C50

Presentation Title: Investigation of co-temporal IRIS and SolO/STIX observations of the solar flare.
Author(s): Michalina Litwicka, Arkadiusz Berlicki, Petr Heinzel

Abstract:

STIX onboard Solar Orbiter (SolO) continous observation since 2020 gives us acces to high quality X-ray data. Together with IRIS UV spectrograph we are able to see solar flares in very broad spectral range which allows us to test some physics behind this events. One of the STIX’s advantage is orbit around the Sun with distance much less than 1 AU for most of the time. At the same time it is challenging to find common flare observation with Earh-orbiting satellites. Since 2020 there was only a few months during which SolO observed the Sun from close-to-Earth perspective. We found couple of flares observed by SolO and IRIS, from which we chose two for further analysis. Using data from STIX, Full Sun Imager (FSI) from Extreme-UV Imager (EUI) onboard SolO, AIA (SDO) and IRIS we were able to study and compare emission during flare time in near-UV spectral range (Mg II h and k, IRIS), far-UV (SI IV, C II, IRIS), in extreme UV channels (SDO, FSI) and in X-ray emission (SolO, STIX), in the range of 4-150 keV. We located X-ray source on IRIS slit-jaw images, specified source size and its other patameters. Using OSPEX software we made spectral fitting using a standard combination of thermal (f_vth) and non-thermal (f_thick2) functions, in order to determine parameters referring to thermal and non-thermal spectrum component. Finally, we make first step in flare modeling using hybrid radiation-hydrodynamical, numerical code FLARIX, in order to calculate synthetic Mg II h and k spectra evolution and make comparison with IRIS Mg II h and k observation.