| Presenter: | Nataliya Shchukina |
| Affiliation: | Main Astronomical Observatory, National Academy of Sciences, Ukraine |
| Title: | Three-dimensional radiative transfer modeling of the Second Solar Spectrum of titanium |
| Authors: | N.G. Shchukina, J. Trujillo Bueno |
| Form: | talk |
| Abstract: | The Second Solar Spectrum of neutral titanium shows a variety of conspicuous linear polarization signals whose understanding needs the consideration of realistic atomic and atmospheric models. In particular, the 13 spectral lines of one of the multiplets of neutral titanium seem to be ideal for investigating the Sun's hidden magnetism via the differential Hanle effect (Manso Sainz, Landi Degl'Innocenti \& Trujillo Bueno 2004). Our scientific goal is the empirical investigation of the elusive magnetism of the quiet Sun via the Hanle and Zeeman effects in suitably chosen spectral lines. Our first step towards a reliable diagnostics has been to pave the way by carefully investigating the physics of formation of the titanium spectrum in ``realistic'' 3D hydrodynamical models of the solar atmosphere. The second step has been to carry out a careful investigation of the unmagnetized reference case, paying particular attention to the Ti~{\sc{i}} ${\lambda}4536$ line because this line is completely immune to the Hanle and Zeeman effects. Therefore, if the chosen 3D reference atmospheric model is truly realistic, and if the collisional rates we are using are sufficiently accurate, one should then find agreement between the calculated and observed scattering polarization amplitudes. Finally, we allow for the presence of a microturbulent magnetic field in order to investigate whether its inclusion leads to a good agreement with Gandorfer's (2000, 2002) observations. The results of our multilevel radiative transfer calculations are also of interest in the field of quantitative stellar spectroscopy, with emphasis on the determination of chemical abundances. |
| Session: | 4. Polarized radiative transfer, theory and modeling |
| Presentation date: | Tuesday 18th September |
| Presentation time: | 16:00:00 |