Impact of new atomic data for the formation of the Mg I b triplet lines in benchmark stars

Author:

Merle, T.   Thévenin, F.   Belyaev, A.K.   Guitou, M.   Feautrier, N.   Spielfiedel, A.   Zatsarinny, O.   Alecian, G.   Lebreton, Y.   Richard, O.   Vauclair, G.  

Journal:

EAS Publications Series

Issue Date:

2013

Abstract(summary):

We aim to improve the calculation of the Mg I line profiles in benchmark stars and to assess the impact of the new quantum mechanical calculations of inelastic collisions with hydrogen. The method is based on the non-Local Thermodynamic Equilibrium (NLTE) line formation using updated atomic data for a simple model atom of Mg I. Focus on the formation of the Mg I b triplet lines at 5167, 5172 and 5183 angstrom is presented for the Sun, Arcturus, HD 84937 (metal-poor dwarf) and HD 122563 (metal-poor giant). This study is preliminary and essentially tests the new atomic data. In this context, we show that NLTE effects are smaller for this triplet when quantum mechanical H collisions are included compared with the use of the semi-classical Drawin's formula.

Page:

331-336