repeated Rel…

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We present the results of 1D hydrodynamic simulations of coronal loops which are subject to nanoflares, caused by either in-situ thermal heating, or non-thermal electrons (NTE) beams. The synthesized intensity and Doppler shifts can be…

Solar and Stellar Astrophysics · Physics 2018-04-18 V. Polito , P. Testa , J. Allred , B. De Pontieu , M. Carlsson , T. M. D. Pereira , M. Gošić , F. Reale

Twisted magnetic flux ropes are reservoirs of free magnetic energy. In a highly-conducting plasma such as the solar corona, energy release through multiple magnetic reconnections can be modelled as a helicity-conserving relaxation to a…

Solar and Stellar Astrophysics · Physics 2023-08-17 Philippa Browning , Mykola Gordovskyy , Alan Hood

Coronal loops form the basic building blocks of the magnetically closed solar corona yet much is still to be determined concerning their possible fine-scale structuring and the rate of heat deposition within them. Using an improved…

Solar and Stellar Astrophysics · Physics 2021-07-07 Thomas Williams , Robert W. Walsh , Stephane Regnier , Craig D. Johnston

Parker (1972) first proposed that coronal heating was the necessary outcome of an energy flux caused by the tangling of coronal magnetic field lines by photospheric flows. In this paper we discuss how this model has been modified by…

Solar and Stellar Astrophysics · Physics 2021-04-07 G. Einaudi , R. B. Dahlburg , I. Ugarte-Urra , J. W. Reep , A. F. Rappazzo , M. Velli

Nanoflares have been proposed as the main source of heating of the solar corona. However, detecting them directly has so far proved elusive, and extrapolating to them from the properties of larger brightenings gives unreliable estimates of…

Astrophysics · Physics 2009-11-11 Anuschka Pauluhn , Sami K. Solanki

The heating of the lower solar corona is examined using numerical simulations and theoretical models of magnetohydrodynamic turbulence in open magnetic regions. A turbulent energy cascade to small length scales perpendicular to the mean…

Astrophysics · Physics 2009-11-07 P. Dmitruk , W. H. Matthaeus , L. J. Milano , S. Oughton , G. P. Zank , D. J. Mullan

Coronal rain consists of cool and dense plasma condensations formed in coronal loops as a result of thermal instability. Previous numerical simulations of thermal instability and coronal rain formation have relied on artificially adding a…

Solar and Stellar Astrophysics · Physics 2020-07-08 P. Kohutova , P. Antolin , A. Popovas , M. Szydlarski , V. H. Hansteen

Kink oscillations of coronal loops, i.e., standing kink waves, is one of the most studied dynamic phenomena in the solar corona. The oscillations are excited by impulsive energy releases, such as low coronal eruptions. Typical periods of…

There is a growing body of evidence that the plasma loops seen with current instrumentation (SOHO, TRACE and Hinode) may consist of many sub-resolution elements or strands. Thus, the overall plasma evolution we observe in these features…

Astrophysics · Physics 2009-11-13 Aveek Sarkar , Robert W Walsh

Coronal loops act as resonant cavities for low frequency fluctuations that are transmitted from the deeper layers of the solar atmosphere and are amplified in the corona, triggering nonlinear interactions. However trapping is not perfect,…

Solar and Stellar Astrophysics · Physics 2015-06-03 Andrea Verdini , Roland Grappin , Marco Velli

The heating of solar coronal loops is at the center of the problem of coronal heating. Given that the origin of the fast solar wind has been tracked down to atmospheric layers with transition region or even chromospheric temperatures, it is…

Solar and Stellar Astrophysics · Physics 2014-06-05 Bo Li , Haixia Xie , Xing Li , Li-Dong Xia

Magnetic flux ropes (MFRs) are thought to be the central structure of solar eruptions, and their ideal MHD instabilities can trigger the eruption. Here we performed a study of all the MFR configurations that lead to major solar flares,…

Solar and Stellar Astrophysics · Physics 2019-11-06 Aiying Duan , Chaowei Jiang , Wen He , Xueshang Feng , Peng Zou , Jun Cui

We aim to study the influence of radiative cooling on the standing kink oscillations of a coronal loop. Using the FLASH code, we solved the 3D ideal magnetohydrodynamic equations. Our model consists of a straight, density enhanced and…

Solar and Stellar Astrophysics · Physics 2015-10-30 N. Magyar , T. Van Doorsselaere , A. Marcu

The high densities, long lifetimes, and narrow emission measure distributions observed in coronal loops with apex temperatures near 1 MK are difficult to reconcile with physical models of the solar atmosphere. It has been proposed that the…

Solar and Stellar Astrophysics · Physics 2010-04-08 Harry P. Warren , David M. Kim , Amanda M. DeGiorgi , Ignacio Ugarte-Urra

The back-reaction of the perturbed thermal equilibrium in the solar corona on compressive perturbations, also known as the effect of wave-induced thermal misbalance, is known to result in thermal instabilities chiefly responsible for the…

Solar and Stellar Astrophysics · Physics 2023-01-24 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Joseph B. Fihosy

Decayless kink oscillations of plasma loops in the solar corona may contain an answer to the enigmatic problem of solar and stellar coronal heating. The polarisation of the oscillations gives us a unique information about their excitation…

One proposed resolution to the long-standing problem of solar coronal heating involves the buildup of magnetic energy in the corona due to turbulent motions at the photosphere that braid the coronal field, and the subsequent release of this…

Solar and Stellar Astrophysics · Physics 2015-05-27 D. I. Pontin , G. Hornig

Local magnetic reversals are an inseparable part of magnetohydrodynamic (MHD) turbulence whose collective outcome on an arbitrary scale in the inertial range may lead to a global stochastic reconnection event with a rate independent of…

High Energy Astrophysical Phenomena · Physics 2021-01-20 Amir Jafari , Ethan Vishniac , Siyao Xu

Recent observations show cool, oscillating prominence threads fading when observed in cool spectral lines and appearing in warm spectral lines. A proposed mechanism to explain this evolution is that the threads were heated by turbulence…

Solar and Stellar Astrophysics · Physics 2020-01-08 Andrew Hillier , Inigo Arregui

Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite…

Solar and Stellar Astrophysics · Physics 2017-01-11 S. Krishna Prasad , D. B. Jess , J. A. Klimchuk , D. Banerjee