THE SOLAR DECIMETRIC SPIKE BURST OF 2006 DECEMBER 6: POSSIBLE EVIDENCE FOR FIELD-ALIGNED POTENTIAL DROPS IN POST-ERUPTION LOOPS
- Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, MA (United States)
A 1.4 GHz solar radio burst associated with a 3B/X6 eruptive flare on 2006 December 6 had the highest peak flux density ({approx}10{sup 6} sfu) of any event yet recorded at this frequency. The decimetric event characteristics during the brightest emission phase (numerous intense, short-lived, narrow-band bursts that overlapped to form a continuous spectrum) suggest electron cyclotron maser (ECM) emission. The peak 1.4 GHz emission did not occur during the flare impulsive phase but rather {approx}45 minutes later, in association with post-eruption loop activity seen in H{alpha} and by the Hinode EUV Imaging Spectrometer. During the Waves/LASCO era, three other delayed bursts with peak intensities >10{sup 5} sfu in the 1.0-1.6 GHz (L-band) frequency range have been reported that appear to have characteristics similar to the December 6 burst. In each of these three cases, high-frequency type IV bursts were reported in a range from {approx}150 to {approx}1500 MHz. Assuming a common ECM emission mechanism across this frequency range implies a broad span of source heights in the associated post-eruption loop systems. Difficulties with an ECM interpretation for these events include the generation of the lower frequency component of the type IVs and the long-standing problem of escape of the ECM emission from the loops. Magnetic-field-aligned potential drops, analogous to those observed for Earth's auroral kilometric radiation, could plausibly remove both of these objections to ECM emission.
- OSTI ID:
- 22004436
- Journal Information:
- Astrophysical Journal, Vol. 743, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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