Related papers: iota Cas: Multi-element Doppler imaging and magnet…
Magnetic A stars represent about $5\%$ of the upper main sequence stars and exhibit highly ordered, very stable and often very strong magnetic fields. They frequently show both, brightness- and spectral line profile variations synchronised…
Doppler imaging, a technique which inverts spectral line profile variations of an Ap star into a two-dimensional abundance maps, provides new observational constraints on diffusion mechanism in the presence of a global magnetic field. A…
Magnetic Doppler imaging is currently the most powerful method of interpreting high-resolution spectropolarimetric observations of stars. This technique has revealed the presence of unexpected small-scale magnetic fields on the surfaces of…
In recent papers convincing evidence has been presented for chemical stratification in Ap star atmospheres, and surface abundance maps have been shown to correlate with the magnetic field direction. Radiatively driven diffusion in magnetic…
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…
New observational techniques and sophisticated modelling methods has led to dramatic breakthroughs in our understanding of the interplay between the surface magnetism, atomic diffusion and atmospheric dynamics in chemically peculiar stars.…
Magnetic perturbations to the frequencies of low degree, high radial order, axisymmetric pulsations in stellar models permeated by large scale magnetic fields are presented. Magnetic fields with dipolar, quadrupolar and a superposition of…
Historically, the magnetic field geometries of the chemically peculiar Ap stars were modelled in the context of a simple dipole field. However, with the acquisition of increasingly sophisticated diagnostic data, it has become clear that the…
We present the first magnetic Doppler images of a rapidly oscillating Ap (roAp) star. We deduce information about magnetic field geometry and abundance distributions of a number of chemical elements on the surface of the hitherto best…
The upper main sequence magnetic chemically peculiar (Ap) stars exhibit a non-uniform distribution of chemical elements across their surfaces and with height in their atmospheres. These inhomogeneities, responsible for the conspicuous…
An arbitrary initial magnetic field in an A star evolves into a stable equilibrium. Simulations are presented of the formation of non-axisymmetric equilibria consisting of twisted flux tubes meandering under the surface of the star, and…
High time resolution spectroscopy of roAp stars at large telescopes has led to a major breakthrough in our understanding of magnetoacoustic pulsations in these interesting objects. New observations have allowed to uncover a number of…
Stars with radiative envelopes, specifically the upper main sequence chemically peculiar (Ap) stars, were among the first objects outside our solar system for which surface magnetic fields have been detected. Currently magnetic Ap stars…
Context. See abstract in the paper. Aims. In the last paper of this series we study the effects of the magnetic field, varying its strength and orientation, on the model atmosphere structure, the energy distribution, photometric colors and…
Rapidly oscillating Ap stars exhibit an astrophysically interesting combination of strong, dipolar-like magnetic fields and high-overtone p-mode pulsations similar to the Sun. Recent time-resolved spectroscopy of these stars unravelled a…
We perform three-dimensional numerical simulations of stellar winds of early-M dwarf stars. Our simulations incorporate observationally reconstructed large-scale surface magnetic maps, suggesting that the complexity of the magnetic field…
Magnetic fields on hot stars can produce a variety of interesting effects on the velocity, density, and temperature structure in the winds from the stars. The fields can produce a longitudinal dependence of the mass flux, which would lead…
Magnetic fields are an important component of the interstellar medium (ISM) and exhibit strongly varying field strengths and a non-trivial correlation with the gas density. Its dynamical impact varies between individual regions of the ISM…
Magnetic fields play an important role in producing and modifying the photospheric chemical peculiarities of intermediate-mass main sequence stars. This article discusses the basic theory and methods of measurement used to detect and…
(Abridged) Context. Most massive stars are located in multiple stellar systems. Magnetic fields are believed to be essential in the accretion and ejection processes around single massive protostars. Aims. Our aim is to unveil the influence…