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Title: Magnetic structure and nonthermal electrons in the X6.9 flare on 2011 August 9

The 2011 August 9 flare is one of the largest X-ray flares of sunspot cycle 24, but spatial information is rather limited due to its position close to the western limb. This paper presents information about the location of high-energy electrons derived from hard X-ray and microwave spectra obtained with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) and the Korean Solar Radio Burst Locator (KSRBL), respectively. The KSRBL microwave spectrum shows significant fluxes at low frequencies, implying that the high-energy electrons reside in a coronal volume highly concentrated at strong magnetic fields, and rapidly expanding with decreasing magnetic fields. After a simple modeling of the microwave spectrum, we found that the microwave source should be located above the inner pair of magnetic poles in a large quadrupolar configuration. The time-dependent evolution of the magnetic field distribution and total nonthermal energy derived from the microwave spectra is also consistent with the standard picture of multiple magnetic reconnections recurring at a magnetic null point that forms above the magnetic quadrupoles and moves up with time.
Authors:
;  [1] ;  [2] ; ; ; ; ; ;  [3]
  1. Department of Astronomy and Space Science, Chungbuk National University, Cheongju (Korea, Republic of)
  2. Physics Department, New Jersey Institute of Technology, Newark, NJ 07102 (United States)
  3. Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22370171
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 796; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DISTRIBUTION; GAMMA RADIATION; HARD X RADIATION; MAGNETIC FIELDS; MAGNETIC RECONNECTION; MICROWAVE RADIATION; MICROWAVE SPECTRA; QUADRUPOLAR CONFIGURATIONS; QUADRUPOLES; SIMULATION; SOLAR RADIO BURSTS; STAR EVOLUTION; SUN; SUNSPOTS; TIME DEPENDENCE