| Abstract * |
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Physics of the formation of hot plasma in the upper solar atmosphere has puzzled the astronomers since 1940s. Here we address the transient formation of hot plasma in the core of an active region using the observations recorded with the Interface Region Imaging Spectrograph (IRIS), Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). We have studied the evolution of the photospheric magnetic field using the line of sight (LOS) magnetograms taken by the Helioseismic and Magnetic Imager. Formation of a jet-like structure with a curved spire was observed in the slit-jaw images taken in Si IV, C II and Mg II. The jet is simultaneously observed in 1600~{\AA} and all the EUV channels of AIA. The complete evolution of the jet was observed on a time scale of 15 mins. The observation of the jet in all these channels suggests the multi-thermal nature of the plasma. Using the EUV data from AIA, we have performed a differential emission measure (DEM) analysis to study the temperature structure of the jet. Our results show that the highest emission from the base is within the temperature bin of log T = 6.65 to 6.95, whereas the spire show emission in much higher temperature bins. We further find that one of the footpoints of the base is located in the primary polarity, whereas the other is rooted in a parasitic polarity. We infer that the magnetic reconnection between the main flux region and the parasitic polarity causes this jet to form. Such multi-wavelength observations shed lights on the formation of hot plasma the solar corona. |
