Welcome to the home page of the Bouwens research group at Leiden University!

What is the life history of galaxies?    At which time in the universe do galaxies form and build up and which physical processes shape the observed properties of individual galaxies like our own, the Milky Way?

Our research team studies the growth and evolution of galaxies from the earliest epochs in cosmic time from an observational stand point.   This involves all properties of galaxies that are amenable to study from current telescopes, from their luminosities or brightnesses, their sizes or morphologies, as well as derived physical properties for galaxies, including their star birth rates, their mass in stars and in dark matter, and their kinematic properties.    Our quest to understand the growth of galaxies from the earliest times is all the more tantalizing, due to its occurring during the same time period as the reionization of hydrogen in the universe (in the first 1 billion years).    Our tools to study galaxies at such times are many: the Hubble Space Telescope, the Spitzer Space Telescope, large ground-based telescopes like Keck and VLT, the Atacama Large Millimeter Array, and in the future the James Webb Space Telescope.