Aims: We present here two H II region catalogues with azimuthal resolution for the two grand design galaxies NGC 628 and NGC 6946. With the help of these catalogues, we study several properties of the star-forming processes occurring in spiral galaxies. Methods: We obtained direct imaging in the narrow-band filters centred at Hα, Hβ, [O II]λ3727

We investigate the effects of interactions between ions and neutrals on the chromosphere and overlying corona using 2.5D radiative MHD simulations with the Bifrost code. We have extended the code capabilities implementing ion–neutral interaction effects using the generalized Ohm’s law, i.e., we include the Hall term and the ambipolar diffusion

Context. Spectropolarimetry at high spatial and spectral resolution is a basic tool to characterize the magnetic properties of the solar atmosphere. Aims: We introduce the KIS/IAA Visible Imaging Polarimeter (VIP), a new post-focus instrument that upgrades the TESOS spectrometer at the German Vacuum Tower Telescope (VTT) into a full vector

A brief description of the HEXAFLEX system is presented, which has been contrived to carry out two-dimensional spectroscopy (spectral imaging) in combination with the FLEX spectrograph at the 4.2 m William Herschel Telescope. Some astronomical illustrative examples are shown.

We have performed two-dimensional spectroscopy of the Seyfert galaxies NGC 5728 and 4151 in the 4500-7500A spectral range. The data (especially the [OIII] lambdalambda4959, 5007 lines), obtained using a new optical fibre system, complement previous observational work carried out by means of this technique. The two gaseous components found in NGC

Data on linear optical polarimetry were obtained during two observing runs at the Complejo Astronomico El Leoncito (CASLEO) in San Juan, Argentina, in 2003 (April 29 to May 5 and August 29 to September 2). (1 data file).