Title: Multi-wavelength spectroscopic observation of EUV jet in AR 10960 Authors: Y. Matsui, T. Yokoyama, N. Kitagawa, S. Imada
We have studied the relationship between the velocity and temperature of a solar EUV jet. The highly accelerated jet occurred in the active region NOAA 10960 on 2007 June 5. Multi-wavelength spectral observations with EIS/Hinode allow us to investigate Doppler velocities at the wide temperature range. We analysed the three-dimensional angle of the jet from the stereoscopic analysis with STEREO. Using this angle and Doppler velocity, we derived the true velocity of the jet. As a result, we found that the cool jet observed with {He}{2} 256 \AA \log_{10}T_e[K] = 4.9 is accelerated to around 220 km/s which is over the upper limit of the chromospheric evaporation. The velocities observed with the other lines are under the upper limit of the chromospheric evaporation while most of the velocities of hot lines are higher than that of cool lines. We interpret that the chromospheric evaporation and magnetic acceleration occur simultaneously. A morphological interpretation of this event based on the reconnection model is given by utilising the multi-instrumental observations.
Since last writing, Sunspot 960 has let off two more serious flares (and a host of minor ones), including a powerful M7.4 flare. You can see the details of that flare here, and here is some of the STEREO imagery of that flare. Read more