Geminga contribution to the cosmic-ray positron excess according to the gamma-ray observations

Abstract

We attempt to interpret the cosmic-ray positron excess by injection from the nearby pulsar Geminga, assuming a two-zone diffusion scenario and an injection spectrum with a low energy cutoff. Since the high energy positrons and electrons from Geminga can induce $\gamma$ rays via inverse Compton scattering, we take into account the extended $\gamma$-ray observations around Geminga from HAWC for $\sim 10$ TeV and from Fermi-LAT for $\mathcal{O}(10)$ GeV. According to the extended $\gamma$-ray observation claimed by an analysis of Fermi-LAT data, we find that Geminga could explain the positron excess for a $30\%$ energy conversion efficiency into positrons and electrons. However, based on the constraint on the extended $\gamma$ rays given by another Fermi-LAT analysis, positrons from Geminga would be insufficient to account for the positron excess. A further robust analysis of Fermi-LAT data for the extended $\gamma$ rays would be crucial to determine whether Geminga can explain the positron excess or not.

arXiv comment14 pages, 2 figures; revisions to match the published version

References in corpus (31)

• The ATNF Pulsar Catalogue
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• Observation of an anomalous positron abundance in the cosmic radiation
• Production and propagation of cosmic-ray positrons and electrons
• Measurement of separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope
• Pulsars as the Sources of High Energy Cosmic Ray Positrons
• Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
• TeV Gamma Rays from Geminga and the Origin of the GeV Positron Excess
• New Positron Spectral Features from Supersymmetric Dark Matter - a Way to Explain the PAMELA Data?
• PAMELA data and leptonically decaying dark matter
• High Energy Positrons From Annihilating Dark Matter
• Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622 + 3749 Observed by LHAASO-KM2A
• Detection of a $\gamma$-ray halo around Geminga with the Fermi-LAT and implications for the positron flux
• Lessons from HAWC PWNe observations: the diffusion constant is not a constant; Pulsars remain the likeliest sources of the anomalous positron fraction; Cosmic rays are trapped for long periods of time in pockets of inefficient diffusion
• Two-zone diffusion of electrons and positrons from Geminga explains the positron anomaly
• Pulsar interpretation for the AMS-02 result
• Positron flux and gamma-ray emission from Geminga pulsar and pulsar wind nebula
• Implications of the AMS-02 positron fraction in cosmic rays
• Cosmic-Ray Propagation in Light of Recent Observation of Geminga
• Contribution of pulsars to cosmic-ray positrons in light of recent observation of inverse-Compton halos
• Measuring the Local Diffusion Coefficient with H.E.S.S. Observations of Very High-Energy Electrons
• GeV observations of the extended pulsar wind nebulae constrain the pulsar interpretations of the cosmic-ray positron excess
• Constraining the magnetic field in the TeV halo of Geminga with X-ray Observation
• Klein-Nishina effect and the cosmic ray electron spectrum
• Studying the Milky Way Pulsar Population with Cosmic-Ray Leptons
• Non-thermal emission from old supernova remnants
• Reanalyze the pulsar scenario to explain the cosmic positron excess considering the recent developments
• Features in the Spectrum of Cosmic-Ray Positrons from Pulsars
• Pulsar interpretation of the lepton spectra measured by AMS-02
• Test of the superdiffusion model in the interstellar medium around the Geminga pulsar
• Interpretation of the puzzling gamma-ray spectrum of the Geminga halo

Cited by in corpus (1)

• Constraining the slow-diffusion zone size and electron injection spectral index for the Geminga pulsar halo