Where stars are born : Kinematics and photometry of starburst and postburst galaxies

Abstract: The understanding of the formation and evolution of galaxies will not be complete until we understand the physical processes that trigger and regulate starformation in them. This work is about star formation on several size scales. It includes the kinematic study of 157 H II regions in the spiral galaxy M83, in order to test the relation, if any, between luminosity (L) and velocity dispersion(s), indicative of virialization. We found that there is no strong correlation between the mentioned variables, but only an upper envelope with a maximum luminosity for a given velocity dispersion. We demonstrated that this envelope has a slope that is strongly dependent on an accurate correction of instrumental broadening. Using our experience in H II regions, we moved to star formation at larger scales. Thus, the bulk of this thesis is on starburst galaxies and their evolutionary descendants, the postburst galaxies. A starburst is a galaxy that is suddenly creating large amounts of stars, at a rate that is not sustainable for long periods.We performed a kinematic study of a sample of 11 such objects, showing that they are, in general, not supported by rotation and that many of them are consistent with a recent merger which affected their morphology and kinematics.Furthermore, from Sloan Digital Sky Survey (SDSS) we extracted a robust sample of 1006 starbursts and 240 postbursts at redshift 0.010<z<0.083. We performed a comparative study of their structural parameters, such as effective radius, sersic index, asymmetry and absolute magnitude. We have found that the majority of starbursts and postbursts in the nearby Universe are disky galaxies, with a tendency for starbursts to have shorter effective radii and larger asymmetries.