Periodic Reporting for period 1 - CONCERTO (Intensity mapping of the atomic carbon CII line: the promise of a new observational probe of dusty star-formation in post-reionization and reionization epoch)
Reporting period: 2019-01-01 to 2020-06-30
We are building, testing and will finally install the instrument on the APEX antenna, following an agreement with APEX partners. The spectrometer is based on state-of-the-art development of new arrays in the millimeter using kinetic inductance detectors. Spectra are obtained using a fast Martin-Puplett interferometer. Then, we will observe a few square degrees with CONCERTO and offer straightforward alternative for probing star formation and dust build-up in the early Universe. Finally, CONCERTO will set to music the various cosmic evolution probes. Cross-correlation of the signals will be used in particular to capture the topology of the end of reionisation era. Our novel technology targets an unexplored observable touching on some fundamental processes building the early Universe. In the flourishing of new ideas in the intensity mapping field, CONCERTO lies at the forefront.
Building such a complex instrument in a very short time is a great challenge. As of today, the mounting of the instrument is well advanced with the complete electronics, interferometer mechanics, cryostat, KIDS camera (4,300 pixels), and optical box already assembled (see the figure). The polarisers are fabricated. First tests on the camera give sensitivity in line with expectation. We presented our current results on the instrument, together with scientific forecast on the [CII] survey, in “A wide field-of-view low-resolution spectrometer at APEX: Instrument design and scientific forecast”, in the Astronomy & Astrophysics journal. We successfully passed the APEX reviews (from the preliminary design up to the final acceptance) and started the installation at APEX by mounting all the pipes in the cabin of the telescope in February 2020. We participated to the ESO call for proposal and were successfully granted 600 hours of observing time by ESO on APEX to conduct our [CII] survey. In parallel, we are developing the pipeline for data reduction that we are testing on data coming from our pathfinder instrument for CONCERTO, named KISS, and have obtained the first spectrum with KISS. We have built new realistic simulations of the extragalactic sky that include both dust continuum and [CII] and CO spectral features (see the figure). These simulations are unique and will serve as a reference for (sub)-millimeter intensity mapping experiments.