The Wide Field Imager

The third image of the GigaGalaxy Zoom project was taken with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the ESO La Silla Observatory. In order to optimise telescope time, the images were obtained by ESO staff astronomers, who select the most favourable observations to be made at any given time, taking into account the visibility of the objects and the sky conditions.

The La Silla Observatory, 600 km north of Santiago de Chile at an altitude of 2400 metres, has been an ESO stronghold since the 1960s. It is located at the outskirts of the Chilean Atacama Desert, one of the driest and loneliest areas of the world. Like other observatories in this geographical area, La Silla is located far from sources of light pollution and, like the Paranal Observatory, home to the Very Large Telescope, it has one of the darkest night skies on the Earth. At La Silla, ESO operates several of the most productive 2–4-metre-class telescopes in the world.

The MPG/ESO 2.2-metre Telescope has been in operation at La Silla since early 1984 and is on indefinite loan to ESO from the Max Planck Institute (Max Planck Gesellschaft or MPG in German). Telescope time is shared between MPG and ESO observing programmes, while the operation and maintenance of the telescope are ESO’s responsibility.

The telescope hosts three instruments: the 67-million pixel Wide Field Imager with a field of view as large as the full Moon, which has taken many amazing images of celestial objects; GROND, the Gamma-Ray Burst Optical/Near-Infrared Detector, which chases the afterglows of the most powerful explosions in the Universe known as gamma-ray bursts; and the high-resolution spectrograph, FEROS, used to make detailed studies of stars.