= Alessandro De Angelis
{c}
{tag=Physicist}
= A. De Angelis
{c}
{synonym}
<Alessandro De Angelis> coauthored calculations of the transparency of intergalactic space to <gamma rays>. The work connects an assumed background photon population with energy-dependent <optical depth> and the attenuation of distant sources.<Transparency of the Universe to gamma rays by Alessandro De Angelis and others>[Abstract: background radiation, optical depth and source distance]{ref}
High-energy photon propagation is affected by interactions with background radiation, including <pair production>. Interpreting a source's observed spectrum therefore requires both an emission model and a propagation model; a missing high-energy component need not originate entirely at the source.
Back to article page
