Sep 10 Fri 14:30～16:00 Solar and Space Plasma Seminar Zoom
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9月16日（金）
Campus： Mitaka
Seminar： Solar and Space Plasma Seminar
Regularly Scheduled/Sporadic： Scheduled
Date and time：16th Sep (Fri), 14:30-16:00
Place： Zoom
Speaker：Vukadinovic Dusan
Affiliation：Max Planck Institute for Solar System Research
Title：
Investigating magnetic field inference from the spectral region around the Mg I b2 line using the weak-field approximation
The transition between plasma dominant photospheric region to a magnetically dominant chromospheric region happens around a temperature minimum. The structure of the magnetic fields in this region has not been studied in great detail since there are not many spectral lines that are forming at these heights. One example of spectral lines that originate from this region is the Mg I b triplet, where the b2 line has the strongest magnetic sensitivity of all three components and is free of blends. However, to properly model the b2 line profile we must treat it in the non-LTE regime which requires building an adequate atomic model for the magnesium atom. In this talk, we will go through the problem of constructing the atomic model, getting the correct ionization balance of the magnesium atom and properly synthesizing the b2 line. Afterwards, we will apply this atomic model to investigate how well is the line-of-sight magnetic field inferred from the b2 line using the weak-field approximation. We use spectra computed from the MURaM atmosphere of the quiet Sun to determine the line formation height and test the weak-field applicability.
Facilitator
-Name：Takayoshi oba
Comment：in English