Molecular lines are generally very good tracers of the physical conditions in cold regions of the Universe (e.g. molecular clouds, cool stars, etc.), but molecular species are also found in not so cold environments (e.g. the magnetized solar atmosphere). For a reliable interpretation of spectroscopic and spectropolarimetric observations of

We present spectropolarimetric observations of internetwork magnetic fields at the solar disk center. A Fabry-Pérot spectrometer was used to scan the two Fe I lines at 6301.5 and 6302.5 Å. High spatial resolution (0.5") magnetograms were obtained after speckle reconstruction. The patches with magnetic fields above noise cover approximately 45% of

Line profiles in ensuremath {{H}alpha } emission from H II region populations in spiral galaxies show emission features at +/-50 km/s from the main emission peaks of a significant fraction of regions, which are characteristic of expanding shells. We interpret these in two possible scenarios: mass-loaded wind outflows from the central OB stars, or

Photometric and spectroscopic parameters for 191 galaxies in the UCM Survey of emission-line galaxies Lists I and II (Cats. and ). For each galaxy, the table gives: redshift, BrJKs magnitudes and errors inside 3 disk-scale circular apertures (measured in r), Hα equivalent widths and errors, aperture sizes in kpc, Hα/Hβ ratio (corrected for stellar

Shakhbazian compact galaxy groups are the most dense configurations known. A few years ago we commenced a detailed spectral and photometric study of these groups. In this paper we present the investigation results of groups ShCG1, ShCG8, ShCG3, and ShCG82. The redshifts of member galaxies, the results of the BVR photometry, the surface-brightness

Sampling fluctuations in stellar populations give rise to dispersion in observables when a small number of sources contribute effectively to the observables. This is the case for a variety of linear functions of the spectral energy distribution (SED) in small stellar systems, such as galactic and extragalactic HII regions, dwarf galaxies or stellar