Center-to-limb investigations of solar photospheric magnetic features at high spatial resolution

When observed from the disk center to the limb, small-scale magnetic features in the photosphere exhibit an increase in brightness contrast (i. e. relative to quiet surroundings) along with a change in appearance from Bright Points (BPs) to faculae. The work presented in this dissertation has been dedicated to the investigation of the center-to-limb variation (CLV) of both the appearance and brightness of these small-scale magnetic features, based on images and spectro-polarimetric data at a very high spatial resolution. The goals were to provide novel observational constraints for MHD models and a deeper understanding of the relationhip between the features appearing as Bright Points (BPs) and faculae. To study the variation of appearance, a photometric method based on Linear Discriminant Analysis was developed to classify BPs and faculae at various heliocentric angles. This allowed the determination of a CLV of the relative number of BPs and faculae as well as the statistical analysis of their brightness and morphology. Spectro-polarimetric scans at a constant spatial resolution (Hinode satellite) were then used to assess the dependence of the continuum contrast of magnetic features on both the heliocentric distance and on magnetic parameters inferred by inversions.