Coronal nonthermal velocity following helicity injection before an X-class flare

L. K. Harra; D. R. Williams; A. J. Wallace; T. Magara; H. Hara; S. Tsuneta; A. C. Sterling; G. A. Doschek

doi:10.1088/0004-637X/691/2/L99

Coronal nonthermal velocity following helicity injection before an X-class flare

L. K. Harra, D. R. Williams, A. J. Wallace, T. Magara, H. Hara, S. Tsuneta, A. C. Sterling, G. A. Doschek

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37 Citations (Scopus)

Abstract

We explore the "pre-flare" behavior of the corona in a three-day period building up to an X-class flare on 2006 December 13 by analyzing EUV spectral profiles from the Hinode EUV Imaging Spectrometer (EIS) instrument. We found an increase in the coronal spectral line widths, beginning after the time of saturation of the injected helicity as measured by Magara & Tsuneta. In addition, this increase in line widths (indicating nonthermal motions) starts before any eruptive activity occurs. The Hinode EIS has the sensitivity to measure changes in the buildup to a flare many hours before the flare begins.

Original language	English
Pages (from-to)	L99-L102
Journal	Astrophysical Journal
Volume	691
Issue number	2 PART 2
DOIs	https://doi.org/10.1088/0004-637X/691/2/L99
Publication status	Published - 2009

Keywords

Corona
Flares
Sun

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10.1088/0004-637X/691/2/L99

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abstract = "We explore the {"}pre-flare{"} behavior of the corona in a three-day period building up to an X-class flare on 2006 December 13 by analyzing EUV spectral profiles from the Hinode EUV Imaging Spectrometer (EIS) instrument. We found an increase in the coronal spectral line widths, beginning after the time of saturation of the injected helicity as measured by Magara & Tsuneta. In addition, this increase in line widths (indicating nonthermal motions) starts before any eruptive activity occurs. The Hinode EIS has the sensitivity to measure changes in the buildup to a flare many hours before the flare begins.",

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T1 - Coronal nonthermal velocity following helicity injection before an X-class flare

AU - Harra, L. K.

AU - Williams, D. R.

AU - Wallace, A. J.

AU - Magara, T.

AU - Hara, H.

AU - Tsuneta, S.

AU - Sterling, A. C.

AU - Doschek, G. A.

PY - 2009

Y1 - 2009

N2 - We explore the "pre-flare" behavior of the corona in a three-day period building up to an X-class flare on 2006 December 13 by analyzing EUV spectral profiles from the Hinode EUV Imaging Spectrometer (EIS) instrument. We found an increase in the coronal spectral line widths, beginning after the time of saturation of the injected helicity as measured by Magara & Tsuneta. In addition, this increase in line widths (indicating nonthermal motions) starts before any eruptive activity occurs. The Hinode EIS has the sensitivity to measure changes in the buildup to a flare many hours before the flare begins.

AB - We explore the "pre-flare" behavior of the corona in a three-day period building up to an X-class flare on 2006 December 13 by analyzing EUV spectral profiles from the Hinode EUV Imaging Spectrometer (EIS) instrument. We found an increase in the coronal spectral line widths, beginning after the time of saturation of the injected helicity as measured by Magara & Tsuneta. In addition, this increase in line widths (indicating nonthermal motions) starts before any eruptive activity occurs. The Hinode EIS has the sensitivity to measure changes in the buildup to a flare many hours before the flare begins.

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KW - Sun

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VL - 691

SP - L99-L102

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 PART 2

ER -

Coronal nonthermal velocity following helicity injection before an X-class flare

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Keywords

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