EDGE: a code to calculate diffusion of cosmic-ray electrons and their gamma-ray emission

Abstract

The positron excess measured by PAMELA and AMS can only be explained if there is one or several sources injecting them. Moreover, at the highest energies, it requires the presence of nearby (∼hundreds of parsecs) and middle age (maximum of ∼hundreds of kyr) source. Pulsars, as factories of electrons and positrons, are one of the proposed candidates to explain the origin of this excess. To calculate the contribution of these sources to the electron and positron flux at the Earth, we developed EDGE (Electron Diffusion and Gamma rays to the Earth), a code to treat diffusion of electrons and compute their diffusion from a central source with a flexible injection spectrum. We can derive the source's gamma-ray spectrum, spatial extension, the all-electron density in space and the electron and positron flux reaching the Earth. We present in this contribution the fundamentals of the code and study how different parameters affect the gamma-ray spectrum of a source and the electron flux measured at the Earth.

Constraining the Origin of Local Positrons with HAWC TeV Gamma-Ray Observations of Two Nearby Pulsar Wind Nebulae

“…HAWC carried out morphological and spectral studies using the 17 moths dataset of the Geminga and PSR B0656+14 region. These studies provide information about the diffusion co-PoS(IFS2017)011 efficient and gamma-ray spectrum which can be used as input parameters for the EDGE code [13]. EDGE takes into account the theory of electron diffusion, and computes the expected positron flux produced at the Earth by a pulsar.…”

Constraining the Origin of Local Positrons with HAWC TeV Gamma-Ray Observations of Two Nearby Pulsar Wind Nebulae

“…These studies provide information about the diffusion coefficient and gamma-ray spectrum which can be used as input parameters for the EDGE code [17]. EDGE takes into account the theory of electron diffusion, and computes the expected positron flux produced at the Earth by a pulsar.…”

ICRC Rapporteur: Space Based Gamma-ray Astronomy

“…There is tremendous momentum behind open source science and open source tools and our community should embrace this and encourage it. [55] presented EDGE 5 , a diffusion and emission simulations package. [56] detailed an analysis package designed to aid in the analysis of Fermi-LAT data called fermipy 6 .…”