Systematic effects in the estimate of the local gamma-ray emissivity

2011/09/05 by Timur Delahaye, Delahaye, Timur, P. Salati +8
Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Particle Detector Development and Performance #Radioactive Decay and Measurement Techniques #astro-ph.GA #astro-ph.HE

paper · pdf · doi:10.48550/arxiv.1109.0834

arxiv created 2011/09/05 · openalex publication_date 2011/09/05 · arxiv updated 2011/09/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We show in this letter that estimates of the local emissivity of γ-rays in the GeV-TeV range suffer uncertainties which are of the same order of magnitude as the current Fermi results. Primary cosmic-ray fluxes, cosmic-ray propagation, interstellar helium abundance and γ-ray production crosssections all affect the estimate of this quantity. We also show that the so-called nuclear enhancement factor -- though widely used so far to model the γ-ray emissivity -- is no longer a relevant quantity given the latest measurements of the primary cosmic ray proton and helium spectra.

Related

• Local H~\sc i emissivity measured with the \it Fermi-LAT and implications for cosmic-ray spectra
• Determining the Spectrum of Cosmic Rays in Interstellar Space from the Diffuse Galactic Gamma-Ray Emissivity
• On the Physics Connecting Cosmic Rays and Gamma Rays: Towards Determining the Interstellar Cosmic Ray Spectrum
• Local interstellar cosmic-ray spectra derived from gamma-ray emissivities
• Revised Upper Limits of the Diffuse Tev Gamma Rays from the Galactic Planes with the Tibet II and III Air Shower Arrays