# Three-dimensional abundance distributions in ApBp star atmospheres: non-axisymmetric magnetic geometry

## TL;DR

This paper introduces a pioneering 3D model of ApBp star atmospheres with non-axisymmetric magnetic fields, revealing complex, three-dimensional abundance patterns that challenge previous simplified ring-like structures.

## Contribution

It presents the first 3D atomic diffusion model for ApBp stars with non-axisymmetric magnetic geometries, advancing beyond the centered dipole assumptions.

## Key findings

- Elements form complex 3D abundance patterns
- Magnetic geometry significantly influences element distribution
- Results challenge simplified ring-like abundance structures

## Abstract

Numerical models for the atmospheres of magnetic ApBp stars have in the past dealt only with centred dipole magnetic field geometries. These models include atomic diffusion that stratifies the abundances of metals according to the local magnetic field strength and the direction with respect to the surface normal. The magnetic variations with rotational phase of most well observed stars however reveal that this assumption is far too simplistic. In this work we establish for the first time a three-dimensional (3D) model with abundance stratifications arising from atomic diffusion of 16 metals, adopting a non-axisymmetric magnetic field geometry inspired by the configuration derived for a real ApBp star. We find that the chemical elements are distributed in complex patterns in all three dimensions, far from the simple rings that have been proposed as the dominant abundance structures from calculations that assume a perfectly centred dipolar magnetic geometry