Signatures of early structure formation at FIR/sub-mm wavelengths

DE ROSSI, MARÍA EMILIA; BROMM, VOLKER

Workshop; DARK SIDE OF THE UNIVERSE; 2019

Luminous sources at high redshifts, such as the first galaxies, constitute promising targets for next-generation surveys, providing unique avenues to test models of early structure formation. We explore the possibility of detecting FIR/sub-mm signatures of the first galaxies by implementing select models of primordial dust emission. According to our findings, primeval galaxies would contribute to the observed cosmic background at FIR/sub-mm bands, although their imprint is hidden in dominant foregrounds. Our results also suggest that systems of a given virial mass would exhibit larger dust luminosities at higher redshifts (z>7), as a consequence of the increase in dust temperature, driven by the higher temperature floor set by the CMB. In addition, high-z systems are more concentrated, which enhances the heating efficiency associated with stellar radiation. Although predicted fluxes from typical galaxies at z~10 are below the capabilities of current observatories, they will become a target for next-generation telescopes. Leveraging the strong dependence of the predicted FIR/sub-mm emission on the nature of primordial dust, future FIR/sub-mm campaigns will play a crucial role in exploring the properties of the ISM and star formation in the early universe.