The life-cycle of nearby galaxies: secular and external processes regulating the atomic gas content

This thesis investigates how the processes of galaxy evolution combine to regulate gas content and drive the life cycle of nearby galaxies. We use a sample of 30,000 galaxies that is representative of gas content, star formation and environment in the local Universe and take advantage of the HI spectral stacking technique. Our findings demonstrate the importance of fast-acting gas stripping due to environment and gas supply fluctuations in regulating the star formation cycle. This thesis provides new insights into the relationships between galaxy properties and environment in the local Universe, providing strong constraints for galaxy formation and evolution models.