Radiative accelerations on carbon, nitrogen and oxygen - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 1995

Radiative accelerations on carbon, nitrogen and oxygen

Résumé

Radiative accelerations acting on the elements carbon, nitrogen and oxygen are calculated over a large range of plasma parameters which covers the conditions of A-F star envelopes. The theoretical atomic data available from the OPACITY project (OP) have been extensively used to perform a detailed computation of radiative accelerations including the contribution of lines and photoionization for all ions of C, N and O. The present calculations apply the method developed in a recent related paper. It includes several improvements by comparison with the usual approximations adopted previously, in particular concerning the background opacity, the pressure broadening of lines, and the distribution of radiative acceleration between adjacent ions after photoabsorption. Results are presented for models of stellar envelopes with effective temperatures ranging between 6700 and 10000K. For each of the elements C, N, and O, the variation of the radiative acceleration through the envelope is obtained for 19 different abundances. A parameterization of these results is attempted, using a simple formula which gives the radiative acceleration, as a function of only two parameters for each ion. These parameters do not depend on plasma conditions. A greater accuracy of about 0.2 dex is possible by simple interpolation in the available tables of results. The radiative accelerations obtained for C, N, and O are used to estimate the equilibrium abundances of these elements in A and F-type stars, and the comparison with available observed abundances is discussed.
Fichier principal
Vignette du fichier
1995A&A...302..788G.pdf (312.88 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Licence : CC BY - Paternité

Dates et versions

hal-03985557 , version 1 (13-02-2023)

Licence

Paternité

Identifiants

  • HAL Id : hal-03985557 , version 1

Citer

Jean-François Gonzalez, Marie-Christine Artru, Georges Michaud. Radiative accelerations on carbon, nitrogen and oxygen. Astronomy and Astrophysics - A&A, 1995, 302, pp.788-796. ⟨hal-03985557⟩
13 Consultations
10 Téléchargements

Partager

Gmail Facebook X LinkedIn More