Abundance distributions over the surfaces of magnetic ApBp stars: theoretical predictions

TL;DR

This paper presents theoretical predictions of chemical abundance distributions on magnetic ApBp stars' surfaces, aiming to reconcile differences with recent empirical maps obtained via Zeeman Doppler mapping.

Contribution

It introduces a comprehensive grid of equilibrium abundance stratifications for a magnetic Ap star, advancing the understanding of surface abundance patterns.

Findings

Predicted abundance patterns vary across the stellar surface.

The models highlight the influence of magnetic fields on element distribution.

Discrepancies with empirical maps suggest additional physical processes may be involved.

Abstract

Recently published empirical abundance maps, obtained through (Zeeman) Doppler mapping (ZDM), do not currently agree with the abundance structures predicted by means of numerical models of atomic diffusion in magnetic atmospheres of ApBp stars. In a first step towards the resolution of these discrepancies, we present a state of the art grid of equilibrium abundance stratifications in the atmosphere of a magnetic Ap star with T_eff = 10000 K and log g = 4.0. A description of the behaviour of 16 chemical elements including predictions concerning the over- and/or under-abundances over the stellar surface is followed by a discussion of the possible influence of presently neglected physical processes.