In its current agreement, valid until the end of 2022, APEX is a collaboration among the Max-Planck-Institut für Radioastronomie (MPIfR) at 55%, the Onsala Space Observatory (OSO) at 13%, and the European Southern Observatory (ESO) at 32% to operate a modified ALMA prototype antenna as a single dish, on the high altitude site of Llano de Chajnantor. The telescope was manufactured by VERTEX Antennentechnik in Duisburg, Germany.
Chile is the host country of the project, and the agreement establishes that
Chilean research institutions have access to 10% of the available observing time.
The Max-Planck-Institut für Radioastronomie is part of the Max-Planck-Gesellschaft and is located in Bonn, Germany.
The MPIfR millimeter and submillimeter astronomy department investigates
a broad variety of astrophysical topics, from molecular clouds in the Milky Way and other galaxies to galaxy evolution at high redshift. The division for sub-millimeter technologies develops state-of-the-art
instrumentation for APEX and SOFIA.
The European Southern Observatory (ESO) is an intergovernmental science and technology organisation in astronomy. The ESO Headquarters are located in Garching, near Munich, Germany.
ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy, in order to enable important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research.
The Onsala Space Observatory (OSO) is the Swedish National Infrastructure for Radio Astronomy and provides scientists with equipment to study the Earth and the rest of the Universe. It is hosted by the Department of Space, Earth and Environment at Chalmers University of Technology, and is operated on behalf of the Swedish Research Council.
The Onsala Space Observatory, through the Group for Advanced Receiver Development (GARD), provides heterodyne receivers for APEX.