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Title: A Large-scale Plume in an X-class Solar Flare

Abstract

Ever-increasing multi-frequency imaging of solar observations suggests that solar flares often involve more than one magnetic fluxtube. Some of the fluxtubes are closed, while others can contain open fields. The relative proportion of nonthermal electrons among those distinct loops is highly important for understanding energy release, particle acceleration, and transport. The access of nonthermal electrons to the open field is also important because the open field facilitates the solar energetic particle (SEP) escape from the flaring site, and thus controls the SEP fluxes in the solar system, both directly and as seed particles for further acceleration. The large-scale fluxtubes are often filled with a tenuous plasma, which is difficult to detect in either EUV or X-ray wavelengths; however, they can dominate at low radio frequencies, where a modest component of nonthermal electrons can render the source optically thick and, thus, bright enough to be observed. Here we report the detection of a large-scale “plume” at the impulsive phase of an X-class solar flare, SOL2001-08-25T16:23, using multi-frequency radio data from Owens Valley Solar Array. To quantify the flare’s spatial structure, we employ 3D modeling utilizing force-free-field extrapolations from the line of sight SOHO /MDI magnetograms with our modeling tool GX-Simulator. Wemore » found that a significant fraction of the nonthermal electrons that accelerated at the flare site low in the corona escapes to the plume, which contains both closed and open fields. We propose that the proportion between the closed and open fields at the plume is what determines the SEP population escaping into interplanetary space.« less

Authors:
; ;  [1]
  1. Physics Department, Center for Solar-Terrestrial Research, New Jersey Institute of Technology Newark, NJ, 07102-1982 (United States)
Publication Date:
OSTI Identifier:
22663224
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 845; Journal Issue: 2; 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; ACCELERATION; COSMIC X-RAY SOURCES; DETECTION; ELECTRONS; EMISSION; EXTRAPOLATION; INTERPLANETARY SPACE; MAGNETIC FIELDS; PLUMES; RADIOWAVE RADIATION; SIMULATION; SOLAR FLARES; SOLAR SYSTEM; SUN; WAVELENGTHS

Citation Formats

Fleishman, Gregory D., Nita, Gelu M., and Gary, Dale E. A Large-scale Plume in an X-class Solar Flare. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA81D4.
Fleishman, Gregory D., Nita, Gelu M., & Gary, Dale E. A Large-scale Plume in an X-class Solar Flare. United States. doi:10.3847/1538-4357/AA81D4.
Fleishman, Gregory D., Nita, Gelu M., and Gary, Dale E. Sun . "A Large-scale Plume in an X-class Solar Flare". United States. doi:10.3847/1538-4357/AA81D4.
@article{osti_22663224,
title = {A Large-scale Plume in an X-class Solar Flare},
author = {Fleishman, Gregory D. and Nita, Gelu M. and Gary, Dale E.},
abstractNote = {Ever-increasing multi-frequency imaging of solar observations suggests that solar flares often involve more than one magnetic fluxtube. Some of the fluxtubes are closed, while others can contain open fields. The relative proportion of nonthermal electrons among those distinct loops is highly important for understanding energy release, particle acceleration, and transport. The access of nonthermal electrons to the open field is also important because the open field facilitates the solar energetic particle (SEP) escape from the flaring site, and thus controls the SEP fluxes in the solar system, both directly and as seed particles for further acceleration. The large-scale fluxtubes are often filled with a tenuous plasma, which is difficult to detect in either EUV or X-ray wavelengths; however, they can dominate at low radio frequencies, where a modest component of nonthermal electrons can render the source optically thick and, thus, bright enough to be observed. Here we report the detection of a large-scale “plume” at the impulsive phase of an X-class solar flare, SOL2001-08-25T16:23, using multi-frequency radio data from Owens Valley Solar Array. To quantify the flare’s spatial structure, we employ 3D modeling utilizing force-free-field extrapolations from the line of sight SOHO /MDI magnetograms with our modeling tool GX-Simulator. We found that a significant fraction of the nonthermal electrons that accelerated at the flare site low in the corona escapes to the plume, which contains both closed and open fields. We propose that the proportion between the closed and open fields at the plume is what determines the SEP population escaping into interplanetary space.},
doi = {10.3847/1538-4357/AA81D4},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 845,
place = {United States},
year = {2017},
month = {8}
}