Evidence of Explosive Evaporation in a Microflare Observed by Hinode/EIS
Abstract
We present a detailed study of explosive chromospheric evaporation during a microflare which occurred on 2007 December 7 as observed with the Extreme-ultraviolet Imaging Spectrometer on board Hinode. We find temperature-dependent upflows for lines formed from 1.0 to 2.5 MK and downflows for lines formed from 0.05 to 0.63 MK in the impulsive phase of the flare. Both the line intensity and the nonthermal line width appear enhanced in most of the lines and are temporally correlated with the evaporation velocity. Our results are consistent with the numerical simulations of flare models, which take into account a strong nonthermal electron beam in producing the explosive chromospheric evaporation. The explosive evaporation observed in this microflare implies that the same dynamic processes may exist in events with very different magnitudes.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2010
- DOI:
- 10.1088/0004-637X/724/1/640
- arXiv:
- arXiv:1009.3193
- Bibcode:
- 2010ApJ...724..640C
- Keywords:
-
- line: profiles;
- Sun: flares;
- Sun: UV radiation;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 14 pages, 8 figures. Accepted for publication in the Astrophysical Journal