Bi-dimensional element stratications computed for magnetic Ap star atmospheres

Autor(en)
Georges Alecian, Martin Stift
Abstrakt

Context. Theoretical modelling of abundance stratifications and surface distributions of chemical elements in Ap stars constitutes a major challenge. The atomic diffusion model provides the most appropriate framework in which to understand these abundance anomalies.
Aims. We present theoretical 2D stratifications of 16 metals in upper main sequence chemically peculiar stars, with and without magnetic fields to provide a reference point for further theoretical and observational studies.
Methods. We used our code CaratStrat to compute a large grid of stratifications (equilibrium solutions in LTE) for plane-parallel $T_{\rm eff}=8500$, 10 000, 12 000, and 14 000 K stellar atmospheres. By interpolation, we constructed bi-dimensional cuts through these stellar atmospheres, which are permeated by a dipolar magnetic field of strength 20 kG at the magnetic pole. We also provide vertical (1D) stratifications of metals in non-magnetic stars (HgMn).
Results. We present a large number of 2D and 1D stratifications, mostly as online material. We discuss in detail the case of Fe for the $T_{\rm eff}=8500$ K model in the printed version, and compare it with stratifications derived from observed spectra.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
Université Paris VII - Paris-Diderot
Journal
Astronomy & Astrophysics
Band
516
Anzahl der Seiten
17
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361/200913772
Publikationsdatum
06-2010
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/4886fbe6-18c4-4192-a325-901c4467cf9e