Publications (26)
Polarization diagnostics of proton beams in solar flares
Jiri Stepan
We review the problem of proton beam bombardment of solar chromosphere considering the self-consistent NLTE polarized radiation transfer in hydrogen lines. Several observations ind…
Generalized sqrt(epsilon)-law. The role of unphysical source terms in resonance line polarization transfer and its importance as an additional test of NLTE radiative transfer codes
Jiri Stepan, Veronique Bommier
Context. A derivation of a generalized sqrt(epsilon)-law for nonthermal collisional rates of excitation by charged perturbers is presented. Aims. Aim of this paper is to find a mor…
Near optimal angular quadratures for polarised radiative transfer
Jiri Stepan, Jaume Jaume Bestard, Javier Trujillo Bueno
In three-dimensional (3D) radiative transfer (RT) problems, the tensor product quadratures are generally not optimal in terms of the number of discrete ray directions needed for a…
Comparison of theoretical and observed Ca~{\sc ii}~8542 Stokes profiles in quiet regions at the centre of the solar disc
Jan Jurcak, Jiri Stepan, Javier Trujillo Bueno +1
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…
Evaluating the reliability of a simple method to map the magnetic field azimuth in the solar chromosphere
Jan Jurcak, Jiri Stepan, Javier Trujillo Bueno
The Zeeman effect is of limited utility for probing the magnetism of the quiet solar chromosphere. The Hanle effect in some spectral lines is sensitive to such magnetism, but the i…
The uncertainty of magnetic fields in 3D non-local thermodynamic equilibrium inversions
Jiri Stepan, Tanausu del Pino Aleman, Andres Vicente Arevalo
We describe our approach to solve the problem of ensuring the solenoidality of the magnetic field vector in three-dimensional (3D) inversions, as well as the estimation of the unce…