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Related papers: Multi-Stranded Coronal Loops: Quantifying Strand N…

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We study the signatures of different coronal heating regimes on the differential emission measure (DEM) of multi-stranded coronal loops by means of hydrodynamic simulations. We consider heating either uniformly distributed along the loops…

Solar and Stellar Astrophysics · Physics 2014-11-20 R. Susino , A. C. Lanzafame , A. F. Lanza , D. Spadaro

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

A well known behavior of EUV light curves of discrete coronal loops is that the peak intensities of cooler channels or spectral lines are reached at progressively later times than hotter channels. This time lag is understood to be the…

Solar and Stellar Astrophysics · Physics 2015-06-04 Nicholeen M. Viall , James A. Klimchuk , NASA Goddard Space Flight Center

In solar coronal loops, thermal non-equilibrium (TNE) is a phenomenon that can occur when the heating is both highly-stratified and quasi-constant. Unambiguous observational identification of TNE would thus permit to strongly constrain…

Solar and Stellar Astrophysics · Physics 2017-02-08 Clara Froment , Frédéric Auchère , Guillaume Aulanier , Zoran Mikić , Karine Bocchialini , Eric Buchlin , Jacques Solomon

The heating of the solar corona is one of the big questions in astrophysics. Rapid pulses called nanoflares are among the best candidate mechanisms. The analysis of the time variability of coronal X-ray emission is potentially a very useful…

Solar and Stellar Astrophysics · Physics 2012-01-27 S. Terzo , F. Reale , M. Miceli , R. Kano , S. Tsuneta , J. A. Klimchuk

Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The…

Thermal non-equilibrium (TNE) is a phenomenon that can occur in solar coronal loops when the heating is quasi-constant and highly-stratified. Under such heating conditions, coronal loops undergo cycles of evaporation and condensation. The…

Solar and Stellar Astrophysics · Physics 2019-12-25 C. Froment , P. Antolin , V. M. J. Henriques , P. Kohutova , L. H. M. Rouppe van der Voort

Coronal loops are building blocks of solar active regions. However, their formation mechanism is still not well understood. Here we present direct observational evidence for the formation of coronal loops through magnetic reconnection as…

Solar and Stellar Astrophysics · Physics 2021-07-14 Zhenyong Hou , Hui Tian , Hechao Chen , Xiaoshuai Zhu , Zhenghua Huang , Xianyong Bai , Jiansen He , Yongliang Song , Lidong Xia

We report preliminary results from a series of numerical simulations of the reduced magnetohydrodynamic equations, used to describe the dynamics of magnetic loops in active regions of the solar corona. A stationary velocity field is applied…

Astrophysics · Physics 2009-10-31 Pablo Dmitruk , Daniel Gomez

A model interpreting variations of EUV brightness upward propagating in solar coronal loops as slow magnetoacoustic waves is developed. A loop is considered to have a non-zero plane inclination angle and offset of circular loop centre from…

Astrophysics · Physics 2009-11-07 D. Tsiklauri , V. M. Nakariakov

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

The existence of the million-degree corona above the cooler photosphere is an unsolved problem in astrophysics. Detailed study of quiescent corona that exists regardless of the phase of the solar cycle may provide fruitful hints towards…

Solar and Stellar Astrophysics · Physics 2022-12-07 Vishal Upendran , Durgesh Tripathi , N. P. S. Mithun , Santosh Vadawale , Anil Bhardwaj

There is evidence that coronal heating is highly intermittent, and flares are the high energy extreme. The properties of the heat pulses are difficult to constrain. Here hydrodynamic loop modeling shows that several large amplitude…

Solar and Stellar Astrophysics · Physics 2016-08-03 F. Reale

The brightness of the emission from coronal loops in the solar atmosphere is strongly dependent on the temperature and density of the confined plasma. After a release of energy, these loops undergo a heating and upflow phase, followed by a…

Solar and Stellar Astrophysics · Physics 2019-03-20 C. D. Johnston , S. J. Bradshaw

The quiet solar corona consists of myriads of loop-like features, with magnetic fields originating from network and internetwork regions on the solar surface. The continuous interaction between these different magnetic patches leads to…

Solar and Stellar Astrophysics · Physics 2021-04-13 L. P. Chitta , H. Peter , P. R. Young

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

Coronal loops are the basic building block of the upper solar atmosphere. Comprehending how these are energized, structured, and evolve is key to understanding stellar coronae. Here we investigate how the energy to heat the loop is…

Solar and Stellar Astrophysics · Physics 2022-02-09 C. Breu , H. Peter , R. Cameron , S. K. Solanki , D. Przybylski , M. Rempel , L. P. Chitta

All three components of the current density are required to compute the heating rate due to free magnetic energy dissipation. Here we present a first test of a new model developed to determine if the times of increases in the resistive…

Solar and Stellar Astrophysics · Physics 2020-04-29 Michael L. Goodman , Chiman Kwan , Bulent Ayhan , Eric L. Shang

The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that…

Solar and Stellar Astrophysics · Physics 2015-05-28 Amy Winebarger , Joan Schmelz , Harry Warren , Steve Saar , Vinay Kashyap

A detailed analysis of a coronal loop oscillation event is presented, using data from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) for the first time. The loop oscillation event occurred on 2010 Oct…

Solar and Stellar Astrophysics · Physics 2015-05-28 Markus J. Aschwanden , Carolus J. Schrijver