Speaker
Description
High-energy gamma rays of interstellar origin are produced by the
interaction of cosmic-ray (CR) particles with the diffuse gas and
radiation fields in the Galaxy. The main features of this emission are
well understood and are reproduced by existing CR propagation models
employing a 2D galactocentric cylindrical symmetric geometry. However,
the high-quality data from instruments like the Fermi Large Area
Telescope reveal significant deviations from the 2D model predictions on
few to tens of degree scales, indicating that the details of the
Galactic spiral structure should be included and thus require 3D spatial
modelling. In this contribution the high-energy interstellar emissions
from the Galaxy are calculated using the latest release of the GALPROP
code for the first time employing full 3D spatial models for the
CR source, interstellar gas, and interstellar radiation field (ISRF) densities.
The interstellar emission models that include arms and bulges for the CR
source and ISRF densities provide plausible physical interpretations for
features found in the residual maps from high-energy gamma-ray data analysis.
The 3D models provide a more realistic basis for interpreting the non-thermal interstellar emissions toward the inner Galaxy and about the Galactic centre.
