Speaker
Description
The extragalactic background light (EBL), from ultra-violet to infrared, that encodes the emission from all stars, galaxies and actively accreting black holes in the observable Universe is critically important to probe models of star formation and galaxy evolution, but remains at present poorly constrained. The Large Area Telescope (LAT), on board Fermi, produced an unprecedented measurement (relying on 750 blazars and the first 9 years of Pass 8 data) of the EBL optical depth at 12 different epochs from redshift 0 up to a redshift of 3. In this talk, we will present the measurement and how it constrains the EBL energy density and its evolution with cosmic time. We will also discuss how this paves the road to the first point-source-independent determinations of the star-formation history of the Universe.
