HETDEX - looking into the nursery of the Universe
The large scale distribution of galaxies in the universe is not random. There exists a typical scale, i.e. a characteristic mean distance between the galaxies, which can be used to study the expansion of the universe over time. Experiments such as the Sloan Digital Sky Survey already exploit this fact very successfully. Until now, however, it was only possible to study galaxies in a certain range of distances.
HETDEX at the 9.2m telescope of the McDonald Observatory in Texas will search for so-called Lyman-Alpha emitting galaxies. These emit a large fraction of their light at a certain wavelength and thus make it possible to observe them over vast distances. With these galaxies, HETDEX can study the expansion of the Universe at a time, when it had only a quarter of its present size. Dr. Maximilian Fabricius from the Max Planck Institute for Extraterrestrial Physics will explain the aims and the preparations of this experiment during the next Cafe&Kosmos.
last update 2011-09-08 by H. Steinle