An observational determination of the evolving extragalactic background
  light from the multiwavelength HST/CANDELS survey in the Fermi and CTA era
  The diffuse extragalactic background light (EBL) is formed by ultraviolet
(UV), optical, and infrared (IR) photons mainly produced by star formation
processes over the history of the Universe, and contains essential information
about galaxy evolution and cosmology. Here, we present a new determination of
the evolving EBL spectral energy distribution using a novel approach purely
based on galaxy data aiming to reduce current uncertainties on the higher
redshifts and IR intensities. Our calculations use multiwavelength observations
from the UV to the far-IR of a sample of approximately 150,000 galaxies
detected up to $z\sim 6$ in the five fields of the Cosmic Assembly
Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) from the Hubble Space
Telescope. This is one of the most comprehensive and deepest multi-wavelength
galaxy datasets ever obtained. These unprecedented resources allow us to derive
the overall EBL evolution up to $z\sim 6$ and its uncertainties. Our results
agree with cosmic observables estimated from galaxy surveys and $\gamma$-ray
attenuation such as monochromatic luminosity densities, including those in the
far-IR, and star formation rate densities, also at the highest redshits.
Optical depths from our EBL approximation, which will be robust at high
redshifts and for $\gamma$ rays up to tens of TeV, will be reported in a
companion paper.
