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Multi-wavelength observations and modelling of a canonical solar flare

Authors :
James A. Klimchuk
Ryan O. Milligan
C. L. Raftery
Peter T. Gallagher
Publication Year :
2008
Publisher :
arXiv, 2008.

Abstract

This paper investigates the temporal evolution of temperature, emission measure, energy loss and velocity in a C-class solar flare from both an observational and theoretical perspective. The properties of the flare were derived by following the systematic cooling of the plasma through the response functions of a number of instruments -- RHESSI (>5 MK), GOES-12 (5-30 MK), TRACE 171 A (1 MK) and SOHO/CDS (~0.03-8 MK). These measurements were studied in combination with simulations from the 0-D EBTEL model. At the flare on-set, upflows of ~90 km s-1 and low level emission were observed in Fe XIX, consistent with pre-flare heating and gentle chromospheric evaporation. During the impulsive phase, upflows of ~80 km s-1 in Fe XIX and simultaneous downflows of 20 km s-1 in He I and O V were observed, indicating explosive chromospheric evaporation. The plasma was subsequently found to reach a peak temperature of ~13 MK in approximately 10 minutes. Using EBTEL, conduction was found to be the dominant loss mechanism during the initial ~300s of the decay phase. It was also found to be responsible for driving gentle chromospheric evaporation during this period. As the temperature fell below ~8 MK, and for the next ~4,000s, radiative losses were determined to dominate over conductive losses. The radiative loss phase was accompanied by significant downflows of<br />10 pages, 7 figures, 2 tables. Accepted for publication in A&A

Details

Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....3ad4ea93b1545e7598962f4604e7cdcb
Full Text :
https://doi.org/10.48550/arxiv.0812.0311