Astro AGATHA

CONCERTO line intensity mapping in COSMOS

The CONCERTO (CarbON CII line in post-rEionisation and ReionisaTiOn epoch) instrument is a low-resolution spectrometer based on the lumped element kinetic inductance detectors (LEKID) technology. It has large-field-of-view and operates in the range between 130 – 310 GHz. CONCERTO’s Principal Investigator is Guilaine Lagache from the Laboratoire d’Astrophysique de Marseille (France) and the Instrument Scientist is Alessandro Monfardini from Institut Néel (France).


We are conducting a key survey of about 1.4 sq. deg. in the COSMOS field with CONCERTO. We aim to map the 3D fluctuations of the [CII] line intensity through the cosmic reionization epoch. For this, our survey will exploit a technique known as “intensity mapping” which probes cosmic structures by measuring the aggregate line emission from all galaxies across redshift. The [CII] line is a promising choice for its brightness and its role as a tracer of star-formation activity. Our survey will give the first constraints on the power spectrum of [CII]- emitting galaxies at z ≥ 5 (see Figure 3), allowing us to measure : (i) the typical halo mass scale of star-forming galaxies, (ii) the star formation rate density, (iii) the number counts of [CII]-emitters, (iv) the average ISM conditions in high- z galaxies. Our survey also measures the CO and [CI] intensity fluctuations arising from z ≤ 2.5 galaxies, yielding (v) the spatial distribution and abundance of molecular gas at cosmic noon. Cross-correlation with multi-wavelength data (e.g. LAE, LBGs) will provide (vi) additional astrophysical information, as on early metal enrichment and global history of reionization. M. Aravena is co-PI of the CONCERTO survey in COSMOS (PI: G. Lagache). This work is done in collaboration with G. Lagache (Marseille), A. Beelen (Marseille), C. De Breuck (ESO), E. Ibar (U. Valparaiso), and the CONCERTO team.