Galactic Microquasar and Supernova Remnants Imprinting on Diffuse Neutrino and Gamma-Ray Sky

Abstract

Recent detections of Galactic diffuse neutrinos by IceCube and $γ$-rays by LHAASO offer direct probes into the origin of Galactic cosmic rays. Conventional diffuse templates typically assume a single cosmic-ray injection spectrum across a wide energy range, without accounting for independent contributions from distinct accelerator populations. Here, we present a numerical framework that models Galactic diffuse neutrino and $γ$-ray emission that incorporates contributions from both microquasar and supernova remnant populations. By anchoring CR injection to local observations and utilizing high-resolution 3D target gas distributions, our model suggests multi-population contributions to the diffuse sky: escaped cosmic rays from supernova remnants dominate below $\sim10\text{ TeV}$, while those from microquasars become the primary driver at higher energies. Our predicted neutrino flux agrees well with the recent 12-year IceCube measurements, establishing a physically motivated baseline for the diffuse hadronic background while leaving room for unresolved point-like sources. This flexible framework provides testable predictions for current and future multi-messenger observatories, accommodating diverse accelerator populations and updated observational constraints.