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Title: First Imaging Observation of Standing Slow Wave in Coronal Fan Loops

Abstract

We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves that were generated due to X-class flares in the distant active region AR 11429. To characterize the nature of oscillations, we created time–distance maps along the fan loops and noted that the intensity oscillations at two ends of the loops were out of phase. As we move along the fan loop, the amplitude of the oscillations first decreased and then increased. The out-of-phase nature together with the amplitude variation along the loop implies that these oscillations are very likely to be standing waves. The period of the oscillations is estimated to be ∼27 minutes, damping time to be ∼45 minutes, and phase velocity projected in the plane of sky to be ∼65–83 km s{sup −1}. The projected phase speeds were in the range of the acoustic speed of coronal plasma at about 0.6 MK, which further indicates that these are slow waves. To the best of our knowledge, this is the first report on the existence of the standing slow waves in non-flaring fan loops.

Authors:
; ;  [1];  [2]
  1. Indian Institute of Astrophysics, Bangalore 560 034 (India)
  2. Institute of Space Science and Applied Technology, Harbin Institute of Technology, Shenzhen 518000 (China)
Publication Date:
OSTI Identifier:
22654388
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 847; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; DAMPING; EXPLOSIONS; FLARING; OSCILLATIONS; PHASE VELOCITY; PLASMA; STANDING WAVES; SUN; ULTRAVIOLET RADIATION

Citation Formats

Pant, V., Tiwari, A., Banerjee, D., and Yuan, D.. First Imaging Observation of Standing Slow Wave in Coronal Fan Loops. United States: N. p., 2017. Web. doi:10.3847/2041-8213/AA880F.
Pant, V., Tiwari, A., Banerjee, D., & Yuan, D.. First Imaging Observation of Standing Slow Wave in Coronal Fan Loops. United States. doi:10.3847/2041-8213/AA880F.
Pant, V., Tiwari, A., Banerjee, D., and Yuan, D.. Wed . "First Imaging Observation of Standing Slow Wave in Coronal Fan Loops". United States. doi:10.3847/2041-8213/AA880F.
@article{osti_22654388,
title = {First Imaging Observation of Standing Slow Wave in Coronal Fan Loops},
author = {Pant, V. and Tiwari, A. and Banerjee, D. and Yuan, D.},
abstractNote = {We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves that were generated due to X-class flares in the distant active region AR 11429. To characterize the nature of oscillations, we created time–distance maps along the fan loops and noted that the intensity oscillations at two ends of the loops were out of phase. As we move along the fan loop, the amplitude of the oscillations first decreased and then increased. The out-of-phase nature together with the amplitude variation along the loop implies that these oscillations are very likely to be standing waves. The period of the oscillations is estimated to be ∼27 minutes, damping time to be ∼45 minutes, and phase velocity projected in the plane of sky to be ∼65–83 km s{sup −1}. The projected phase speeds were in the range of the acoustic speed of coronal plasma at about 0.6 MK, which further indicates that these are slow waves. To the best of our knowledge, this is the first report on the existence of the standing slow waves in non-flaring fan loops.},
doi = {10.3847/2041-8213/AA880F},
journal = {Astrophysical Journal Letters},
number = 1,
volume = 847,
place = {United States},
year = {Wed Sep 20 00:00:00 EDT 2017},
month = {Wed Sep 20 00:00:00 EDT 2017}
}