We explore the possibility of discriminating dark energy models from the study of the growth of matter perturbations. For the sake of simplicity, instead of dealing with a great number of models, we have chosen a simple model of dark energy (px=ω0ρxγ, with ω0 0; px, and ρx being pressure and energy density), which is able to reproduce a great

In February 2004 the Cute-SCIDAR instrument was installed at the 1m Jacobus Kapteyn telescope (JKT) for a systematic monitoring of the atmospheric turbulence at the Observatorio del Roque de los Muchachos (ORM). The proper knowledge of the atmospheric turbulence structure is crucial for optimising the efficiency of adaptive optics systems. SCIDAR

We present Cu and Zn abundances for 38 FGK stars, mostly dwarfs, spanning a metallicity range between solar and [Fe/H] = -3. The abundances were obtained using Kurucz's local thermal equilibrium (LTE) model atmospheres and the near-UV lines of Cu I 3273.95 Å and Zn I 3302.58 Å observed at high spectral resolution. The trend of [Cu/Fe] versus [Fe/H]

We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other cosmic microwave background (CMB) data and external priors. Within the flat Λ cold dark matter (ΛCDM) model, we find that the inclusion of high-resolution data from the VSA modifies the limits

We present an investigation of the structure of the emission line region in a sample of 12 single-peaked Active Galactic Nuclei (AGNs). Using the high resolution Hβ and Hα line profiles observed with the Isaac Newton Telescope (La Palma) we study the substructure in the lines (such as shoulders or bumps) which can indicate a disk or disk-like

This paper presents high-resolution (0.6") spectropolarimetric observations of very quiet solar regions. We make determinations of the magnetic flux density, intrinsic field strength, and magnetic filling factor in these regions. Our results confirm other previous works in that most of the internetwork flux is in the form of intrinsically strong