Related papers: Pervasive Linear Polarization Signals in the Quiet…
The magnetic topology of the solar photosphere in its quietest regions is hidden by the difficulties to disentangle magnetic flux through the resolution element from the field strength of unresolved structures. The observation of spectral…
The Hinode mission has revealed copious amounts of horizontal flux covering the quiet Sun. Local dynamo action has been proposed to explain the presence of this flux. We sought to test whether the quiet Sun flux detected by Hinode is due to…
We study the structure of the photospheric magnetic field of the quiet Sun by investigating weak spectro-polarimetric signals. We took a sequence of Stokes spectra of the Fe I 630.15 nm and 630.25 nm lines in a region of quiet Sun near the…
Some recent investigations of spectropolarimetric observations of the Zeeman effect in the Fe I lines at 630 nm carried out with the Hinode solar space telescope have concluded that the strength of the magnetic field vector in the…
We have studied the angular distribution of the magnetic field vector in the solar internetwork employing high-quality data (noise level $\sigma \approx 3\times 10^{-4}$ in units of the quiet-Sun intensity) at different latitudes recorded…
We employ the magnetic and velocity fields from turbulent dynamo simulations to synthesize the polarization of a typical photospheric line. The synthetic Stokes profiles have properties in common with those observed in the quiet Sun. The…
The morphology of circular polarisation profiles from solar spectropolarimetric observations encode information about the magnetic field strength, inclination, and line-of-sight velocity gradients. Previous studies used manual methods or…
Interpreting the Stokes profiles observed in quiet regions of the solar chromosphere is a challenging task. The Stokes Q and U profiles are dominated by the scattering polarisation and the Hanle effect, and these processes can only be…
We present a Stokes I, Q and U survey at 189 MHz with the Murchison Widefield Array 32-element prototype covering 2400 square degrees. The survey has a 15.6 arcmin angular resolution and achieves a noise level of 15 mJy/beam. We demonstrate…
High levels of horizontal magnetic flux have been reported in the quiet-Sun internetwork, often based on Stokes profile inversions. Here we introduce a new method for deducing the inclination of magnetic elements and use it to test magnetic…
It is now well established that the quiet Sun contains in total more magnetic flux than active regions and represents an important reservoir of magnetic energy. But the nature and evolution of these fields remain largely unknown. We…
Computing polarised intensities from noisy data in Stokes U and Q suffers from a positive bias that should be suppressed. To develop a correction method that, when applied to maps, should provide a distribution of polarised intensity that…
Polarimetric studies of pulsar radio emission traditionally concentrate on how the Stokes vector (I, Q, U, V) varies with pulse longitude, with special emphasis on the position angle (PA) swing of the linearly polarized component. The…
We analyze the spectral asymmetry of Stokes V (circularly polarized) profiles of an individual network patch in the quiet Sun observed by Sunrise/IMaX. At a spatial resolution of 0.15"-0.18", the network elements contain substructure which…
The existence of asymmetries in the circular polarization (Stokes V) profiles emerging from the solar photosphere is known since the 1970s. These profiles require the presence of a velocity gradient along the line of sight, possibly…
Scattering polarization in the Sr I 4607.3 \AA \ line observed with high resolution is an important diagnostic of the Sun's atmosphere and magnetism at small spatial scales. At present, spatially resolved observations of this diagnostic are…
Aims: Main goal of this work is to study the potential of He II Ly-alpha wavelength-integrated scattering polarisation for probing the magnetism of the solar upper chromosphere. Methods: Radiative transfer calculations are performed in…
The magnetic properties of the quiet Sun are investigated using a novel inversion code, FATIMA, based on the Principal Component Analysis of the observed Stokes profiles. The stability and relatively low noise sensitivity of this inversion…
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…
Our knowledge of the lower solar atmosphere is mainly obtained from spectropolarimetric observations, which are often carried out in the red or infrared spectral range and almost always cover only a single or a few spectral lines. Here we…