Giant Ly-alpha nebulae in the high redshift (z>2) Universe

Abstract

High redshift radio galaxies (z>2) are believed to be progenitors of the giant ellipticals of today. They are often associated with giant Ly-alpha nebulae (sometimes >100 kpc), which have been for more than two decades valuable sources of information about the evolutionary status of the host galaxy and its chemical enrichment and star formation histories. I present in this paper a summary of the most relevant results about the giant nebulae obtained in the last ~10 years and the implications on our understanding of the early phases of evolution of massive elliptical galaxies.