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Related papers: An MHD avalanche model of multi-threaded coronal l…

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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

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

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.…

We model the hydrodynamic evolution of the plasma confined in a coronal loop, 30000 km long, subject to the heating of nanoflares due to intermittent magnetic dissipative events in the MHD turbulence produced by loop footpoint motions. We…

Astrophysics · Physics 2009-11-13 F. Reale , G. Nigro , F. Malara , G. Peres , P. Veltri

Observed spectral profiles of emission lines from the corona are found to have widths exceeding the thermal line width. To investigate the physical mechanism, we run a 3D MHD model of a single, straightened loop in which we partially…

Solar and Stellar Astrophysics · Physics 2024-04-02 C. A. Breu , H. Peter , S. K. Solanki , R. Cameron , I. De Moortel

Adopting the MPI-AMRVAC code, we present a 2.5-dimensional magnetohydrodynamic (MHD) simulation, which includes thermal conduction and radiative cooling, to investigate the formation and evolution of the coronal rain phenomenon. We perform…

Solar and Stellar Astrophysics · Physics 2022-03-09 Xiaohong Li , Rony Keppens , Yuhao Zhou

In the quest to solve the long-standing coronal heating problem, it has been suggested half a century ago that coronal loops could be heated by waves. Despite the accumulating observational evidence of the possible importance of coronal…

Solar and Stellar Astrophysics · Physics 2021-02-26 Mijie Shi , Tom Van Doorsselaere , Mingzhe Guo , Konstantinos Karampelas , Bo Li , Patrick Antolin

Aims. The goal is to employ a 3D magnetohydrodynamics (MHD) model including spectral synthesis to model the corona in an observed solar active region. This will allow us to judge the merits of the coronal heating mechanism built into the 3D…

Solar and Stellar Astrophysics · Physics 2017-09-19 Ph. -A. Bourdin , S. Bingert , H. Peter

It was once thought that all coronal loops are in static equilibrium, but observational and modeling developments over the past decade have shown that this is clearly not the case. It is now established that warm (~1 MK) loops observed in…

Solar and Stellar Astrophysics · Physics 2009-04-09 James A. Klimchuk

Coronal jets are the captivating eruptions which are often found in the solar atmosphere, and primarily formed due to magnetic reconnection. Despite their short-lived nature and lower energy compared to many other eruptive events, e.g.…

Solar and Stellar Astrophysics · Physics 2024-09-06 Sushree S Nayak , Samrat Sen , Arpit Kumar Shrivastav , R. Bhattacharyya , P. S. Athiray

Without any doubt solar flaring loops possess a multi-thread internal structure that is poorly resolved and there are no means to observe heating episodes and thermodynamic evolution of the individual threads. These limitations cause…

Solar and Stellar Astrophysics · Physics 2015-11-04 R. Falewicz , P. Rudawy , K. Murawski , A. K. Srivastava

Context: The location of coronal heating in magnetic loops has been the subject of a long-lasting controversy: does it occur mostly at the loop footpoints, at the top, is it random, or is the average profile uniform? Aims: We try to address…

Astrophysics · Physics 2009-11-13 E. Buchlin , P. J. Cargill , S. J. Bradshaw , M. Velli

Quasi-periodic propagating intensity disturbances (PDs) have been observed in large coronal loops in EUV images over a decade, and are widely accepted to be slow magnetosonic waves. However, spectroscopic observations from Hinode/EIS…

Solar and Stellar Astrophysics · Physics 2014-04-24 Tongjiang Wang , Leon Ofman , Joseph M. Davila

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

We investigate the spatial and temporal evolution of the heating of the corona of a cool star such as our Sun in a three-dimensional magneto-hydrodynamic (3D MHD) model. We solve the 3D MHD problem numerically in a box representing part of…

Space Physics · Physics 2015-05-27 Sven Bingert , Hardi Peter

Current analytical and numerical modelling suggest the existence of ubiquitous thin current sheets in the corona that could explain the observed heating requirements. On the other hand, new high resolution observations of the corona…

Solar and Stellar Astrophysics · Physics 2015-06-19 P. Antolin , T. Yokoyama , T. Van Doorsselaere

Context. Photospheric motions shuffle the footpoints of the strong axial magnetic field that threads coronal loops giving rise to turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned…

Solar and Stellar Astrophysics · Physics 2012-08-14 R. B. Dahlburg , G. Einaudi , A. F. Rappazzo , M. Velli

Any successful model of coronal loops must explain a number of observed properties. For warm (~ 1 MK) loops, these include: 1. excess density, 2. flat temperature profile, 3. super-hydrostatic scale height, 4. unstructured intensity…

Solar and Stellar Astrophysics · Physics 2014-11-20 J. A. Klimchuk , J. T. Karpen , S. K. Antiochos

Recent observations of reflected propagating and standing slow-mode waves in hot flaring coronal loops have spurred our investigation into their underlying excitation and damping mechanisms. To understand these processes, we conduct 2.5D…

Solar and Stellar Astrophysics · Physics 2024-04-01 Tongjiang Wang , Leon Ofman , Stephen J. Bradshaw

We review and discuss insights on ideal magnetohydrodynamic (MHD) instabilities that can play a role in destabilizing solar coronal flux rope structures. For single flux ropes, failed or actual eruptions may result from internal or external…

Solar and Stellar Astrophysics · Physics 2019-10-29 Rony Keppens , Yang Guo , Kirit Makwana , Zhixing Mei , Bart Ripperda , Chun Xia , Xiaozhou Zhao