APEX - Atacama Pathfinder Experiment

APEX, the Atacama Pathfinder Experiment, is a 12 m diameter submillimetre telescope at 5100 m altitude in the Atacama Desert in northern Chile.

APEX was inaugurated in September 2005, and provides almost unique opportunities for astronomers to use submillimetre observations to study the first galaxies and how stars and planets are formed.

The APEX project (Güsten et al. 2006, Astronomy & Astrophysics, vol. 454, L3) is a collaboration between Onsala Space Observatory, Max Planck Institut für Radioastronomie (Germany), and the European Southern Observatory 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 Germany.

Onsala Space Observatory, through the Group for Advanced Receiver Development (GARD), provides facility heterodyne receivers (Swedish Heterodyne Facility Instrument, SHFI) for several frequency bands up to 1.3 THz (Belitsky et al. 2006, Proceedings of SPIE Vol. 6275, 62750G; for astronomy related information see Vassilev et al. 2008, Astronomy & Astrophysics, vol. 490, 1157). SHFI was decommissioned in 2017. 

The receiver SEPIA (Swedish ESO PI receiver for Apex) was installed in 2015. It includes an ALMA Band 5 (159-211 GHz) channel (see Billade et al. 2012, IEEE Trans. Terahertz Science and Technology, Vol. 2, No. 2, March 2012, pp.208-214), ​an ALMA Band 7 (272-376 GHz) channel, and an ALMA Band 9 (600-722 GHz) channel.

The entire Astronomy & Astrophysics issue 454 No 2 (August 2006) was an APEX special booklet.

In scientific publications containing APEX data please acknowledge the project with the following footnote: "Based on observations with the Atacama Pathfinder EXperiment (APEX) telescope. APEX is a collaboration between the Max Planck Institute for Radio Astronomy, the European Southern Observatory, and the Onsala Space Observatory.", and give the project ID for the observations. Please also make references to publications about the telescope and receiver(s); see above for SHFI and SEPIA, or see the APEX web site.

The links above to publications are to Chalmers Publication Library, where more information about the publications can be found (incl. BibTeX entries and the full text).

Contact person

Per Bergman
Email: per.bergman@chalmers.se, Phone: +46 31 772 5569


APEX web site
> http://www.apex-telescope.org/

Proposals for observations on Swedish time on APEX
Calls for proposals are normally issued twice per year, with deadlines in April/May and October (see link below for detailed information). Swedish time on APEX is open for scientists from all countries.
> http://www.chalmers.se/en/centres/oso/radio-astronomy/proposals/Pages/default.aspx

Observed projects
Observed projects on Swedish APEX time
> http://www.chalmers.se/en/centres/oso/radio-astronomy/apex/Pages/Observed-projects.aspx

ESO Science Archive Facility
> http://archive.eso.org/cms.html

ESO Science Archive APEX Query Form
> http://archive.eso.org/wdb/wdb/eso/apex/form

Published: Tue 03 Sep 2013. Modified: Tue 19 Dec 2017