Attempting to measure the evolution of the universe requires a huge sample of objects. Observations of millions of galaxies, looking further and further back in time, are needed to make an enormous 3D map of the universe. This type of galactic surveying is being carried out by several groups worldwide, and now the Very Large Telescope (VLT) is set to make a major contribution to this, the biggest map in the universe.
One of the instruments to be installed this year at the VLT is a multi-object spectrograph called VIMOS that can obtain spectra of up to 6400 individual objects in a single exposure. This is two or three times more efficient than existing counterparts.
In the future, the VLT will also be equipped with NIRMOS, the infrared equivalent to VIMOS, which will detect emission from galaxies whose optical emission is obscured by intervening dust. Together, VIMOS and NIRMOS will allow astronomers to map a time interval spanning more than 90% of the age of the universe.