Abstracts Details


First Name * : Akiko
Last Name * : Tei
Affiliation * : Kyoto University
Abstract Type * : Invited
Title * : Observations and modeling of chromospheric lines during a solar flare
Author(s) * : Akiko TEI, Jana KASPAROVA, Petr HEINZEL, Kazunari SHIBATA, Tatsuki NAKAMURA, Joten OKAMOTO, Takahito SAKAUE, Tomoko KAWATE, Ayumi ASAI, Satoru UENO, Kiyoshi ICHIMOTO
Abstract Session * : Solar flares and coronal mass ejections
Abstract * : During the coordinated observations of NOAA AR 12205 with the Interface Region Imaging Spectrograph (IRIS) and the Domeless Solar Telescope (DST) at Hida Observatory, we observed a C-class flare on November 11, 2014. We investigated the temporal and spatial evolution around a moving flare kernel, using the spectral data in the Si IV 1403 A, C II 1335 A, and Mg II h and k lines from IRIS and the Ca II K, Ca II 8542 A, and H-alpha lines from DST. In the Mg II h line, the leading edge of the kernel showed intensity enhancement in the blue wing and asymmetry between the blue-side peak and red-side one. Then, the drastic change of the intensity in the red wing occurred. The blueshift lasted for 9–48 s with a speed of about 10 km/s and it was followed by the strong redshift with a speed of up to 50 km/s detected in the Mg II h line. The strong redshift was a common property for all six lines but the blueshift prior to it was found only in the Mg II lines. A cloud modeling of the Mg II h line suggests that the blue wing enhancement, together with the peak asymmetry, can be caused by a cool chromospheric upflow. We attempt to model the evolution of the chromospheric lines during the impulsive phase of the flare, using the non-LTE radiation-hydrodynamics code FLARIX. We discuss the formation of a cool upflow in the flaring atmosphere which is heated by a non-thermal electron beams and show its influence on the chromospheric lines.