Abstract

Contributed Talk - Splinter NonThermalAccel   (MW-1250)

Reproducing the Multiwavelength Galactic Center Gamma-Ray Emission with a Composite PeVatron and Realistic Cosmic-Ray Dynamics

Jorge Cuadra
UAI, Chile / MPE, Germany

High-energy (HE) and very-high-energy (VHE) gamma-ray observations of the Galactic center reveal extended emission that is strongly correlated with the morphology of the central molecular zone (CMZ). This emission is widely attributed to hadronic interactions between cosmic rays (CRs) and ambient gas, fueled by nature's extreme particle accelerators ("PeVatrons"). However, most transport models rely on overly simplistic CR dynamics. In this work, we employ numerical simulations to investigate whether more realistic CR transport—incorporating distinct diffusion regimes inside and outside the CMZ, alongside polar advection mimicking Galactic outflows—can explain these high-energy signals. We simulate CR populations injected from localized cosmic accelerators (the Arches, Quintuplet, and nuclear stellar clusters, plus the Sgr A East supernova remnant) embedded within a diffuse background Galactic CR "sea". Evaluating these models against 3D gas distributions with and without an inner cavity, we present a unified framework that can reconcile both Fermi-LAT (HE) and HESS (VHE) observations. Our results suggest that reproducing the multiwavelength data favors a ring-like gas distribution with an inner cavity, active injection from the multiple considered stellar and remnant sources, and a background CR sea intensity comparable to that measured in the Solar System. These findings support an interpretation where the Galactic PeVatron is a composite population rather than a single central engine, while remaining compatible with constraints from Sagittarius A*.