### Abstract

Contributed Talk - Splinter Computational (S26)

## REGGAE: A GPU-supported code to calculate gamma-gamma opacity in astrophysical objects

Robert Brose, Iurii Sushch

Dublin City University

REGGAE (Radiation attEnuation Gamma-Gamma Absorption Estimation) is a numeric code designed to precisely and time-efficiently calculate the opacity due to anisotropic gamma-gamma absorption for various astrophysical applications. The code is optimized for effective parallel computing using both central processing units (CPUs) and graphics processing units (GPUs). Written in a modular way in Python, it provides the flexibility to be applied to various problems. At the moment, the code supports the full integration of the anisotropic gamma-gamma scattering problem as well as the more time-efficient delta-approximation solution for the distribution of the target photons. We illustrate the functionality of the code applying it to gamma-gamma absorption in very young Supernova remnants (SNRs), where the gamma-ray emission produced by the SNRs shock gets attenuated by the photons emitted by the Supernovas photosphere.