Protocluster of Galaxies Undergoing Rapid Growth

The epoch from 9 to 11 billion years ago represents a time when adolescent galaxies were growing vigorously, and is thus an important era for the study of galaxy formation. The Subaru Telescope discovered a protocluster of galaxies during this epoch of rapid galaxy growth. Based on the observation of H-alpha emission lines coming from the star-forming region, scientists found the very intense star formation rates, sometimes reaching over 100 times greater than that of the Milky Way Galaxy. The protocluster in this era will serve as an ideal laboratory for investigating how a cluster develops and how a special, dense environment can influence the formation and evolution of galaxies.