A gamma-ray determination of the Universe's star formation history

Abdollahi, S.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Buson, S.; Bregeon, J.; Bruel, P.; Buehler, R.; Cameron, R. A.; Caputo, R.; Caraveo, P. A.; Cavazzuti, E.; Charles, E.; Chen, S.; Cheung, C. C.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Costantin, D.; Cutini, S.; D'Ammando, F.; De Palma, F.; Desai, A.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Domínguez, A.; Favuzzi, C.; Fegan, S. J.; Finke, J.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gallardo Romero, G.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Green, D.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hartmann, D. H.; Hays, E.; Helgason, K.; Horan, D.; Jóhannesson, G.; Kocevski, D.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Magill, J. D.; Maldera, S.; Manfreda, A.; Marcotulli, L.; Mazziotta, M. N.; Mcenery, J. E.; Meyer, M.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ojha, R.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Palatiello, M.; Paliya, V. S.; Paneque, D.; Perkins, J. S.; Persic, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Porter, T. A.; Primack, J. R.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, M.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Torresi, E.; Tosti, G.; Tramacere, A.; Troja, E.; Valverde, J.; Vianello, G.; Vogel, M.; Wood, K.; Zaharijas, G.

doi:10.1126/science.aat8123

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 gamma rays via photon-photon interactions, leaving an imprint in the spectra of distant gamma-ray sources. We measured this attenuation using 739 active galaxies and one gamma-ray burst detected by the Fermi Large Area Telescope. This allowed 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 z ~ 2. Upper limits of the EBL at the epoch of reionization suggest a turnover in the abundance of faint galaxies at z ~ 6.

A gamma-ray determination of the Universe's star formation history / Abdollahi, S., Ackermann, M., Ajello, M., Atwood, W.B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Blandford, R.D., Bloom, E.D., Bonino, R., Bottacini, E., Buson, S., Bregeon, J., Bruel, P., Buehler, R., Cameron, R.A., et al.. - In: SCIENCE. - ISSN 0036-8075. - 362:6418(2018), pp. 1031-1034. [10.1126/science.aat8123]