Cosmic dust absorbs the optical/UV photons produced by stars and SMBH and re-emits the energy at longer wavelengths in the IR regime. Infrared observations are, therefore, crucial to achieving a complete picture of the star-formation density (SFRD) , and to understanding the properties of dust across cosmic time. Thanks to the latest IR Herschel satellite (2009-2013), a comprehension of the SFRD was estimated up to z~3-4, but recent observations in the sub-mm regime (SCUBA-2) show discrerpancies with previous Herschel results. I will discuss the possible reasons for this discrepancy and show the critical role that the IR SPICA will play in the future .
Local contact, organization: M. Galametz