Aims: We aim to investigate the validity of the weak field approximation (WFA) for determining magnetic fields in quiet regions of the solar photosphere using...

We solve the line transfer problem in evolving H ii regions in order to calculate line profiles of hydrogen recombination (Hα) and forbidden oxygen ([O III]...

The effect of scattering processes in the continuum on the formation of spectral lines in a static atmosphere with an arbitrary distribution of the internal...

The numerical solution of the idealized, but self-consistent, LTE atmosphere problem posed by the authors has been used to introduce the effect of multiple...

The sizable linear polarization signals produced by the scattering of anisotropic radiation in the core of the Ca I 4227 Å line constitute an important...

The contribution of stars in galaxies to cosmic reionization depends on the star formation history in the Universe, the abundance of galaxies during...

Protogalaxies forming in low-mass dark matter haloes are thought to provide the majority of ionizing photons needed to reionize the Universe, due to their high...

Massive sets of stellar spectroscopic observations are rapidly becoming available and these can be used to determine the chemical composition and evolution of...

An attractive diagnostic tool for investigating the magnetism of the solar chromosphere is the observation and theoretical modeling of the Hanle and Zeeman...