APEX, the Atacama Pathfinder Experiment, is a collaboration between Max Planck Institut für Radioastronomie (MPIfR) at 50%, Onsala Space Observatory (OSO) at 23%, and the European Southern Observatory (ESO) at 27% to construct and operate a modified ALMA prototype antenna as a single dish on the high altitude site of Llano Chajnantor. The telescope was supplied by VERTEX Antennentechnik in Duisburg, Germany.

Observing with APEX will allow us to study warm and cold dust in starforming regions both in our own Milky Way and in distant galaxies in the young universe. High frequency spectral lines enable the exploration of the structure and chemistry of planetary atmospheres, dying stars, molecular clouds as well as inner regions of starburst galaxies. We will address issues from the vast scales of the structure of the Universe down to the physics and chemistry of comets.

---