CONCERTO

CONCERTO (loosely for Carbon CII Line in Post-Reionization and Reionization Epoch) is a spectrometer for intensity mapping of the redshifted ionized carbon forbidden line [CII] from the epoch of reionization and from subsequent star formation. The spectral line is in the submillimeter range, and the instrument will disperse wavelengths with a Martin-Puplett interferometer (type of adjustable Michelson interferometer) and sense with KIDs, achieving spectral resolutions down to 1 GHz and angular resolutions down to 20 arcseconds. In addition to its intended intensity mapping, the instrument was used to study galaxy clusters. The instrument was installed in 2020-2021 on the Atacama Pathfinder Experiment (APEX), data was collected during 2021-2022, and the instrument was removed in 2023. As of 2/2025, I presume data analysis might be continuing.

A related effort is KISS (for KIDs Interferometer Spectrum Survey) with an analogous instrument for a lower frequency range, aiming to map Sunyaev-Zel'dovich effects. It is installed on one of the two 2.25-m QUIJOTE telescopes at Teide Observatory on the Canary Islands.