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Title: High-resolution x-ray spectra of solar flares. VII. A long-duration x-ray flare associated with a coronal mass ejection

Abstract

X-ray spectra from the P78-1 spacecraft are discussed for a long-duration X-ray flare (>M8) that occurred for at least 6 hr behind and above the west solar limb on 1980 November 14. The X-ray flare was associated with a large coronal mass ejection that was observed with the white-light coronagraph on P78-1. The X-ray emission regions were at least 1'--2' above the solar surface, and extended over an angular distance of as much as 3'. These parameters are not typical for soft X-ray compact flares, which are much smaller and occur in closed-loop structures lower in the solar atmosphere. Emission measures for this flare vary between 10/sup 48/ and 10/sup 49/ cm/sup -3/ and are probably larger, since part of the emission may have been occulted by the solar limb. The combination of emission measure and source size implies the existence of small, high-density structures within a considerably larger volume. The November 14 X-ray line profiles exhibit large widths and complicated structure on the red and blue wings. The source size appears to decrease as the flare progresses, and the event increases in height above the limb. The rising motion is at a rate of less than 30 km s/supmore » -1/ near 0700 UT and decreases very shortly thereafter to low speeds of about 1.7 km s/sup -1/ at approx.1300 UT. Data are not available after 1400 UT. The November 14 flare appears to be a very bright example of a class of spatially large, long-duration X-ray events originally recognized from the analysis of data obtained from Skylab.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
E. O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC
OSTI Identifier:
5516040
Resource Type:
Journal Article
Journal Name:
Astrophys. J.; (United States)
Additional Journal Information:
Journal Volume: 292:1
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; SOLAR FLARES; X-RAY SPECTRA; EMISSION; IMAGES; LINE WIDTHS; SOLAR CORONA; SOLAR X-RAY BURSTS; ATMOSPHERES; SOLAR ACTIVITY; SPECTRA; STELLAR ATMOSPHERES; STELLAR CORONAE; 640104* - Astrophysics & Cosmology- Solar Phenomena

Citation Formats

Kreplin, R W, Doschek, G A, Feldman, U, Sheeley, Jr, N R, and Seely, J F. High-resolution x-ray spectra of solar flares. VII. A long-duration x-ray flare associated with a coronal mass ejection. United States: N. p., 1985. Web. doi:10.1086/163161.
Kreplin, R W, Doschek, G A, Feldman, U, Sheeley, Jr, N R, & Seely, J F. High-resolution x-ray spectra of solar flares. VII. A long-duration x-ray flare associated with a coronal mass ejection. United States. https://doi.org/10.1086/163161
Kreplin, R W, Doschek, G A, Feldman, U, Sheeley, Jr, N R, and Seely, J F. 1985. "High-resolution x-ray spectra of solar flares. VII. A long-duration x-ray flare associated with a coronal mass ejection". United States. https://doi.org/10.1086/163161.
@article{osti_5516040,
title = {High-resolution x-ray spectra of solar flares. VII. A long-duration x-ray flare associated with a coronal mass ejection},
author = {Kreplin, R W and Doschek, G A and Feldman, U and Sheeley, Jr, N R and Seely, J F},
abstractNote = {X-ray spectra from the P78-1 spacecraft are discussed for a long-duration X-ray flare (>M8) that occurred for at least 6 hr behind and above the west solar limb on 1980 November 14. The X-ray flare was associated with a large coronal mass ejection that was observed with the white-light coronagraph on P78-1. The X-ray emission regions were at least 1'--2' above the solar surface, and extended over an angular distance of as much as 3'. These parameters are not typical for soft X-ray compact flares, which are much smaller and occur in closed-loop structures lower in the solar atmosphere. Emission measures for this flare vary between 10/sup 48/ and 10/sup 49/ cm/sup -3/ and are probably larger, since part of the emission may have been occulted by the solar limb. The combination of emission measure and source size implies the existence of small, high-density structures within a considerably larger volume. The November 14 X-ray line profiles exhibit large widths and complicated structure on the red and blue wings. The source size appears to decrease as the flare progresses, and the event increases in height above the limb. The rising motion is at a rate of less than 30 km s/sup -1/ near 0700 UT and decreases very shortly thereafter to low speeds of about 1.7 km s/sup -1/ at approx.1300 UT. Data are not available after 1400 UT. The November 14 flare appears to be a very bright example of a class of spatially large, long-duration X-ray events originally recognized from the analysis of data obtained from Skylab.},
doi = {10.1086/163161},
url = {https://www.osti.gov/biblio/5516040}, journal = {Astrophys. J.; (United States)},
number = ,
volume = 292:1,
place = {United States},
year = {Wed May 01 00:00:00 EDT 1985},
month = {Wed May 01 00:00:00 EDT 1985}
}