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Title: Observable Signatures of Energy Release in Braided Coronal Loops

Abstract

We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such field line tangling in the corona has long been postulated in the context of coronal heating models. We focus on the observational signatures of energy release in such braided magnetic structures using MHD simulations and forward modeling tools. The aim is to answer the following question: if energy release occurs in a coronal loop containing braided magnetic flux, should we expect a clearly observable signature in emissions? We demonstrate that the presence of braided magnetic field lines does not guarantee a braided appearance to the observed intensities. Observed intensities may—but need not necessarily—reveal the underlying braided nature of the magnetic field, depending on the degree and pattern of the field line tangling within the loop. However, in all cases considered, the evolution of the braided loop is accompanied by localized heating regions as the loop relaxes. Factors that may influence the observational signatures are discussed. Recent high-resolution observations from Hi-C have claimed the first direct evidence of braided magnetic fields in the corona. Here we show that both the Hi-C data and some of our simulations give the appearance of braiding at a range ofmore » scales.« less

Authors:
 [1];  [2]; ; ;  [3];  [4]
  1. University of Dundee, Nethergate, Dundee, DD1 4HN (United Kingdom)
  2. Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, F-91405, Orsay Cedex (France)
  3. NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)
  4. Niels Bohr Institute, Geological Museum Østervoldgade 5-7, DK-1350, Copenhagen K (Denmark)
Publication Date:
OSTI Identifier:
22661301
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 837; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; EMISSION; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETOHYDRODYNAMICS; RELAXATION; RESOLUTION; SIMULATION; SOLAR CORONA; SUN

Citation Formats

Pontin, D. I., Janvier, M., Tiwari, S. K., Winebarger, A. R., Cirtain, J. W., and Galsgaard, K. Observable Signatures of Energy Release in Braided Coronal Loops. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA5FF9.
Pontin, D. I., Janvier, M., Tiwari, S. K., Winebarger, A. R., Cirtain, J. W., & Galsgaard, K. Observable Signatures of Energy Release in Braided Coronal Loops. United States. doi:10.3847/1538-4357/AA5FF9.
Pontin, D. I., Janvier, M., Tiwari, S. K., Winebarger, A. R., Cirtain, J. W., and Galsgaard, K. Fri . "Observable Signatures of Energy Release in Braided Coronal Loops". United States. doi:10.3847/1538-4357/AA5FF9.
@article{osti_22661301,
title = {Observable Signatures of Energy Release in Braided Coronal Loops},
author = {Pontin, D. I. and Janvier, M. and Tiwari, S. K. and Winebarger, A. R. and Cirtain, J. W. and Galsgaard, K.},
abstractNote = {We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such field line tangling in the corona has long been postulated in the context of coronal heating models. We focus on the observational signatures of energy release in such braided magnetic structures using MHD simulations and forward modeling tools. The aim is to answer the following question: if energy release occurs in a coronal loop containing braided magnetic flux, should we expect a clearly observable signature in emissions? We demonstrate that the presence of braided magnetic field lines does not guarantee a braided appearance to the observed intensities. Observed intensities may—but need not necessarily—reveal the underlying braided nature of the magnetic field, depending on the degree and pattern of the field line tangling within the loop. However, in all cases considered, the evolution of the braided loop is accompanied by localized heating regions as the loop relaxes. Factors that may influence the observational signatures are discussed. Recent high-resolution observations from Hi-C have claimed the first direct evidence of braided magnetic fields in the corona. Here we show that both the Hi-C data and some of our simulations give the appearance of braiding at a range of scales.},
doi = {10.3847/1538-4357/AA5FF9},
journal = {Astrophysical Journal},
number = 2,
volume = 837,
place = {United States},
year = {Fri Mar 10 00:00:00 EST 2017},
month = {Fri Mar 10 00:00:00 EST 2017}
}