On the surface brightness radial profile of the extended $\gamma$-ray sources

Abstract

The morphology of the extended $\gamma$-ray source is governed by the propagation process of parent relativistic particles. In this paper, we investigate the surface brightness radial profile of extended $\gamma$-ray sources illuminated by cosmic ray protons and electrons, considering the radiation mechanisms, projection effects, and the response of instruments. We found that the parent particle species and the propagation process can cause considerable differences in the observed radial profiles. Thus, the surface brightness profile can be used as a unique tool to identify the radiation mechanism and the propagation process of the parent particles. In addition, We also discuss the possible implications regarding the latest discoveries from very/ultra-high energy $\gamma$-ray instruments like LHAASO and HAWC.

Accepted for publication in SCIENCE CHINA Physics, Mechanics & Astronomy (SCPMA)

References in corpus (5)

• Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
• First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies
• 3HWC: The Third HAWC Catalog of Very-High-Energy Gamma-ray Sources
• A radiation transfer model for the Milky-Way: I. Radiation fields and application to High Energy Astrophysics
• Constraining the magnetic field in the TeV halo of Geminga with X-ray Observation

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• Measurement of Cosmic-Ray Density in the Spiral Arms toward Galactic Anticenter
• Investigating the emission signatures of pulsar halo candidate HESS J1813-126