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EUV and HXR evidence of chromospheric evaporation in a solar flare. NING Zongjun Purple Mountain Observatory. 2007 Dec. 14 C1.1 flare joint observed by RHESSI, Hinode/EIS and TRACE. RHESSI 12-25 keV.
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EUV and HXR evidence of chromospheric evaporation in a solar flare NING Zongjun Purple Mountain Observatory
2007 Dec. 14 C1.1 flare joint observed by RHESSI, Hinode/EIS and TRACE. RHESSI 12-25 keV Milligan & Dennis (2009) focused on the EUV line characteristics after the explosive chromospheric evaporation in the 2007 Dec. 14 flare. Milligan & Dennis 2009 Hinode/EIS raster
What did we do then? 1. We studied the EUV Doppler velocity image on the flare kernels. 2. We analyzed the RHESSI images at different times and different bands to display the evaporation evidence at X-rays. What could we expect from the X-ray images when the evaporation takes place? EIS raster interval ……… source distribution Interval of RHESSI images
Time-dependence distribution & energy-dependence distribution 1. time-dependence: The earlier X-rays originate from the deeper layers or further wary from the loop top. evaporation 2. energy-dependence: The higher energy X-rays originate from the deeper layers or further wary from the loop top. evaporation
Observations time-dependence energy-depe at 6-9 keV ndence at 14:14:35 UT Major premise: In order to explain the energy-dependence and time-dependent source distributions, the 6-9 keV emission has to be nonthermal bremsstrahlung, at least, nonthermal dominant. We have to prove it from observations.
6-9 keV emission Three possibilities: 1. thermal emission 2. nonthermal emission 3. mixture of both We have to prove How to prove the nonthermal dominant? 1. column density 2. similarity between light curves at 6-9 keV and 15-25 keV.
Nonthermal dominant at 6-9 keV 1.Column density: Required density: ne is comparable to the required nstop indicating that nonthermal electrons with 6-9 keV could be stopped by the loop plasma. Others: (Milligan & Dennis 2009)
Nonthermal dominant at 6-9 keV 2.The similarity between the light curves at 6-9 keV and 15-25 keV. 6-9 keV 15-25 keV GOES derivative
Evaporation velocity (~408 km/s) 317 km/s 257 km/s
Summary 2007 Dec. 14 flare, C1.1 We found the time-dependence and energy-dependence source distributions of X-rays overlapped on the EUV bright kernels with blue shifted. (Ning 2010, submitted)
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