Context. The upcoming new generation of optical spectrographs on four-meter-class telescopes, with their huge multiplexing capabilities, excellent spectral resolution, and unprecedented wavelength coverage, will provide invaluable information for reconstructing the history of star formation in individual galaxies up to redshifts of about 0.7. Aims

We present a deep Blanco/DECam colour-magnitude diagram (CMD) for the large but very diffuse Milky Way satellite dwarf galaxy Crater II. The CMD shows only old stars with a clearly bifurcated subgiant branch (SGB) that feeds a narrow red giant branch. The horizontal branch (HB) shows many RR Lyrae and red HB stars. Comparing the CMD with [Fe/H] =

In this thesis, an extensive exploration of the low surface brightness Universe has been undertaken. A special emphasis has been placed on reducing the limitations arising from the use of integrated photometry, such as the residuals due to the observation and reduction of astronomical data, the effects of the point spread function and the presence

Context. Because of the complex physics that governs the formation of chromospheric lines, interpretation of solar chromospheric observations is difficult. The origin and characteristics of many chromospheric features are, because of this, unresolved. Aims: We focus on studying two prominent features: long fibrils and flare ribbons. To model these

We study the rest-frame optical mass-size relation of bulges and discs from z ̃ 2 to z ̃ 0 for a complete sample of massive galaxies in the CANDELS fields using two-component Sérsic models. Discs and star-forming galaxies follow similar mass-size relations. The mass-size relation of bulges is less steep than the one of quiescent galaxies (best

The traditional measurement of the size of galaxies, the effective radius, is a relic of the epoch when shallow imaging was unable to capture the full extension of astronomical sources. However, current deep imaging surveys have revolutionised our view of these objects, allowing us to regard critically our own conventions. In this sense, it is time