  Reliable identification of the origin of the high-energy non-thermal emission
from the Galactic Center (GC) is not achievable without adequate consideration
of the ambient conditions such as the magnetic field configuration or gas
distribution. In a first step, we present a model that can explain the diffuse
gamma-ray emission as measured by H.E.S.S. for small longitudes in the Galactic
Center region but comes to grief with higher longitudes. The model is given via
the solution of a transport equation that allows for a radial dependency of the
mass distribution. In order to move from this semi-analytical approximation
toward a full understanding of the PeVatron signature, we present a new 3D
analytical model of the gas distribution in the Central Molecular Zone (CMZ).
Furthermore, we derive for the first time a 3D model of the magnetic field
configuration and strength in the CMZ, which is analytical and divergence-free.
The model is built via a combination of a model for the diffuse inter-cloud
medium, local molecular clouds and non-thermal filaments at which local
information are based on investigations from previous works and the molecular
gas density. It can be shown that without an efficient longitudinal CR
entrapment, a single source at the center does not facilely suffice the diffuse
gamma-ray detection. Further, we show that the new magnetic field model GBFD19
is compatible with recent polarization data and has a significant impact on the
longitudinal profiles of CR propagation.
