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Title: Comparison of emission properties of two homologous flares in AR 11283

Abstract

Large, complex, active regions may produce multiple flares within a certain period of one or two days. These flares could occur in the same location with similar morphologies, commonly referred to as 'homologous flares'. In 2011 September, active region NOAA 11283 produced a pair of homologous flares on the 6th and 7th, respectively. Both of them were white-light (WL) flares, as captured by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory in visible continuum at 6173 Å which is believed to originate from the deep solar atmosphere. We investigate the WL emission of these X-class flares with HMI's seeing-free imaging spectroscopy. The durations of impulsive peaks in the continuum are about 4 minutes. We compare the WL with hard X-ray (HXR) observations for the September 6 flare and find a good correlation between the continuum and HXR both spatially and temporally. In absence of RHESSI data during the second flare on September 7, the derivative of the GOES soft X-ray is used and also found to be well correlated temporally with the continuum. We measure the contrast enhancements, characteristic sizes, and HXR fluxes of the twin flares, which are similar for both flares, indicating analogous triggeringmore » and heating processes. However, the September 7 flare was associated with conspicuous sunquake signals whereas no seismic wave was detected during the flare on September 6. Therefore, this comparison suggests that the particle bombardment may not play a dominant role in producing the sunquake events studied in this paper.« less

Authors:
; ; ;  [1]
  1. Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology 323 Martin Luther King Boulevard, Newark, NJ 07102-1982 (United States)
Publication Date:
OSTI Identifier:
22356894
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 787; 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; COMPARATIVE EVALUATIONS; CORRELATIONS; EMISSION; HARD X RADIATION; PARTICLES; PHOTOSPHERE; SEISMIC WAVES; SOFT X RADIATION; SPECTROSCOPY; SUN; VISIBLE RADIATION

Citation Formats

Xu, Yan, Jing, Ju, Wang, Shuo, and Wang, Haimin. Comparison of emission properties of two homologous flares in AR 11283. United States: N. p., 2014. Web. doi:10.1088/0004-637X/787/1/7.
Xu, Yan, Jing, Ju, Wang, Shuo, & Wang, Haimin. Comparison of emission properties of two homologous flares in AR 11283. United States. https://doi.org/10.1088/0004-637X/787/1/7
Xu, Yan, Jing, Ju, Wang, Shuo, and Wang, Haimin. 2014. "Comparison of emission properties of two homologous flares in AR 11283". United States. https://doi.org/10.1088/0004-637X/787/1/7.
@article{osti_22356894,
title = {Comparison of emission properties of two homologous flares in AR 11283},
author = {Xu, Yan and Jing, Ju and Wang, Shuo and Wang, Haimin},
abstractNote = {Large, complex, active regions may produce multiple flares within a certain period of one or two days. These flares could occur in the same location with similar morphologies, commonly referred to as 'homologous flares'. In 2011 September, active region NOAA 11283 produced a pair of homologous flares on the 6th and 7th, respectively. Both of them were white-light (WL) flares, as captured by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory in visible continuum at 6173 Å which is believed to originate from the deep solar atmosphere. We investigate the WL emission of these X-class flares with HMI's seeing-free imaging spectroscopy. The durations of impulsive peaks in the continuum are about 4 minutes. We compare the WL with hard X-ray (HXR) observations for the September 6 flare and find a good correlation between the continuum and HXR both spatially and temporally. In absence of RHESSI data during the second flare on September 7, the derivative of the GOES soft X-ray is used and also found to be well correlated temporally with the continuum. We measure the contrast enhancements, characteristic sizes, and HXR fluxes of the twin flares, which are similar for both flares, indicating analogous triggering and heating processes. However, the September 7 flare was associated with conspicuous sunquake signals whereas no seismic wave was detected during the flare on September 6. Therefore, this comparison suggests that the particle bombardment may not play a dominant role in producing the sunquake events studied in this paper.},
doi = {10.1088/0004-637X/787/1/7},
url = {https://www.osti.gov/biblio/22356894}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 787,
place = {United States},
year = {Tue May 20 00:00:00 EDT 2014},
month = {Tue May 20 00:00:00 EDT 2014}
}