Active region transition region loop populations and their relationship to the corona

摘要: The relationships among coronal loop structures at different temperatures is not settled. Previous studies have suggested that loops in the core of an active region are seen cooling through lower and therefore steadily heated. If were cooling, transition would be ideal temperature regime to look for a signature their evolution. Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode provides monochromatic images solar corona unprecedented cadence spatial resolution, making it instrument shed light this issue. Analysis observations 10978 taken 2007 December 8 -- 19 indicates there two dominant populations region: multi-temperature undergo continuous process heating full observed range 0.4-2.5 MK even higher as shown by X-Ray Telescope (XRT); peripheral which evolve mostly 0.4-1.3 MK. Loops can reach heights 150 Mm above limb develop downflows with velocities 39-105 km/s.