3D distribution models of Ca, Cr, and Fe in a magnetic CP star atmosphere with anisotropic wind

• Published in: Monthly notices of the Royal Astronomical Society Vol. 504; no. 1; pp. 1370 - 1378
• Main Authors: Alecian, G, Stift, M J
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01-06-2021; Oxford University Press (OUP): Policy P - Oxford Open Option A
• Subjects: Sciences of the Universe; stars: mass-loss; diffusion; magnetic fields; stars: chemically peculiar; stars: abundances
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stab952

ABSTRACT
We present time-dependent atomic diffusion calculations for Ca, Cr, and Fe in a stellar magnetic atmosphere including an anisotropic wind. For three different models of mass-loss rates (or wind), we obtain a 3D description of the entire atmosphere. In two of these models, the mass-loss rate varies according to the magnetic field inclination, the assumed field geometry being non-axisymmetric. When the dipolar component of the magnetic field dominates, we find that ring-like abundance structures will be prominent. Spot-like distributions can also exist according to the field geometry. Abundance distributions turn out to be highly sensitive to the mass-loss model. The results are discussed and compared to an observational model of a real chemically peculiar star (θ Aurigae) that features parameters close to those of the model we have adopted for our calculations.