eso9915 — Science Release
VLT Studies Very Distant Galaxies
27 February 1999: Continuing progress in astronomical technology is opening new possibilities for the study of the distant universe. One of the most exciting, recent additions to this branch of astrophysics, known as cosmology, has been the discovery of a large population of galaxies in the primordial Universe in which intensive star-formation is going on. They are so distant (their redshifts are larger than 3 ) that the corresponding look-back time is over 90% of the age of the Universe, now estimated at about 14 - 15 billion years (1 billion = 1,000 million). We observe these objects as they were, when the Universe was between 1 and 2 billion years old. The investigation of the early Universe is one of the primary scientific goals that have motivated the construction of the ESO Very Large Telescope and its very diverse complement of instrumentation. The aim of these studies is to extend the observations of basic properties of galaxies to objects at the largest possible distances and hence the earliest possible epochs. We would like to learn as much as possible about these very faint galaxies, including their numbers and hence their space density, as well as their brightness, colours, sizes and shapes. What are the rates with which stars are formed in different galaxies at different epochs, what is their chemical composition and mass? How do they move in space and how do they cluster?