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Related papers: Solar Coronal Loops Resolved by Hinode and SDO

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We investigate numerically the time evolution of velocity and magnetic field fluctuations in a coronal loop, focusing on the dynamics due to both phase mixing and turbulent cascade. The intensity, doppler velocity and non-thermal broadening…

Cool stars like our Sun are surrounded by a million degree hot outer atmosphere, the corona. Since more than 60 years the physical nature of the processes heating the corona to temperatures well in excess of those on the stellar surface…

Astrophysics · Physics 2009-11-10 H. Peter , B. V. Gudiksen , A. Nordlund

Nanoflares are impulsive energy releases by magnetic reconnection in the braided coronal magnetic field, which is a potential mechanism for heating the corona. However, there are still sporadic observations of the interchange of braiding…

Solar and Stellar Astrophysics · Physics 2023-11-01 Y. Bi , J. J. Yang , Y. Qin , Z. P. Qiang , J. C. Hong , B. Yang , Z. Xu , H. Liu , K. F. Ji

The solar coronal heating problem is an open question since 1939. One proposed model for the transport and release of mechanical energy generated in the sub-phorospheric layers and photosphere is the nanoflare model that incorporates Ohmic…

Solar and Stellar Astrophysics · Physics 2017-07-12 Charalambos Kanella , Boris V. Gudiksen

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

Context. The He i 1083 nm is a powerful diagnostic for inferring properties of the upper solar chromosphere, in particular for the magnetic field. The basic formation of the line in one-dimensional models is well understood, but the…

Solar and Stellar Astrophysics · Physics 2016-10-19 Jorrit Leenaarts , Thomas Golding , Mats Carlsson , Tine Libbrecht , Jayant Joshi

Solar Coronal Heating is a Nonlinear Quantum Mechanical Phenomenon. Corona is a powerful source of X-rays and ionisations & emissions of such radiations are quantum mechanical and levels are highly unstable to order of femto-seconds. A…

Solar and Stellar Astrophysics · Physics 2019-03-28 Antony Soosaleon

EUV observations of warm coronal loops suggest that they are bundles of unresolved strands that are heated impulsively to high temperatures by nanoflares. The plasma would then have the observed properties (e.g., excess density compared to…

Solar and Stellar Astrophysics · Physics 2011-02-11 S. Patsourakos , J. A. Klimchuk

Coronal loops, seen in solar coronal images, are believed to represent emission from magnetic flux tubes with compact cross-sections. We examine the 3D structure of plasma above an active region in a radiative magnetohydrodynamic simulation…

Solar and Stellar Astrophysics · Physics 2022-03-09 A. Malanushenko , M. C. M. Cheung , C. E. DeForest , J. A. Klimchuk , M. Rempel

Recent coronal loop modeling has emphasized the importance of combining both Coulomb collisions and turbulent scattering to characterize field-aligned thermal conduction, which invokes a hybrid loop model. In this work we generalize the…

Solar and Stellar Astrophysics · Physics 2024-03-05 Y. Dai , J. J. Xiang , M. D. Ding

Coronal holes (CH) are regions of open magnetic field lines in the solar corona and the source of fast solar wind. Understanding the evolution of coronal holes is critical for solar magnetism as well as for accurate space weather forecasts.…

Space Physics · Physics 2018-05-02 Amr Hamada , Timo Asikainen , Ilpo Virtanen , Kalevi Mursula

The coming decade will see the routine use of solar data of unprecedented spatial and spectral resolution, time cadence, and completeness. To capitalize on the new (or soon to be available) facilities such as SDO, ATST and FASR, and the…

Recent radioastronomical observations of Faraday rotation in the solar corona can be interpreted as evidence for coronal currents, with values as large as $2.5 \times 10^9$ Amperes (Spangler 2007). These estimates of currents are used to…

Astrophysics · Physics 2020-01-29 Steven R. Spangler

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Marina Battaglia , Eduard P. Kontar

To understand the nonlinear dynamics of the Parker scenario for coronal heating, long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry are carried out. A loop is modeled as a box extended along the…

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

The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec) and temporal (5.5s) resolution. The Hi-C observations show in some moss regions…

The problem of solar corona heating remains one of key puzzles in astrophysics for a few decades; but none of the proposed mechanisms can give a definitive answer to this question. As a result, the novel scenarios are still suggested. Here,…

Solar and Stellar Astrophysics · Physics 2020-05-15 Yurii V. Dumin

Context: Long-period intensity pulsations were recently detected in the EUV emission of coronal loops, and have been attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations…

Solar and Stellar Astrophysics · Physics 2020-02-12 Gabriel Pelouze , Frédéric Auchère , Karine Bocchialini , Clara Froment , Susanna Parenti , Elie Soubrié

Using Hinode EUV Imaging Spectrometer (EIS) spectra recorded daily at Sun center from the end of 2006 to early 2011, we studied the long-term evolution of the quiet corona. The light curves of the higher temperature emission lines exhibit…

Solar and Stellar Astrophysics · Physics 2012-07-17 S. Kamio , J. T. Mariska

The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower. The time delays between the different narrowband EUV channels have been measured for many…

Solar and Stellar Astrophysics · Physics 2017-03-22 Roberto Lionello , Caroline E. Alexander , Amy R. Winebarger , Jon A. Linker , Zoran Mikić
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