Temperature and Emission-Measure Profiles along Long-lived Solar Coronal Loops Observed with the [ITAL]Transition Region and Coronal Explorer[/ITAL]

1999 ◽  
Vol 517 (2) ◽  
pp. L155-L158 ◽  
Author(s):  
Dawn D. Lenz ◽  
Edward E. DeLuca ◽  
Leon Golub ◽  
Robert Rosner ◽  
Jay A. Bookbinder
Keyword(s):  
Transition Region ◽  
Emission Measure ◽  
Coronal Loops ◽  
Solar Coronal

scholarly journals KAPPA: A Package for the Synthesis of Optically Thin Spectra for the Non-Maxwellian κ-distributions. II. Major Update to Compatibility with CHIANTI Version 10

2021 ◽  
Vol 257 (2) ◽  
pp. 62
Author(s):  
Elena Dzifčáková ◽  
Jaroslav Dudík ◽  
Alena Zemanová ◽  
Juraj Lörinčík ◽  
Marian Karlický
Keyword(s):  
Transition Region ◽  
Line Intensity ◽  
Coronal Loops ◽  
Relative Level ◽  
Intensity Ratios ◽  
Solar Coronal

Abstract KAPPA is a database and software for the calculation of the optically thin spectra for the non-Maxwellian κ-distributions that were recently diagnosed in the plasma of solar coronal loops, flares, as well as in the transition region. KAPPA is based on the widely used CHIANTI database and reproduces many of its capabilities for κ-distributions. Here we perform a major update of the KAPPA database, including a near-complete recalculation of the ionization, recombination, excitation, and deexcitation rates for all ions in the database, as well as an implementation of the two-ion model for calculations of relative-level populations (and intensities) if these are modified by ionization and recombination from or to excited levels. As an example of KAPPA usage, we explore novel diagnostics of κ, and show that O iii lines near 500 and 700 Å provide a strong sensitivity to κ, with some line intensity ratios changing by a factor of up to 2–4 compared to Maxwellian. This is much larger than previously employed diagnostics of κ.

scholarly journals Dynamics of solar coronal loops

2003 ◽  
Vol 411 (3) ◽  
pp. 605-613 ◽  
Author(s):  
D. A. N. Müller ◽  
V. H. Hansteen ◽  
H. Peter
Keyword(s):  
Coronal Loops ◽  
Solar Coronal

MULTI-STRANDED AND MULTI-THERMAL SOLAR CORONAL LOOPS: EVIDENCE FROMHINODEX-RAY TELESCOPE AND EUV IMAGING SPECTROMETER DATA

2010 ◽  
Vol 723 (2) ◽  
pp. 1180-1187 ◽  
Author(s):  
J. T. Schmelz ◽  
S. H. Saar ◽  
K. Nasraoui ◽  
V. L. Kashyap ◽  
M. A. Weber ◽  
...  
Keyword(s):  
Coronal Loops ◽  
Imaging Spectrometer ◽  
Spectrometer Data ◽  
Euv Imaging ◽  
Solar Coronal

Concerning the Dynamics of Energetic Protons in Coronal Magnetic Loops: Dispersion Effects of Alfven Waves

1985 ◽  
Vol 107 ◽  
pp. 559-559
Author(s):  
V. A. Mazur ◽  
A. V. Stepanov
Keyword(s):  
Magnetic Field ◽  
Wave Dispersion ◽  
Alfven Waves ◽  
Alfven Wave ◽  
Wave Number ◽  
Alfvén Waves ◽  
Coronal Loops ◽  
Coronal Magnetic Loops ◽  
The Magnetic Field ◽  
Solar Coronal

It is shown that the existence of plasma density inhomogeneities (ducts) elongated along the magnetic field in coronal loops, and of Alfven wave dispersion, associated with the taking into account of gyrotropy U ≡ ω/ωi ≪ 1 (Leonovich et al., 1983), leads to the possibility of a quasi-longitudinal k⊥ < √U k‖ propagation (wave guiding) of Alfven waves. Here ω is the frequency of Alfven waves, ωi is the proton gyrofrequency, and k is the wave number. It is found that with the parameter ξ = ω2 R/ωi A > 1, where R is the inhomogeneity scale of a loop across the magnetic field, and A is the Alfven wave velocity, refraction of Alfven waves does not lead, as contrasted to Wentzel's inference (1976), to the waves going out of the regime of quasi-longitudinal propagation. As the result, the amplification of Alfven waves in solar coronal loops can be important. A study is made of the cyclotron instability of Alfven waves under solar coronal conditions.

Repeated Coronal Condensations Caused by Magnetic Reconnection between Solar Coronal Loops

2019 ◽  
Vol 884 (1) ◽  
pp. 34 ◽  
Author(s):  
Leping Li ◽  
Hardi Peter ◽  
Lakshmi Pradeep Chitta ◽  
Jun Zhang ◽  
Jiangtao Su ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Coronal Loops ◽  
Solar Coronal

scholarly journals Self-organized braiding in solar coronal loops

2015 ◽  
Vol 81 (4) ◽  
Author(s):  
M. A. Berger ◽  
M. Asgari-Targhi ◽  
E. E. DeLuca
Keyword(s):  
Coronal Loops ◽  
Frequency Distributions ◽  
Fire Model ◽  
X Ray ◽  
Self Organized ◽  
Forest Fire Model ◽  
Distribution Laws ◽  
Field Lines ◽  
Power Law Distributions ◽  
Solar Coronal

AbstractIn this paper, we investigate the evolution of braided solar coronal loops. We assume that coronal loops consist of several internal strands which twist and braid about each other. Reconnection between the strands leads to small flares and heating of the loop to x-ray temperatures. Using a method of generating and releasing braid structure similar to a forest fire model, we show that the reconnected field lines evolve to a self-organised critical state. In this state, the frequency distributions of coherent braid sequences as well as flare energies follow power law distributions. We demonstrate how the presence of net helicity in the loop alters the distribution laws.

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