Constraints on the TeV source population and its contribution to the galactic diffuse TeV emission

TL;DR

This paper estimates how unresolved TeV gamma-ray sources contribute significantly to the diffuse galactic TeV emission, using recent HESS observations and modeling their luminosity and number distributions.

Contribution

It introduces a detailed analysis of the HESS source population's luminosity function and predicts their contribution to diffuse emission and future detections.

Findings

Unresolved sources could account for a large part of the Milagro diffuse TeV emission.

The number-intensity relation for HESS sources is characterized.

Predictions for source detections by Veritas, Milagro, and HAWC are provided.

Abstract

The detection by the HESS atmospheric Cerenkov telescope of fourteen new sources from the Galactic plane makes it possible to estimate the contribution of unresolved sources like those detected by HESS to the diffuse Galactic emission measured by the Milagro Collaboration. The number-intensity relation and the luminosity function for the HESS source population are investigated. By evaluating the contribution of such a source population to the diffuse emission we conclude that a significant fraction of the TeV energy emission measured by the Milagro experiment could be due to unresolved sources like HESS sources. Predictions concerning the number of sources which Veritas, Milagro, and HAWC should detect are also given.