# Probing galactic cosmic ray distribution with TeV gamma-ray sky

## TL;DR

This paper investigates how TeV gamma-ray observations can constrain the distribution of cosmic rays in the Galaxy, using data from multiple observatories to differentiate between various cosmic ray distribution models.

## Contribution

It demonstrates that current TeV gamma-ray sky measurements can already distinguish among different hypotheses for cosmic ray distribution in the Galaxy.

## Key findings

- Experimental gamma-ray data can discriminate between cosmic ray distribution models.
- Including unresolved sources strengthens the constraints on cosmic ray distribution.
- Current observations are sufficient to test hypotheses about cosmic ray spatial distribution.

## Abstract

The distribution of cosmic rays in the Galaxy at energies above few TeVs is still uncertain and this affects the expectations for the diffuse gamma flux produced by hadronic interactions of cosmic rays with the interstellar gas. We show that the TeV gamma-ray sky can provide interesting constraints. Namely, we compare the flux from the galactic plane measured by Argo-YBJ, HESS, HAWC and Milagro with the expected flux due to diffuse emission and point-like and extended sources observed by HESS showing that experimental data can already discriminate among different hyphoteses for cosmic ray distribution. The constraints can be strengthened if the contribution of sources not resolved by HESS is taken into account.