2024/07/15 by Yingying Guo, Qiang Yuan, Guo, YingYing +1
Earth and Planetary Sciences · #Earthquake Detection and Analysis #FOS: Physical sciences #Geophysics and Gravity Measurements #High Energy Astrophysical Phenomena (astro-ph.HE) #Seismic Waves and Analysis
paper · pdf · doi:10.48550/arxiv.2407.10705
openalex publication_date 2024/07/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The extended γ-ray halos around pulsars are unique probe of transportation of high-energy electrons (and positrons) in vicinities of such pulsars. Observations of morphologies of several such halos indicate that particles diffuse very slowly around pulsars, compared with that in the Milky Way halo. The energy-dependent morphologies are expected to be very important in studying the energy-dependence of the diffusion coefficient. In this work we point out that the spectrum of high-energy electrons takes effect in shaping the γ-ray morphologies at the ultra-high-energy bands, and thus results in a degeneracy between the electron spectrum and the energy-dependence of the diffusion coefficient. The reasons for such a degeneracy include both the Klein-Nishina effect of the inverse Compton scattering and the curvature (if any) of the electron spectrum. It it thus necessary to take into account the spectral shape of electrons when deriving the energy-dependence of diffusion coefficient using ultra-high-energy γ-ray measurements of extended pulsar halos.