{"id":84517,"date":"2025-01-31T13:02:58","date_gmt":"2025-01-31T12:02:58","guid":{"rendered":"https:\/\/wfa.uwr.edu.pl\/?p=84517"},"modified":"2025-01-31T13:03:04","modified_gmt":"2025-01-31T12:03:04","slug":"first-comparison-of-flarix-simulations-with-msdp-observation-of-the-c1-6-solar-flare-in-the-h-alpha-line-of-hydrogen","status":"publish","type":"post","link":"https:\/\/wfa.uwr.edu.pl\/en\/2025\/01\/31\/first-comparison-of-flarix-simulations-with-msdp-observation-of-the-c1-6-solar-flare-in-the-h-alpha-line-of-hydrogen\/","title":{"rendered":"First Comparison of FLARIX Simulations with MSDP Observation of the C1.6 Solar Flare in the H-alpha Line of Hydrogen"},"content":{"rendered":"

First Comparison of FLARIX Simulations with MSDP Observation of the C1.6 Solar Flare in the H-alpha Line of Hydrogen<\/h2>\n\n\n

Solar flares are the most dynamic active phenomena observed on the Sun. The large quantity of energy emitted during their emergence may not only influence changes in emissions of electromagnetic radiation from the Sun or cause eruptions of enormous amounts of solar plasma, but it may also have direct influence on the surroundings of Earth, its magnetic field and ionosphere.<\/p>\n\n\n\n

In the work discussed here, a flare emission analysis of the radiation emitted by the solar chromosphere in the H-alpha spectral line of hydrogen (656.3 nm) has been carried out using heliophysical observations as well as numerical modeling of the solar atmosphere heated by particle (electron) beams during the initial phase of the flare. For the analysis spectroscopic MSDP observations were used, made with very high temporal resolution (50 ms) at the Astronomical Observatory in Bia\u0142k\u00f3w (belonging to the Institute of Astronomy of the University of Wroc\u0142aw), as well as a time-dependent radial-hydrodynamic (RHD) model of the solar atmosphere FLARIX used by the research team led by prof. P. Heinzel from the Astronomical Institute of the Czech Academy of Sciences in Ond\u0159ejov – currently also employed at UWr, as part of the Incubator of Scientific Excellence \u2013 Activity of the Sun and Stars.<\/p>\n\n\n\n

\"rozb\u0142ysk\"
Fig. 1 An image of the analysed phenomenon obtained during the impulse phase of the C1.6 class flare on 10 September 2012 at 10:21:41,5 UT with a MSDP imaging spectrograph operating at the Astronomical Observatory of the University of Wroc\u0142aw (branch in Bia\u0142k\u00f3w). The image presents a flare emission at the centre of the H-alpha spectral line of hydrogen (656.3 nm). The black square marks the localization of measurement of the profile of the H-alpha line of hydrogen (the brightest part of the flare) while the black frame indicates the localization where the \u201cactivated MSDP\u201d profile was measured. Both squares match in size the respective pixels of the MSDP image. The size of a pixel is 1.6 x 1.6 arc seconds (i.e. about 1600 x 1600 km on the Sun). In the upper left corner a line segment of 5 arc seconds in length (i.e. about 3600 km on the Sun) is presented. The north direction (on the solar disc) is marked with a white arrow in the upper right corner.<\/em><\/figcaption><\/figure>\n\n\n\n

For the first time it was possible to combine modeling with the FLARIX code (based on the parameters of a real, specific solar flare) with spectroscopic observations of this flare made at the observatory in Bia\u0142k\u00f3w. For the purpose of modeling rapid (sub-second) emission changes during the initial phase of a flare an innovative method of modulating the parameters of electron beams, obtained from 4-second X-ray spectra (from the RHESSI satellite) for sub-second time resolutions, was used.<\/p>\n\n\n\n

\"rozb\u0142ysk\"
Fig. 2 Evolution of the profile of the H-alpha spectral line of hydrogen obtained from the FLARIX model (left panel) and from the observations made with the MSDP imaging spectrograph (right panel) for the analysed solar flare. Different colors represent chosen profiles of the line registered during the impulse phase of the flare at various time intervals. A fill factor of FF = 0.20 was used for the model profiles. The dashed line presents pre-flare profiles while the dotted line shows the profiles of the quiescent (non-flash) chromosphere – a synthetic profile taken from the VAL-C model with a microturbulence equal to 6 km\/s. The modeling included a microturbulence of 16 km\/s and a position on the solar disk like that of the observed flare (\u03bc = 0.56).<\/em><\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

The observed and synthetic (numeric) changes in the flare\u2019s brightness during the impulse phase were consistent (save for minor deviations). Taking into consideration an extra factor – the so-called fill factor (stemming among others from the limited spatial resolution of the observation), the flare profiles of the H-alpha spectral line of hydrogen obtained from modeling also coincided well with changes in observed profiles. The paper also includes a detailed discussion of factors that may affect the differences that occur between numerical models of the solar atmosphere and actual observations.<\/p>\n\n\n\n

The paper titled First Comparison of FLARIX Simulations with MSDP Observation of the C1.6 Solar Flare in the H-alpha Line of Hydrogen<\/em> by: Radziszewski K., Heinzel P., Ka\u0161parov\u00e1 J., Litwicka M., Berlicki A., Rudawy P., Falewicz R. was published in the Astrophysical Journal 2024, 977, 132<\/p>\n\n\n

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