Related papers: Multiline Zeeman Signatures Through Line Addition
Magnetism is one of the most important forces on the interstellar medium (ISM), anisotropically regulating the structure and star formation that drive galactic evolution. Recent high dynamic range observations of diffuse gas and molecular…
All magnetic field vector measurements lead to ambiguous results. We show that observations in two different lines belonging to the same multiplet but having different absorption coefficients so that they are formed at two different depths…
We highlight the main results of a radiative transfer investigation on the magnetic sensitivity of the solar Mg ii k resonance line at 2795.5 angstrom, accounting for the joint action of the Hanle and Zeeman effects as well as partial…
Late-type stars in general possess complicated magnetic surface fields which makes their detection and in particular their modeling and reconstruction challenging. In this work we present a new Zeeman-Doppler imaging code which is…
Although significant progress has been achieved in recent surveys of the magnetism in massive stars, the origin of the detected magnetic fields remains to be the least understood topic in their studies. We present an analysis of 61…
The only way to obtain reliable empirical information on the intensity and topology of the weak magnetic fields of the quiet solar chromosphere is via the measurement and rigorous physical interpretation of polarization signals in…
Measurements of interplanetary magnetic fields have long relied on spacecraft measurements, which provide only in-situ sampling and therefore cannot capture the global magnetic structure. Faraday rotation of radio signals extends in-situ…
Direct measurements of magnetic fields in low-mass stars of spectral class M have become available during the last years. This contribution summarizes the data available on direct magnetic measurements in M dwarfs from Zeeman analysis in…
M dwarfs host strong magnetic fields that can be measured using several complementary techniques. However, the impact of key methodological choices on Zeeman broadening diagnostics has not been systematically quantified. We assess the…
Approximately 7% of massive stars host stable surface magnetic fields that are strong enough to alter stellar evolution through their effect on the stellar wind. It is therefore crucial to characterize the strength and structure of these…
Direct measurements of the stellar magnetic fields are based on the splitting of spectral lines into polarized Zeeman components. With few exceptions, Zeeman signatures are hidden in data noise and a number of methods have been developed to…
Given that dynamically significant magnetic fields in at least some massive stars have now been measured, our contribution addresses the question, to what extent can fields be directly detected in circumstellar gas? The question speaks…
In this chapter, we give a brief introduction into the use of the Zeeman effect in astronomy and the general detection of magnetic fields in stars, concentrating on the use of FORS2 for longitudinal magnetic field measurements.
The relationship between the magnetic field and the circular polarization of astrophysical maser radiation due to the Zeeman effect under idealized conditions is investigated when the Zeeman splitting is much smaller than the spectral…
Magnetic fields play important roles in many astrophysical processes. However, there is no universal diagnostic for the magnetic fields in the interstellar medium (ISM) and each magnetic tracer has its limitation. Any new detection method…
An extremely weak circularly-polarized signature was recently discovered in spectral lines of the chemically peculiar Am star Sirius A (Petit et al. 2011). This signal was interpreted as a Zeeman signature related to a sub-gauss…
Modelling of the spectra of magnetic A and B main sequence stars is generally done assuming that all the lines are split by the magnetic field according to the Zeeman effect. However, a number of prominent spectral lines are produced by…
An extremely weak circularly polarized signature was recently discovered in spectral lines of the chemically peculiar Am star Sirius A. A weak surface magnetic field was proposed to account for the observed polarized signal, but the shape…
Due to the quick evolution of the solar chromosphere, its magnetic field cannot be inferred reliably without accounting for the temporal variations of its polarized light. This has been broadly overlooked in the modelling and interpretation…
We show a selection of high-sensitivity spectropolarimetric observations obtained over the last few years in the Ba II D2-line with the Zurich Imaging Polarimeter (ZIMPOL) attached to the Gregory Coude Telescope of IRSOL. The measurements…