APEX is designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range — between infrared light and radio waves — and to find targets that ALMA will be able to study in greater detail.

Submillimetre astronomy provides a window into the cold, dusty and distant Universe, but the faint signals from space are heavily absorbed by water vapour in the Earth's atmosphere.

[1] APEX was a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR) (55%), the Onsala Space Observatory (OSO, 13%), and the European Organisation for Astronomical Research in the Southern Hemisphere ESO (32%).

Astronomers use this light to study the chemical and physical conditions in these molecular clouds — the dense regions of gas and cosmic dust where new stars are being born.

[1] Its first results proved the telescope lives up to the ambitions of the scientists by providing access to the "cold Universe" with unprecedented sensitivity and image quality.

No fewer than 26 articles based on early science with APEX were published in July 2006 in a special issue of the research journal Astronomy and Astrophysics.

LABOCA's high sensitivity, together with its wide field of view (11 arcminutes, one third of the diameter of the full Moon), make it an invaluable tool for imaging the submillimetre Universe.