Doppler Imaging of stellar magnetic fields. I. Techniques

  title={Doppler Imaging of stellar magnetic fields. I. Techniques},
  author={Nikolai Piskunov and Oleg Kochukhov},
  journal={Astronomy and Astrophysics},
We present an investigation of the magnetic field geometries and inhomogeneous distribution of chemical elements in the atmospheres of peculiar A and B stars. Our study combines high-quality spectroscopic and spectropolarimetric stellar observations with the development and application of novel techniques for theoretical interpretation of the shapes and variability of stellar line profiles. In particular, we extend the method of Doppler imaging to the analysis of spectra in the four Stokes… 
Magnetic Doppler imaging of 53 Camelopardalis in all four Stokes parameters
We present the first investigation of the structure of the stellar surface magnetic field using line profiles in all four Stokes parameters. We extract the information about the magnetic field
Doppler Imaging of stellar magnetic fields. III. Abundance distribution and magnetic field geometry of alpha 2 CVn
We used the new magnetic Doppler Imaging code to reconstruct the magnetic eld geometry and surface abundance distributions for the classical magnetic CP star 2 CVn. High-resolution
Magnetic Doppler imaging of the chemically peculiar star HD 125248
Intermediate-mass, chemically peculiar stars with strong magnetic fields give us an excellent opportunity to study the topology of their surface magnetic fields and the interplay between magnetic
Magnetic Doppler imaging of α2 Canum Venaticorum in all four Stokes parameters - Unveiling the hidden complexity of stellar magnetic fields
Context. Strong organized magnetic fields have been studied in the upper main sequence chemically peculiar stars for more than half a century. However, only recently have observational methods and
Magnetic field topology of the unique chemically peculiar star CU Virginis
Context. The late-B, magnetic, chemically peculiar star CU Vir is one of the fastest rotators among the intermediate-mass stars with strong fossil magnetic fields. It shows a prominent rotational
Magnetic Doppler imaging considering atmospheric structure modifications due to local abundances: a luxury or a necessity?
Magnetic Doppler imaging is currently the most powerful method of interpreting highresolution spectropolarimetric observations of stars. Th is technique has provided the very first maps of stellar
Doppler Imaging of stellar magnetic fields. II. Numerical experiments
We present numerical experiments designed to evaluate the performance of the new Magnetic Doppler Imaging (MDI) code INVERS10. Numerous test runs demonstrate what can be achieved with the MDI method
Magnetic field topology and chemical spot distributions in the extreme Ap star HD 75049
Intermediate-mass, magnetic chemically peculiar (Ap) stars provide a unique opportunity to study the topology of stellar magnetic fields in detail and to investigate magnetically driven processes of
Magnetic field topology and chemical spot distributions of the Ap star HD 119419
Context. Analysis of high-resolution spectropolarimetric time-series observations of early-type magnetic stars is currently the most advanced method of obtaining detailed information on their surface
Magnetic fields of M dwarfs
  • O. Kochukhov
  • Physics, Geology
    The Astronomy and Astrophysics Review
  • 2020
Magnetic fields play a fundamental role for interior and atmospheric properties of M dwarfs and greatly influence terrestrial planets orbiting in the habitable zones of these low-mass stars.


Magnetic cycles of HR 1099 and LQ Hydrae
We present in this paper a 6-yr time series of magnetic (and brightness) surface images of the K1 subgiant of the RS CVn system HR 1099 (=V711 Tauri) and of the young K0 dwarf LQ Hydrae,
Magnetic topology and prominence patterns on AB Doradus
We report new Zeeman--Doppler imaging observations of the rapidly rotating young K0 dwarf AB Doradus, obtained with the Anglo-Australian Telescope in 1996 December. From such observations,
An LTE Code for the Inversion of Stokes Spectra from Solar Magnetic Elements
We describe an LTE inversion code capable of inferring the thermal, magnetic and dynamic properties of unresolved magnetic elements. This information is obtained by fitting Stokes spectra observed in
Techniques for surface imaging of stars
Surface imaging of stars from the profiles of spectral lines, has become an important tool in modern astrophysics. It is presently used for mapping the distribution of chemical elements on Ap stars
Comparisons of images derived from independent Zeeman Doppler imaging codes
We compare surface brightness and magnetic field surface maps for the K0 dwarf AB Doradus, obtained using two independently developed Zeeman Doppler imaging codes. We find that even the fine
Solar Magnetism and the Second Solar Spectrum
The key to a unified understanding of the fundamental astrophysical building blocks, like magnetoturbulence, flux tubes, dynamo processes, and heating mechanisms, is to be found at the smallest
Non-LTE Inversion of Stokes Profiles Induced by the Zeeman Effect
This paper presents a new diagnostic tool for the inference of the thermal, dynamic, and magnetic properties of the solar chromosphere. It consists of a non-LTE inversion code of Stokes profiles
Stokes Profile Analysis and Vector Magnetic Fields. II. Formal Numerical Solutions of the Stokes Transfer Equations
Two numerical methods for formal integration of the Stokes transfer equations for line formation in a strong magnetic field were tested by computing Stokes profiles for a Zeeman triplet in a
Influence of magnetic fields on the coherence effects in the Nai D$\mathsf{_1}$ and D$\mathsf{_2}$ lines
To clarify the physical nature of the enigmatic scattering polarization in the Na i D 1 and D 2 line cores we have explored their behavior with full Stokes vector polarimetry in regions with varying
Numerical Radiative Transfer
Preface Introduction Part I. Operator Perturbation: 1. Survey of operator perturbation methods W. Kalkofen 2. Line formation in expanding atmospheres: multilevel calculations using approximate lambda