Prospects for the detection of synchrotron halos around middle-age pulsars

TL;DR

This paper explores the potential of upcoming gamma-ray missions to detect synchrotron halos around middle-age pulsars, which could shed light on the origin of cosmic-ray positrons above 10 GeV.

Contribution

It demonstrates that proposed astrophysics missions like AMEGO and AdEPT can detect synchrotron halos around specific pulsars, advancing understanding of cosmic-ray positron sources.

Findings

AMEGO and AdEPT can detect synchrotron halos around Geminga and Monogem pulsars.

Identification of promising pulsars for synchrotron halo detection.

Implications for understanding the positron excess in cosmic rays.

Abstract

The origin of cosmic-ray positrons detected with an energy above 10 GeV is one of the most intriguing mysteries in Astroparticle Physics. Different interpretations have been invoked to solve this puzzle such as pulsar wind nebulae (PWNe), supernovae remnants or interactions of dark matter particles. The HAWC and Milagro experiments have measured an extended emission of photons above 10 TeV in the direction of Geminga and Monogem PWNe which can be interpreted by photons emitted through inverse Compton scattering by positrons and electrons accelerated by these sources. These HAWC and Milagro detections are extremely important to estimate the PWN contribution to the positron excess. Positrons and electrons emitted by PWNe and injected in the interstellar medium can produce photons with an energy between radio and X-ray through synchrotron radiation with the Galactic magnetic field. In this white paper we show that Astrophysics Probe mission concepts, such as AMEGO (the All-sky Medium Energy Gamma-ray Observatory) and AdEPT (The Advanced Energetic Pair Telescope), are suitable to detect the synchrotron halos from Monogem and Geminga PWNe and we will report the list of the most promising PWNe that AMEGO could be able to detect.