Context. Hydrodynamical (or 3D) and non-local thermodynamic equilibrium (NLTE) effects are known to affect abundance analyses. However, there are very few observational abundance tests of 3D and NLTE models. Aims: We developed a new way of testing the abundance predictions of 3D and NLTE models, taking advantage of large spectroscopic survey data

We observed two transits of the iconic gas giant HD 209458b between 380 and 780 nm, using the high-resolution ESPRESSO spectrograph. The derived planetary transmission spectrum exhibits features at all wavelengths where the parent star shows strong absorption lines, for example, Na I, Mg I, Fe I, Fe II, Ca I, V I, Hα, and K I. We interpreted these

We report the results of a pilot spectroscopic program of a region at z = 5.2 in the GOODS-N field containing an overdensity of galaxies around the well-known submillimetre galaxy (SMG) HDF850.1. We have selected candidate cluster members from the optical 25 medium-band photometric catalogue of the project SHARDS (Survey for High-z Absorption Red

Los objetos transneptunianos son pequeños cuerpos helados que orbitan más allá de la órbita de Neptuno. Estos cuerpos se encuentran entre los menos procesados de Sistema Solar, por lo que su estudio proporciona valiosa información sobre la formación del Sistema Solar y sobre su evolución. En esta tesis presentamos el estudio de la variación de la

Variable behavior on all time scales seems to be ubiquitous phenomenon in almost all classes of active galactic nuclei. This work deals with two topics. One being detection of microvariability (intra-night variability) in the sources which are obscured and were believed to be non variable - type 2 quasars. The detection of a variable behavior in

The main objective of this Ph.D. thesis is to study the evolution of starburst galaxies during the last 8 Gyrs. At high redshift (z>1) galaxies show a large variety of unusual morphologies that are rare to find in the local Universe. The main mechanisms transforming the appearance of high-redshift galaxies are related to star formation processes