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Title: STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD

Abstract

We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s{sup −1} in the tornado-like structure. Between the twomore » legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.« less

Authors:
;  [1];  [2];  [3]
  1. SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)
  2. Observatoire de Paris, Meudon, F-92195 (France)
  3. Institut de Recherche en Astrophysique et Planétologie, Toulouse (France)
Publication Date:
OSTI Identifier:
22521586
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 818; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALCIUM IONS; DOPPLER EFFECT; FILAMENTS; IMAGES; MAGNESIUM IONS; MAGNETIC FIELDS; PLASMA; POLARIMETRY; SOLAR PROMINENCES; SPATIAL RESOLUTION; SUN; TELESCOPES; ULTRAVIOLET RADIATION

Citation Formats

Levens, P. J., Labrosse, N., Schmieder, B., and Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk. STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD. United States: N. p., 2016. Web. doi:10.3847/0004-637X/818/1/31.
Levens, P. J., Labrosse, N., Schmieder, B., & Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk. STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD. United States. doi:10.3847/0004-637X/818/1/31.
Levens, P. J., Labrosse, N., Schmieder, B., and Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk. Wed . "STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD". United States. doi:10.3847/0004-637X/818/1/31.
@article{osti_22521586,
title = {STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD},
author = {Levens, P. J. and Labrosse, N. and Schmieder, B. and Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk},
abstractNote = {We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s{sup −1} in the tornado-like structure. Between the two legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.},
doi = {10.3847/0004-637X/818/1/31},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 818,
place = {United States},
year = {2016},
month = {2}
}