An Empirical Determination of the Intergalactic Background Light from UV to FIR Wavelengths Using FIR Deep Galaxy Surveys and the Gamma-ray Opacity of the Universe

Understand

We have previously calculated the intergalactic background light (IBL) as a function of redshift in the far ultraviolet to near infrared range, based purely on data from deep galaxy surveys.

• Here we utilize similar methods to determine the mid- and far infrared IBL out to a wavelength of 850 microns.
• Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors.
• By also including the effect of the 2.7 K cosmic background photons, we determine 68% confidence upper and lower limits on the opacity of the universe to gamma-rays up to PeV energies.