Related papers: How reliable is Zeeman Doppler Imaging without sim…
A big challenge in solar and stellar physics in the coming years will be to decipher the magnetism of the solar outer atmosphere (chromosphere and corona) along with its dynamic coupling with the magnetic fields of the underlying…
Spectropolarimetric inversions are routinely used in the field of Solar Physics for the extraction of physical information from observations. The application to two-dimensional fields of view often requires the use of supercomputers with…
New determinations of effective temperatures of 23 magnetic, chemically peculiar (mCP) stars were obtained from a fit of metal enhanced model atmospheres to the observed spectral energy distributions (SED) from UV to red. The…
Low-mass stars are known to have magnetic fields that are believed to be of dynamo origin. Two complementary techniques are principally used to characterise them. Zeeman-Doppler imaging (ZDI) can determine the geometry of the large-scale…
Starspots are ubiquitous in young, low-mass stars, yet their impact on the spectral classification and fundamental parameter inference of pre-main sequence stars (PMS) has been largely overlooked. In this study, we demonstrate that cool…
Observational constraints on stellar magnetic fields are essential to both stellar and planetary physics. Recent studies revealed the diversity and evolution of large-scale magnetic fields in low-mass stars. These large-scale fields only…
Spectral inversion codes are powerful tools to analyze spectropolarimetric observations, and they provide important diagnostics of solar magnetic fields. Inversion codes differ by numerical procedures, approximations of the atmospheric…
We use cosmological hydrodynamical simulations to assess the feasibility of constraining the thermal history of the intergalactic medium during reionisation with the Ly$\alpha$ forest at $z\simeq5$. The integrated thermal history has a…
We present test results on the simultaneous inversion of the Stokes profiles of the He I lines at 587.6 nm (D_3) and 1083.0 nm in prominences (90-deg scattering). We created datasets of synthetic Stokes profiles for the case of quiescent…
We present a new approach for correcting instrumental polarization by modeling the non-depolarizing effects of a complex series of optical elements to determine physically realizable Mueller matrices. Provided that the Mueller matrix of the…
Aims: We present a magnetic Doppler imaging study from all Stokes parameters of the cool, chemically peculiar star HD 24712. This is the very first such analysis performed at a resolving power exceeding 10^5. Methods: The analysis is…
The derivation of the effective temperature of a star is a critical first step in a detailed spectroscopic analysis. Spectroscopic methods suffer from systematic errors related to model simplifications. Photometric methods may be more…
We present a technique that combines Zeeman Doppler imaging (ZDI) principles with a potential field mapping prescription in order to gain more information about the surface field topology of rapid rotators. This technique is an improvement…
Magnetic fields and mass accretion processes create dark and bright spots on the surface of young stars. These spots manifest as surface thermal inhomogeneities, which alter the global temperature measured on the stars. To understand the…
AIMS :The thermodynamic and magnetic field structure of the solar photosphere is analyzed by means of a novel 3-dimensional spectropolarimetric inversion and reconstruction technique. METHODS : On the basis of high-resolution,…
Spatially resolved studies of star forming regions show that the assumption of spherical geometry is not realistic in most cases, with a major complication posed by the gas being ionised by multiple non-centrally located stars or star…
In a previous paper, we argued that the inversion of Stokes profiles applied to spectropolarimetric observations of the solar internetwork yield unrealistically large values of the inclination of the magnetic field vector ($\gamma$). This…
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…
Stellar dynamo processes can be explored by measuring the magnetic field. This is usually obtained using the atomic and molecular Zeeman effect in spectral lines. While the atomic Zeeman effect can only access warmer regions, the use of…
We show that high-resolution observations of resolved Zeeman split lines can be used to obtain new constraints on the stellar magnetic field geometry. In particular, the contrast of the field strength distribution over the stellar surface…