Rotation plays a key role in the life cycles of stars with masses above 8 Msun. Hence, accurate knowledge of the rotation rates of such massive stars is critical for understanding their properties and for constraining models of their evolution.This paper investigates the reliability of current methods used to derive projected rotation speeds v sin i from line-broadening signatures in the photospheric spectra of massive stars, focusing on stars that are not rapidly rotating.We use slowly rotating magnetic O-stars with well-determined rotation periods to test the Fourier transform (FT) and

Supernova remnants are among the most spectacular examples of astrophysical pistons in our cosmic neighborhood. The gas expelled by the supernova explosion is launched with velocities ∼1000 km/s into the ambient, tenuous interstellar medium, producing shocks that excite hydrogen lines. We have used an optical integral-field spectrograph to obtain high-resolution spatial-spectral maps that allow us to study in detail the shocks in the northwestern rim of supernova 1006. The two-component Halpha line is detected at 133 sky locations. Variations in the broad line widths and the broad-to-narrow

The number of present-day massive galaxies that has survived untouched since their formation at high-z is an important observational constraint to the hierarchical galaxy formation models. Using three different semianalytical models based on the Millenium simulation, we quantify the expected fraction and number densities of the massive galaxies form at z>2 which have evolved in stellar mass less than 10% and 30%. We find that only a small fraction of the massive galaxies already form at z~2 have remained almost unaltered since their formation (<2% with Delta_M*/M*<0.1 and <8% with Delta_M*/M

Recent observations with the GTC take us a step closer to conditions in the early Universe

The project, carried out with the OSIRIS camera of the Gran Telescopio CANARIAS, has undertaken the deepest and most detailed census of the massive supercluster Cygnus OB2, one of the largest and nearest known 'nurseries' of stars

The new connection for the RedIRIS-NOVA and the Canarian R+D+i network is now established