Related papers: A 3D Radiative Transfer Code for Modeling the Hanl…
Magnetic field measurements in the upper chromosphere and above, where the gas-to-magnetic pressure ratio $\beta$ is lower than unity, are essential for understanding the thermal structure and dynamical activity of the solar atmosphere.…
Context. Magnetic fields are important to the dynamics of many astrophysical processes and can typically be studied through polarization observations. Polarimetric interferometry capabilities of modern (sub)millimeter telescope facilities…
This paper addresses the problem of scattering line polarization and the Hanle effect in one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) media for the case of a two-level model atom without lower-level polarization and…
Radiative transfer (RT) studies of the linearly polarized spectrum of the Sun (the second solar spectrum) have generally focused on the line formation, with an aim to understand the vertical structure of the solar atmosphere using…
The linear polarization pattern produced by scattering processes in the Ca I resonance line at 4227 angstroms is a valuable observable for probing the solar atmosphere. Via the Hanle effect, the very significant Q/I and U/I line-center…
The interpretation of the intensity and polarization of the spectral line radiation produced in the atmosphere of the Sun and of other stars requires solving a radiative transfer problem that can be very complex, especially when the main…
Here we formulate and solve the 3D radiative transfer problem of the polarization of the solar continuous radiation. Our approach takes into account not only the anisotropy of the continuum radiation, but also the symmetry-breaking effects…
In the previous two papers, namely, \citet{anuknn11} and \citet{anuetal11} we solved the polarized radiative transfer (RT) equation in multi-dimensional (multi-D) geometries, with partial frequency redistribution (PRD) as the scattering…
The bulk of the quiet solar photosphere is thought to be significantly magnetized, due to the ubiquitous presence of a tangled magnetic field at subresolution scales with an average strength <B> ~ 100 G. This conclusion was reached through…
Although the h and k lines of MgII are expected to be of great interest for probing the upper solar chromosphere, relatively little is known about their polarization properties which encode the information on the magnetic field. Here we…
The chromosphere of the quiet Sun is an important stellar atmospheric region whose thermal and magnetic structure we need to decipher for unlocking new discoveries in solar and stellar physics. To this end, we must identify and exploit…
Aims: The polarization of the Ca II resonant doublet (H and K lines) and the subordinate infrared triplet lines are key observables for diagnosing solar chromospheric magnetism. It is thus necessary to understand the physical mechanisms…
Scattering polarization tends to dominate the linear polarization signals of the Ca II 8542 A line in weakly magnetized areas ($B \lesssim 100$ G), especially when the observing geometry is close to the limb. In this paper we evaluate the…
The main goal of this thesis has been to investigate the effects that the macroscopic vertical velocity fields have on the scattering polarization signals formed in the solar chromosphere. Until now, the impact of macroscopic motions had…
Our understanding of coronal phenomena, such as coronal plasma thermodynamics, faces a major handicap caused by missing coronal magnetic field measurements. Several lines in the UV wavelength range present suitable sensitivity to determine…
The diagnostic capabilities of spectral lines in far ultraviolet (FUV) and extreme ultraviolet (EUV) wavelength range are explored in terms of their Hanle and Zeeman sensitivity to probe vector magnetic field in the solar corona. The…
We highlight the main results of a three-dimensional (3D) multilevel radiative transfer investigation about the solar disk-center polarization of the Ca {\sc ii} 8542 \AA\ line. First, we investigate the linear polarization due to the…
Lyman-$\alpha$ (Ly$\alpha$) is a powerful astrophysical probe. Not only is it ubiquitous at high redshifts, it is also a resonant line, making Ly$\alpha$ photons scatter. This scattering process depends on the physical conditions of the gas…
Most of the quantitative information about the magnetic field vector in solar prominences comes from the analysis of the Hanle effect acting on lines formed by scattering. As these lines can be of non-negligible optical thickness, it is of…
Emission features formed through Raman scattering with atomic hydrogen provide unique and crucial information to probe the distribution and kinematics of a thick neutral region illuminated by a strong far UV emission source. We introduce a…