| Presenter: | Luca Belluzzi |
| Affiliation: | Dipartimento di Astronomia, Università degli Studi di Firenze |
| Title: | The linear polarization profile of the Li~{\sc i} 6707~{\AA} line as a diagnostic tool of the solar lithium isotopic abundance |
| Authors: | L. Belluzzi, E. Landi Degl'Innocenti, J. Trujillo Bueno |
| Form: | talk |
| Abstract: | The second solar spectrum offers a new formidable diagnostic window not only to explore the magnetic fields of our nearest star, but also to determine the isotopic abundances in the solar atmosphere. A very interesting example, concerning this second aspect, seems to be the Li~{\sc i} line at 6707~{\AA}, as already suggested by Stenflo \& Keller (1997). Here we present a detailed theoretical investigation, carried out within the framework of the density matrix formalism, on the physical origin of the observed $Q/I$ profile of this spectral line, which is the result of a complex blend of the D$_1$ and the D$_2$ lines of the stable isotopes of lithium ($^6$Li and $^7$Li, both showing hyperfine structure). We discuss the diagnostic potentialities of the linear polarization profile of this line for the determination of the quiet Sun lithium isotopic abundance, and we show how a deterministic or microturbulent magnetic field affects this profile. Theoretical results are compared with polarimetric observations, both in quiet regions close to the limb, and in not so quiet regions. |
| Session: | 2. Polarization physics in magnetized media |
| Presentation date: | Monday 17th September |
| Presentation time: | 16:15:00 |