A gamma-ray determination of the Universe’s star formation history
GUILLEMOT, L.
Laboratoire de Physique et Chimie de l'Environnement et de l'Espace [LPC2E]
Unité Scientifique de la Station de Nançay [USN]
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Laboratoire de Physique et Chimie de l'Environnement et de l'Espace [LPC2E]
Unité Scientifique de la Station de Nançay [USN]
Language
en
Article de revue
This item was published in
Science. 2018, vol. 362, n° 6418, p. 1031-1034
American Association for the Advancement of Science (AAAS)
English 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 $\gamma$ rays via ...Read more >
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 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 $z\sim2$. Upper limits of the EBL at the epoch of re-ionization suggest a turnover in the abundance of faint galaxies at $z\sim 6$.Read less <
Origin
Hal imported