Improvements in the Mg I atomic model for solar and stellar atmospheric models

D. M. MITNIK; JUAN I. PERALTA; M. C. VIEYTES; M. P. A. MENDEZ

San Martín

Workshop; EXO.AR I - 1st Argentinian Workshop on Exoplanets ?Observations and data analysis?; 2017

International Center for Advanced Studies (ICAS) and National University of San Martín

Given the relevance of the spectral features formed by Mg I in the stellar spectrum of late type stars, we present a new atomic model to be implemented in the Solar Stellar Radiation Physical Modeling (SSRPM) models of the solar and stellar atmosphere. The improvements that we performed are listed next: * The number of energy levels (and sublevels) in the atomic model were increased from 26 (3s.5g) to 45 (3s.8p)* For each energy level of the atom included in the model, the effective collision strengths for electron impact excitation (EIE) were calculated using R-matrix method.* The broadening parameters for each line of Mg I were updated. The Radiative Damping parameter was calculated from the Einstein coefficient, provided by R-matrix. The Stark and Vander Waals coefficients were updated with current data from Kurucz database (Kurucz, 08/2017).We computed the populations of the Mg I in full NLTE using the SSRPM code for a semiempirical model of the magnetic network for the quiet Sun. Then we computed the emitted spectrum to test relevant changes in the formation of some of the most important Mg I features. In order to make clear comparisons, previous models and solar observations were plotted overlapped.