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Related papers: Modeling a coronal loop heated by MHD-turbulence n…

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Nanoflares, which are consequences of braids in tangled magnetic fields, are an important candidate to heat the solar corona to million degrees. However, their observational evidence is sparse and many of their observational characteristics…

Solar and Stellar Astrophysics · Physics 2025-04-18 Xiuhui Zuo , Zhenghua Huang , Hengyuan Wei , Chao Zhang , Boyu Sun , Youqian Qi , Hui Fu , Weixin Liu , Mingzhe Sun , Ming Xiong , Lidong Xia

In this work we study the process of energy dissipation triggered by a slow large scale motion of a magnetized conducting fluid. Our consideration is motivated by the problem of heating the solar corona, which is believed to be governed by…

Solar and Stellar Astrophysics · Physics 2015-10-14 P. Pongkitiwanichakul , F. Cattaneo , S. Boldyrev , J. Mason , J. C. Perez

The Parker or field line tangling model of coronal heating is investigated through long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics (RMHD).…

Solar and Stellar Astrophysics · Physics 2010-02-15 A. F. Rappazzo , M. Velli , G. Einaudi

We present the results of models of impulsively heated coronal loops using the 1-D hydrodynamic Adaptively Refined Godunov Solver (ARGOS) code. The impulsive heating events (which we refer to as "nanoflares") are modeled by discrete pulses…

Solar and Stellar Astrophysics · Physics 2025-09-01 Therese A. Kucera , James A. Klimchuk , Manuel Luna

We analyze a 96 ks Chandra/HETGS observation of the single G-type giant HR 9024. The high flux allows us to examine spectral line and continuum diagnostics at high temporal resolution, to derive plasma parameters. A time-dependent 1D…

Astrophysics · Physics 2011-02-11 Paola Testa , Fabio Reale , David Garcia-Alvarez , David P. Huenemoerder

We present a series of numerical simulations aimed at understanding the nature and origin of turbulence in coronal loops in the framework of the Parker model for coronal heating. A coronal loop is studied via reduced magnetohydrodynamics…

Solar and Stellar Astrophysics · Physics 2015-03-13 A. F. Rappazzo , M. Velli , G. Einaudi

Context: It is thought likely that vast numbers of nanoflares are responsible for the corona having a temperature of millions of degrees. Current observational technologies lack the resolving power to confirm the nanoflare hypothesis. An…

Solar and Stellar Astrophysics · Physics 2015-05-19 Michael R. Bareford , Philippa. K. Browning , Ronald A. M. Van der Linden

MHD turbulence has long been proposed as a mechanism for the heating of coronal loops in the framework of the Parker scenario for coronal heating. So far most of the studies have focused on its dynamical properties without considering its…

Solar and Stellar Astrophysics · Physics 2014-11-20 R. B. Dahlburg , A. F. Rappazzo , M. Velli

We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a…

Solar and Stellar Astrophysics · Physics 2014-05-08 F. Chen , H. Peter , S. Bingert , M. C. M. Cheung

Standing long-period (with the periods longer than several minutes) oscillations in large hot (with the temperature higher than 3 MK) coronal loops have been observed as the quasi-periodic modulation of the EUV and microwave intensity…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sanjay Kumar , V. M. Nakariakov , Y. -J. Moon

Coronal flare emission is commonly observed to decay on timescales longer than those predicted by impulsively-driven, one-dimensional flare loop models. This discrepancy is most apparent during the gradual phase, where emission from these…

Solar and Stellar Astrophysics · Physics 2023-03-01 William Ashfield , Dana Longcope

Advanced 3D radiative MHD simulations now reproduce many properties of the outer solar atmosphere. When including a domain from the convection zone into the corona, a hot chromosphere and corona are self-consistently maintained. Here we…

Solar and Stellar Astrophysics · Physics 2015-10-07 Viggo Hansteen , Nuno Guerreiro , Bart De Pontieu , Mats Carlsson

All theories that attempt to explain the heating of the high temperature plasma observed in the solar corona are based on short bursts of energy. The intensities and velocities measured in the cores of quiescent active regions, however, can…

Solar and Stellar Astrophysics · Physics 2015-06-05 Fana M. Mulu-Moore , Amy R. Winebarger , Harry P. Warren

Transverse MHD waves permeate the solar atmosphere and are a candidate for coronal heating. However, the origin of these waves is still unclear. In this work, we analyse coordinated observations from \textit{Hinode}/SOT and \textit{IRIS} of…

Solar and Stellar Astrophysics · Physics 2018-07-25 Patrick Antolin , Paolo Pagano , Ineke De Moortel , Valery M. Nakariakov

Long-lasting, intense, stellar X-ray flares may approach conditions of breaking magnetic confinement and evolving in open space. We explore this hypothesis with hydrodynamic simulations of flares occurring in a non-confined corona: model…

Astrophysics · Physics 2009-11-07 F. Reale , F. Bocchino , G. Peres

We analyzed a coronal loop observed with the Normal Incidence Spectrometer (NIS), which is part of the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO). The measured Doppler shifts and proper…

Astrophysics · Physics 2009-11-10 C. Gontikakis , G. J. D. Petrie , H. C. Dara , K. Tsinganos

A possible key element for large-scale energy release in the solar corona is an MHD kink instability in a single twisted magnetic flux tube. An initial helical current sheet fragments in a turbulent way into smaller-scale sheets, similarly…

Solar and Stellar Astrophysics · Physics 2023-10-04 G. Cozzo , J. Reid , P. Pagano , F. Reale , A. W. Hood

We study the propagation properties of slow magneto-acoustic waves in a multi-thermal coronal loop using a 3D MHD model, for the first time. A bundle of 33 vertical cylinders, each of 100{\,}km radius, randomly distributed over a circular…

Solar and Stellar Astrophysics · Physics 2024-06-06 S. Krishna Prasad , T. Van Doorsselaere

The physical processes causing energy exchange between the Sun's hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that…

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