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Title: MAJOR ELECTRON EVENTS AND CORONAL MAGNETIC CONFIGURATIONS OF THE RELATED SOLAR ACTIVE REGIONS

Abstract

A statistical survey of 26 major electron events during the period 2002 February through the end of solar cycle 23 is presented. We have obtained electron solar onset times and the peak flux spectra for each event by fitting to a power-law spectrum truncated by an exponential high-energy tail, i.e., f(E){approx}E{sup -{delta}}e{sup -E/E{sub 0}}. We also derived the coronal magnetic configurations of the related solar active regions (ARs) from the potential-field source-surface model. It is found that (1) 10 of the 11 well-connected open field-line events are prompt events whose solar onset times coincide with the maxima of flare emission and 13 of the 14 closed field-line events are delayed events. (2) A not-well-connected open field-line event and one of the closed field-line events are prompt events, they are both associated with large-scale coronal disturbances or dimming. (3) An averaged harder spectrum is found in open field-line events compared with the closed ones. Specifically, the averaged spectral index {delta} is of 1.6 {+-} 0.3 in open field-line events and of 2.0 {+-} 0.4 in closed ones. The spectra of three closed field-line events show infinite rollover energies E {sub 0}. These correlations clearly establish a significant link between the coronalmore » magnetic field-line topology and the escape of charged particles from the flaring ARs into interplanetary space during the major solar energetic particle events.« less

Authors:
; ;  [1]; ;  [2]
  1. Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT (United Kingdom)
  2. Department of Astronomy, Nanjing University, Nanjing 210093 (China)
Publication Date:
OSTI Identifier:
21452847
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 720; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/720/1/L36; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHARGED PARTICLES; INTERPLANETARY SPACE; MAGNETIC FIELDS; SOLAR CYCLE; SOLAR FLARES; SOLAR RADIATION; SUN; MAIN SEQUENCE STARS; RADIATIONS; SOLAR ACTIVITY; SPACE; STARS; STELLAR ACTIVITY; STELLAR FLARES; STELLAR RADIATION

Citation Formats

Li, C., Owen, C. J., Matthews, S. A., Dai, Y., and Tang, Y. H., E-mail: cl2@mssl.ucl.ac.u. MAJOR ELECTRON EVENTS AND CORONAL MAGNETIC CONFIGURATIONS OF THE RELATED SOLAR ACTIVE REGIONS. United States: N. p., 2010. Web. doi:10.1088/2041-8205/720/1/L36.
Li, C., Owen, C. J., Matthews, S. A., Dai, Y., & Tang, Y. H., E-mail: cl2@mssl.ucl.ac.u. MAJOR ELECTRON EVENTS AND CORONAL MAGNETIC CONFIGURATIONS OF THE RELATED SOLAR ACTIVE REGIONS. United States. doi:10.1088/2041-8205/720/1/L36.
Li, C., Owen, C. J., Matthews, S. A., Dai, Y., and Tang, Y. H., E-mail: cl2@mssl.ucl.ac.u. Wed . "MAJOR ELECTRON EVENTS AND CORONAL MAGNETIC CONFIGURATIONS OF THE RELATED SOLAR ACTIVE REGIONS". United States. doi:10.1088/2041-8205/720/1/L36.
@article{osti_21452847,
title = {MAJOR ELECTRON EVENTS AND CORONAL MAGNETIC CONFIGURATIONS OF THE RELATED SOLAR ACTIVE REGIONS},
author = {Li, C. and Owen, C. J. and Matthews, S. A. and Dai, Y. and Tang, Y. H., E-mail: cl2@mssl.ucl.ac.u},
abstractNote = {A statistical survey of 26 major electron events during the period 2002 February through the end of solar cycle 23 is presented. We have obtained electron solar onset times and the peak flux spectra for each event by fitting to a power-law spectrum truncated by an exponential high-energy tail, i.e., f(E){approx}E{sup -{delta}}e{sup -E/E{sub 0}}. We also derived the coronal magnetic configurations of the related solar active regions (ARs) from the potential-field source-surface model. It is found that (1) 10 of the 11 well-connected open field-line events are prompt events whose solar onset times coincide with the maxima of flare emission and 13 of the 14 closed field-line events are delayed events. (2) A not-well-connected open field-line event and one of the closed field-line events are prompt events, they are both associated with large-scale coronal disturbances or dimming. (3) An averaged harder spectrum is found in open field-line events compared with the closed ones. Specifically, the averaged spectral index {delta} is of 1.6 {+-} 0.3 in open field-line events and of 2.0 {+-} 0.4 in closed ones. The spectra of three closed field-line events show infinite rollover energies E {sub 0}. These correlations clearly establish a significant link between the coronal magnetic field-line topology and the escape of charged particles from the flaring ARs into interplanetary space during the major solar energetic particle events.},
doi = {10.1088/2041-8205/720/1/L36},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 720,
place = {United States},
year = {2010},
month = {9}
}