The Project

The A2C2S will measure the C+ and far-infrared (FIR) continuum emission for a representative sample of 118 main sequence star-forming galaxies spectroscopically confirmed at 4~10 M_Sun/yr and stellar mass ~9 < log(Mstar) < ~11. The proposed A2C2S data are crucial to understanding the gas and dust properties at a time of rapid galaxy maturation.

At the key epoch 4 < z < 6, the A2C2S will provide :
- The first comprehensive and precise (<20%) measurement of the star formation rate density (SFRD) at these epochs from UV+FIR continuum and C+ emission, allowing to constrain mechanisms which fuel the initial growth of typical galaxies in the early universe.
- A first detailed characterization of the ISM properties using LFIR/LUV and C+/FIR diagnostics.
- A first measurement of dynamical masses from spectrally resolved C+, combined with stellar masses and statistical estimates of dark matter halo masses to measure dust content, gas fraction, and their evolution.

Beyond these immediate results, the A2C2S will provide a lasting legacy in data-rich ECDFS and COSMOS areas. These data will pave the way for detailed follow-up observations, e.g., with ALMA at higher spatial resolution, and provide a reference sample for studies with future facilities like JWST.