APEX - Call for Proposals 2025

The large research infrastructure EU-ARC.CZ, in collaboration with the Max Planck Institute for Radioastronomy, is pleased to announce the opening of a Call for observing proposals for the Atacama Pathfinder Experiment (APEX) telescope intended for the Czech research community. The deadline for proposal submission is on 30^th of April, 2025. The observations will be scheduled in the period 14-18 May 2025, with about 70 hours available for approved science observations. Please take into account that the APEX operations are restricted to observations in the night and morning shifts, hence focusing on the best weather conditions. Observations are therefore in general conducted between 20:00 and 12:00 local time and the corresponding visibilities of targets should be considered.

The key dates of the Call for Proposals:

Date	Milestone
30 April	Proposal submission deadline
7 May	Announcement of the outcomes of the proposal review process
14-18 May	Observations Run at the APEX telescope

APEX is a 12m submillimeter telescope situated at an altitude of 5107m on Llano de Chajnantor in Chile. For details on the facility and its operation please look at www.apex-telescope.org. The following APEX instruments will be available in the Call:

nFLASH receiver will provide two frequency channels, nFLASH230 (196-281 GHz) and nFLASH460 (~378-508 GHz). Simultaneous observations with both nFLASH channels are possible with a slightly reduced performance due to losses in the dichroics.
SEPIA receiver covers with three cartridges SEPIA180 (ALMA Band 5, 159-211 GHz), SEPIA345 (ALMA Band 7, 272-376 GHz) and SEPIA660 (ALMA Band 9, ~590-725 GHz). Note that the Band 7 part of SEPIA will NOT be available this semester.
LASMA 7-pixel multibeam array operating in the 345 GHz atmospheric band providing sideband-separated data with up to 6 GHz each, tunable within 273 to 374 GHz.
N3AR 3mm receiver in the 70 to 115 GHz atmospheric window is currently in commissioning. Observations together with nFLASH230 are optional, although with increased noise in this channel. Proposals will be only accepted on a shared risk basis and provided that science commissioning will be finished this semester.

Proposals should be prepared using this template as a single pdf file and submitted via email to apex@asu.cas.cz with “APEX proposal 2025” in the subject. The accepted observations will be done on the best effort basis.

To answer questions, and for further information and help, please contact EU-ARC.CZ at apex@asu.cas.cz.