Accretion onto compact objects, such as black holes and neutron stars, is one of the most powerful processes in the Universe, involving large exchanges of mass and energy. Among the astrophysical systems where this phenomenon is observed, X-ray binaries are particularly relevant due to their relatively short timescales of evolution, which are

Desde el descubrimiento de que existen diferentes tipos de galaxias nos hemos preguntado sobre su formación y evolución. ¿Evolucionan de manera diferente las galaxias de distintos tamaños y masas? Las galaxias gigantes y masivas fueron las primeras en ser estudiadas, su alta luminosidad superficial permitió que los primeros telescopios las

This thesis focuses on the study of atmospheres of main sequence cool stars (spectral types G2V, K0V, and M2V, with solar metallicity) by means of three-dimensional time-dependent magneto-hydrodynamic simulations of their near-surface convection and photospheres. The simulations are computed with the MANCHA code, which is adapted to simulate other