Measuring the Extragalactic Background Light with gamma-ray telescopes

by Abelardo Moralejo Olaizola (FAE, Barcelona (E))

Thursday 30 Jun 2016, 15:00 → 16:30 Europe/Rome

1/1-2 - Aula "C. Voci" (Dipartimento di Fisica e Astronomia - Edificio Marzolo)

The Extragalactic Background Light (EBL) is the ensemble of all the light produced, mostly by stars, through the history of the Universe, and the fraction of it reprocessed by dust in galaxies. The EBL spans the IR to UV range of the electromagnetic spectrum, and is, in terms of total energy content, the second strongest background radiation field in the Universe (after the CMB). While direct measurements in this band are hampered by foreground noise from the Solar System and the Milky Way, the EBL can also be studied through its interaction (via pair production) with very high energy photons traversing cosmological distances. The gamma-ray spectra of extragalactic sources bears an imprint of its interaction with the EBL, from which the current-generation of gamma-ray observatories are obtaining very competitive constraints on the EBL density and spectrum. The talk will review the status of this field of research, with an emphasis in the results obtained with MAGIC and other ground-based gamma-ray telescopes in recent years.

slides are available at the INFN agenda of this event https://agenda.infn.it/event/18555/