2010A&A...516A..53A

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. 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. We used our code CaratStrat to compute a large grid of stratifications (equilibrium solutions in LTE) for plane-parallel T_eff=8500, 10000, 12000, and 14000K stellar atmospheres. By interpolation, we constructed bi-dimensional cuts through these stellar atmospheres, which are permeated by a dipolar magnetic field of strength 20kG at the magnetic pole. We also provide vertical (1D) stratifications of metals in non-magnetic stars (HgMn). 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_eff=8500K model in the printed version, and compare it with stratifications derived from observed spectra.