Model estimates of inelastic calcium-hydrogen collision data for non-LTE stellar atmospheres modeling

Abstract : Aims. Inelastic processes in low-energy Ca + H and Ca+ + H- collisions are treated for the states from the ground state up to the ionic state with the aim to provide rate coeffcients needed for non-LTE modeling of Ca in cool stellar atmospheres. Methods. The electronic molecular structure was determined using a recently proposed model approach that is based on an asymptotic method. Nonadiabatic nuclear dynamics were treated by means of multichannel formulas, based on the Landau-Zener model for nonadiabatic transition probabilities. Results. The cross sections and rate coeffcients for inelastic processes in Ca + H and Ca+ + H- collisions were calculated for all transitions between 17 low-lying covalent states plus the ionic state. It is shown that the highest rate coeffcient values correspond to the excitation, de-excitation, ion-pair formation, and mutual neutralization processes involving the Ca(4s5s 1;3S) and the ionic Ca+ + H- states. The next group with the second highest rate coeffcients includes the processes involving the Ca(4s5p 1;3P), Ca(4s4d 1;3D), and Ca(4s4p 1P) states. The processes from these two groups are likely to be important for non-LTE modeling.
Type de document :
Article dans une revue
Astronomy and Astrophysics - A&A, EDP Sciences, 2016, 587 (16), pp.3646 - 3653. 〈10.1051/0004-6361/201527651〉
Liste complète des métadonnées

https://hal-upec-upem.archives-ouvertes.fr/hal-01432745
Contributeur : Alexander Mitrushchenkov <>
Soumis le : jeudi 12 janvier 2017 - 09:33:27
Dernière modification le : samedi 9 juin 2018 - 15:10:01

Lien texte intégral

Identifiants

Collections

Citation

A. Belyaev, A. Yakovleva, M. Guitou, A. Mitrushchenkov, A. Spielfiedel, et al.. Model estimates of inelastic calcium-hydrogen collision data for non-LTE stellar atmospheres modeling. Astronomy and Astrophysics - A&A, EDP Sciences, 2016, 587 (16), pp.3646 - 3653. 〈10.1051/0004-6361/201527651〉. 〈hal-01432745〉

Partager

Métriques

Consultations de la notice

120