The Atacama Pathfinder Experiment (APEX) in 2023 and future opportunities

The Atacama Pathfinder Experiment (APEX)  12m submillimeter telescope has significantly contributed to a wide variety of astronomy science areas, ranging from the discoveries of new molecules to large-scale and deep imaging of the submillimeter sky. APEX has been operated since 2005, initially by a partnership between the Max Planck Institute for Radio Astronomy (MPIfR), the European Southern Observatory (ESO) and the Onsala Space Observatory (OSO). This partnership ended in 2022 and now APEX is a sole project of the MPIfR, hosted and operated by ESO.

Throughout these years, 10% of the APEX observing time has been allocated to the Chilean astronomical community, among others to prepare and complement science with ALMA. Chilean scientists have conducted state-of-the-art submm research and also participated as important partners in large APEX projects.

In recent years, APEX has been significantly improved with upgrades to the antenna itself as well as new heterodyne instruments highly complementary to ALMA. A new large-format, dual frequency continuum camera operating at 350 and 870 μm simultaneously and a new high frequency heterodyne receiver covering the 350 μm atmospheric window are scheduled for installation this year. With operations currently secured until the end of 2025, the MPIfR is now looking at future operation options from 2026 onwards.

This workshop aims at presenting the APEX 2023 status to the Chilean mm/submm astronomical community and to start a dialog about future mm/submm single dish science interests in Chile and a possible stronger future involvement in the APEX project.

The workshop will cover the main aspects of the observatory from logistics and  instrumentation to ongoing  scientific programs and future science opportunities with APEX (see introductory talks). We  specifically invite contributions from the Chilean community on any of these topics and future interests related to mm/submm astronomy, including new developments on instrumentation and synergies with current and future observatories in Chile.  The workshop will close with a general discussion about opportunities for Chile in APEX from 2026 on.

The workshop will take place August 3-4, 2023, at Pontificia Universidad Católica de Chile.