Astronomy and Astrophysics – Astrophysics
Scientific paper
Nov 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995a%26a...303..166l&link_type=abstract
Astronomy and Astrophysics, v.303, p.166
Astronomy and Astrophysics
Astrophysics
19
Atomic Processes, Diffusion, Radiative Transfer, Stars: Abundances, Stars: Chemically Peculiar
Scientific paper
Radiative accelerations have been calculated for all states of ionization of iron (I to XXVI) using the data of the Opacity Project and the Kurucz data bank. Both the bound-bound and the bound-free transitions have been included. Improvements have been made to line broadening, the continuum opacity and the distribution of the momentum to various states of ionization. Detailed results are presented for three Fe abundances in models with T_eff_=6700, 8000 and 10000K and logg=4.2. The effects of changing gravity and of the settling of He are discussed. Results obtained with the Kurucz and Opacity Project data are compared. Gravity and the radiative acceleration on Fe are always, for a solar Fe abundance, within a factor of about 3 of each other in stellar interiors of main sequence stars so that the under or over abundances are not expected to be very large. They should be limited to at most factors of 10 by the increase or reduction of saturation. This is however sufficient to affect stellar structure and the calculated radiative accelerations will be used to calculate evolutionary models taking into account the atomic diffusion of Fe as well, as of the other main contributors, to the Rosseland opacity. To this end the results are presented both in the form of approximate formulae and of tables which may be interpolated in evolutionary calculations. A comparison of the maximum amount of Fe that can be supported in the convection zone of AmFm stars with the results of Burkhart and Coupry shows that the two are consistent within the uncertainties brought by the neglect of evolutionary effects and of the effect of the settling of He and CNO. These can only be properly taken into account in detailed evolutionary calculations.
LeBlanc Francis
Michaud Georges
No associations
LandOfFree
Radiative accelerations on iron. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Radiative accelerations on iron., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radiative accelerations on iron. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1177571