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Related papers: Disentangling flows in the solar transition region

200 papers

There is evidence for coronal plasma flows to break down into fragments and to be laminar. We investigate this effect by modeling flows confined along magnetic channels. We consider a full MHD model of a solar atmosphere box with a dipole…

Solar and Stellar Astrophysics · Physics 2017-12-27 A. Petralia , F. Reale , P. Testa

Coronal loops are the basic structures of the solar transition region and corona. The understanding of physical mechanism behind the loop heating, plasma flows, and filling are still considered a major challenge in the solar physics. The…

Solar and Stellar Astrophysics · Physics 2015-02-24 G. R. Gupta , Durgesh Tripathi , Helen E. Mason

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

The Parker or field line tangling model of coronal heating is studied comprehensively via long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics…

Astrophysics · Physics 2009-12-06 A. F. Rappazzo , M. Velli , G. Einaudi , R. B. Dahlburg

In the solar corona, several mechanisms of the drift wave instability can make the mode growing up to amplitudes at which particle acceleration and stochastic heating by the drift wave take place. The stochastic heating, well known from…

Solar and Stellar Astrophysics · Physics 2015-05-19 J. Vranjes , S. Poedts

An expansion of cross-sectional area directly impacts the mass flow along a coronal loop, and significantly alters the radiative and hydrodynamic evolution of that loop as a result. Previous studies have found that an area expansion from…

Solar and Stellar Astrophysics · Physics 2024-03-20 Jeffrey W. Reep , Roger B. Scott , Sherry Chhabra , John Unverferth , Kalman J. Knizhnik

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

Observations suggest a power-law relation between the coronal emission in X-rays, $L_{\rm{X}}$, and the total (unsigned) magnetic flux at the stellar surface, $\Phi$. The physics basis for this relation is poorly understood. We use…

Solar and Stellar Astrophysics · Physics 2021-08-04 J. Zhuleku , J. Warnecke , H. Peter

With the adaptation of the FLASH code we simulate magnetohydrodynamic-gravity waves and vortices as well as their response in the magnetized three-dimensional (3D) solar atmosphere at different heights to understand the localized energy…

Solar and Stellar Astrophysics · Physics 2015-06-17 K. Murawski , I. Ballai , A. K. Srivastava , D. Lee

Context. The structure and heating of coronal loops are investigated since decades. Established scaling laws relate fundamental quantities like the loop apex temperature, pressure, length, and the coronal heating. Aims. We test such scaling…

Solar and Stellar Astrophysics · Physics 2017-09-19 Philippe-A. Bourdin , Sven Bingert , Hardi Peter

A model is presented for generation of fast solar wind in coronal holes, relying on heating that is dominated by turbulent dissipation of MHD fluctuations transported upwards in the solar atmosphere. Scale-separated transport equations…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Verdini , M. Velli , W. H. Matthaeus , S. Oughton , P. Dmitruk

Magnetic reconnection in the corona results in contracting flare loops, releasing energy into plasma heating and shocks. The hydrodynamic shocks so produced drive thermal conduction fronts (TCFs) which transport energy into the chromosphere…

Solar and Stellar Astrophysics · Physics 2015-06-22 Sean Brannon , Dana Longcope

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

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

A hot corona is suggested to be above the standard thin disk. The anisotropy of hard X-ray emission in radio-quiet active galactic nuclei implies that the corona is not static and probably moves outwards like winds. We perform…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Xiao-Hong Yang , De-Fu Bu , Qi-Xiu Li

We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. We analyse a 3D MHD…

Solar and Stellar Astrophysics · Physics 2017-12-05 Jörn Warnecke , Feng Chen , Sven Bingert , Hardi Peter

Current models of the solar wind must approximate (or ignore) the small-scale dynamics within the solar atmosphere, however these are likely important in shaping the emerging wave-turbulence spectrum and ultimately heating/accelerating the…

Solar and Stellar Astrophysics · Physics 2022-09-28 Adam J. Finley , Sacha A. Brun , Mats Carlsson , Mikolaj Szydlarski , Viggo Hansteen , Munehito Shoda

Shocks are often invoked as heating mechanisms in astrophysical systems, with both adiabatic compression and dissipative heating that leading to temperature increases. Whilst shocks are reasonably well understood for ideal…

Solar and Stellar Astrophysics · Physics 2024-01-03 Ben Snow

Rapidly decaying slow magnetoacoustic waves are regularly observed in the solar coronal structures, offering a promising tool for a seismological diagnostics of the coronal plasma, including its thermodynamical properties. The effect of…

Solar and Stellar Astrophysics · Physics 2019-08-21 D. Y. Kolotkov , V. M. Nakariakov , D. I. Zavershinskii

Coronal loops trace out bipolar, arch-like magnetic fields above the Sun's surface. Recent measurements that combine rotational tomography, extreme ultraviolet imaging, and potential-field extrapolation have shown the existence of large…

Solar and Stellar Astrophysics · Physics 2016-11-15 Avery J. Schiff , Steven R. Cranmer
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