We examine the metallicity and age of a large set of Sloan Digital Sky Survey/Data Release 6 galaxies that may be blue compact dwarf (BCD) galaxies during...

Extremely metal-poor (XMP) galaxies are defined to have a gas-phase metallicity smaller than a tenth of the solar value (12+{log}[{{O/H}}]\lt 7.69). They are...

We discuss methods and preliminary results in a search for variable stars in the Carina dSph galaxy. This galaxy presents a complex star formation history and...

The bright gamma-ray quasar 4C +55.17 is a distant source (z = 0.896) with a hard spectrum at GeV energies as observed by the Large Area Telescope (LAT) on...

The presence of double-peaked/multi-component emission-line profiles in the spectra of galaxies is commonly identified by visual inspection. However, the...

We are carrying out a long-term project with the main purposes of finding and analyzing low metallicity galaxies. A very small number of very low metallicity...

We are carrying on several surveys in nearby galaxies aiming to find, catalogue and study old and young emission-line objects as H II regions, Planetary Nebulae...

Context. Clusters of galaxies are located at the intersection of cosmic filaments and are still accreting galaxies and groups along these preferential...

Distant clusters of galaxies provide a powerful method to study the formation and evolution of galaxies, and large scale structure of the Universe. However, the...