We have used the tuneable filter system of OSIRIS to observe the [SII] doublet lines at λλ617.7 and 673.1 nm in emission across the full face of NGC 6946, and estimated the in situ electron densities for 387 HII regions, so far. The values decline steadily from over 350 cm^-3 at 1/3 R_{25} to around 175 cm^-3 at 2/3 R_{25}.

Context. The unified model of active galactic nuclei (AGN) claims that the properties of AGN depend on the viewing angle of the observer with respect to a toroidal distribution of dust surrounding the nucleus. Both the mid-infrared (MIR) attenuation and continuum luminosity are expected to be related to dust associated with the torus. Therefore

Numerical simulations of double-barred galaxies predict the build-up of different structural components (e.g. bulges, inner discs) in the central regions of disc galaxies. In those simulations, inner bars have a prominent role in the internal secular evolution of their host galaxies. The development of bulges and inner discs is, however, poorly

Una de las cuestiones básicas de la Astronomía moderna es cómo las galaxias de las diferentes familias han evolucionado desde su formación. Una de estas familias, las galaxias de tipos tempranos (ETGs, del inglés Early-Type Galaxy), formadas por galaxias elípticas y lenticulares y que contienen la mayor parte de la materia luminosa del Universo, ha

Ultra Luminous X-ray Sources (ULXs) are extragalactic X-ray point sources with L_X ˜ 10^39-10^41 erg s^-1 discovered in the 80s with the Einstein satellite and confirmed as black hole X-ray binaries during the last decade. The nature of the compact object is highly controversial. They could be super-Eddington stellar-mass black holes or

The use of deep blank fields is crucial for the correct operation of the GTC. Hitherto, the list of deepest blank fields was the compilation by M. Azzaro for the ING telescope. However, they demonstrated to be shallow for large class telescopes. We used TESELA, a new VO tool, to determine blank fields for their use with OSIRIS at the GTC. The