Constraining the star formation history withFermi-LAT observations of the gamma-ray opacity of the universe
2019 July 29
The star formation history (SFH) of the Universe is of fundamental importance to cosmology, not only to galactic formation itself but also for ongoing efforts to determine cosmological parameters and matter content of the Universe . Measurements of the extragalactic background light (EBL) as a function of redshift can constrain models of the SFH, including the initial mass function(IMF) and dust extinction . The gamma-ray spectra of AGN allow us to study the extragalactic background light (EBL) through $\gamma-\gamma$ absorption of high-energy photons. In this work, we will produce constraints on models of SFH using a sample of AGN observed by the Fermi-LAT instrument by investigating the imprint of the EBL on the observed spectra of high-redshift Fermi-LAT AGN above $\sim $ 10 GeV.