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Title: FLARE ENERGY BUILD-UP IN A DECAYING ACTIVE REGION NEAR A CORONAL HOLE

Abstract

A B1.7 two-ribbon flare occurred in a highly non-potential decaying active region near a coronal hole at 10:00 UT on 2008 May 17. This flare is 'large' in the sense that it involves the entire region, and it is associated with both a filament eruption and a coronal mass ejection. We present multi-wavelength observations from EUV (TRACE, STEREO/EUVI), X-rays (Hinode/XRT), and Halpha (THEMIS, BBSO) prior to, during and after the flare. Prior to the flare, the region contained two filaments. The long J-shaped sheared loops corresponding to the southern filament were evolved from two short loop systems, which happened around 22:00 UT after a filament eruption on May 16. Formation of highly sheared loops in the southeastern part of the region was observed by STEREO 8 hr before the flare. We also perform nonlinear force-free field (NLFFF) modeling for the region at two times prior to the flare, using the flux rope insertion method. The models include the non-force-free effect of magnetic buoyancy in the photosphere. The best-fit NLFFF models show good fit to observations both in the corona (X-ray and EUV loops) and chromosphere (Halpha filament). We find that the horizontal fields in the photosphere are relatively insensitive tomore » the present of flux ropes in the corona. The axial flux of the flux rope in the NLFFF model on May 17 is twice that on May 16, and the model on May 17 is only marginally stable. We also find that the quasi-circular flare ribbons are associated with the separatrix between open and closed fields. This observation and NLFFF modeling suggest that this flare may be triggered by the reconnection at the null point on the separatrix surface.« less

Authors:
; ;  [1]; ; ;  [2]
  1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
  2. Observatoire de Paris, Section de Meudon, LESIA, 92195 Meudon Principal Cedex (France)
Publication Date:
OSTI Identifier:
21367453
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 704; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/704/1/341; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHROMOSPHERE; ERUPTION; FILAMENTS; GAMMA RADIATION; MAGNETIC FIELDS; MASS; NONLINEAR PROBLEMS; PHOTOSPHERE; POTENTIALS; SIMULATION; SUN; SURFACES; WAVELENGTHS; X RADIATION; ATMOSPHERES; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; MAIN SEQUENCE STARS; RADIATIONS; SOLAR ATMOSPHERE; STARS; STELLAR ATMOSPHERES

Citation Formats

Yingna, Su, Van Ballegooijen, Adriaan, Golub, Leon, Schmieder, Brigitte, Berlicki, Arkadiusz, Guo, Yang, and Huang Guangli, E-mail: ynsu@head.cfa.harvard.ed. FLARE ENERGY BUILD-UP IN A DECAYING ACTIVE REGION NEAR A CORONAL HOLE. United States: N. p., 2009. Web. doi:10.1088/0004-637X/704/1/341.
Yingna, Su, Van Ballegooijen, Adriaan, Golub, Leon, Schmieder, Brigitte, Berlicki, Arkadiusz, Guo, Yang, & Huang Guangli, E-mail: ynsu@head.cfa.harvard.ed. FLARE ENERGY BUILD-UP IN A DECAYING ACTIVE REGION NEAR A CORONAL HOLE. United States. https://doi.org/10.1088/0004-637X/704/1/341
Yingna, Su, Van Ballegooijen, Adriaan, Golub, Leon, Schmieder, Brigitte, Berlicki, Arkadiusz, Guo, Yang, and Huang Guangli, E-mail: ynsu@head.cfa.harvard.ed. 2009. "FLARE ENERGY BUILD-UP IN A DECAYING ACTIVE REGION NEAR A CORONAL HOLE". United States. https://doi.org/10.1088/0004-637X/704/1/341.
@article{osti_21367453,
title = {FLARE ENERGY BUILD-UP IN A DECAYING ACTIVE REGION NEAR A CORONAL HOLE},
author = {Yingna, Su and Van Ballegooijen, Adriaan and Golub, Leon and Schmieder, Brigitte and Berlicki, Arkadiusz and Guo, Yang and Huang Guangli, E-mail: ynsu@head.cfa.harvard.ed},
abstractNote = {A B1.7 two-ribbon flare occurred in a highly non-potential decaying active region near a coronal hole at 10:00 UT on 2008 May 17. This flare is 'large' in the sense that it involves the entire region, and it is associated with both a filament eruption and a coronal mass ejection. We present multi-wavelength observations from EUV (TRACE, STEREO/EUVI), X-rays (Hinode/XRT), and Halpha (THEMIS, BBSO) prior to, during and after the flare. Prior to the flare, the region contained two filaments. The long J-shaped sheared loops corresponding to the southern filament were evolved from two short loop systems, which happened around 22:00 UT after a filament eruption on May 16. Formation of highly sheared loops in the southeastern part of the region was observed by STEREO 8 hr before the flare. We also perform nonlinear force-free field (NLFFF) modeling for the region at two times prior to the flare, using the flux rope insertion method. The models include the non-force-free effect of magnetic buoyancy in the photosphere. The best-fit NLFFF models show good fit to observations both in the corona (X-ray and EUV loops) and chromosphere (Halpha filament). We find that the horizontal fields in the photosphere are relatively insensitive to the present of flux ropes in the corona. The axial flux of the flux rope in the NLFFF model on May 17 is twice that on May 16, and the model on May 17 is only marginally stable. We also find that the quasi-circular flare ribbons are associated with the separatrix between open and closed fields. This observation and NLFFF modeling suggest that this flare may be triggered by the reconnection at the null point on the separatrix surface.},
doi = {10.1088/0004-637X/704/1/341},
url = {https://www.osti.gov/biblio/21367453}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 704,
place = {United States},
year = {Sat Oct 10 00:00:00 EDT 2009},
month = {Sat Oct 10 00:00:00 EDT 2009}
}