A $\gamma$-ray determination of the Universe's star-formation history
Abstract
The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for rays via photon-photon interactions, leaving an imprint in the spectra of distant -ray sources. We measure this attenuation using {739} active galaxies and one gamma-ray burst detected by the {\it Fermi} Large Area Telescope. This allows us to reconstruct the evolution of the EBL and determine the star-formation history of the Universe over 90\% of cosmic time. Our star-formation history is consistent with independent measurements from galaxy surveys, peaking at redshift . Upper limits of the EBL at the epoch of re-ionization suggest a turnover in the abundance of faint galaxies at .
Keywords
Cite
@article{arxiv.1812.01031,
title = {A $\gamma$-ray determination of the Universe's star-formation history},
author = {LAT Collaboration and M. Ajello and K. Helgason and V. Paliya and J. Finke and A. Dominguez and A. Desai},
journal= {arXiv preprint arXiv:1812.01031},
year = {2018}
}
Comments
Published on Science. This is the authors' version of the manuscript