A pulsar wind nebula origin of the LHAASO-detected UHE gamma-ray sources

Abstract

The recent measurement by LHAASO of gamma-ray emission extending up to 100s of TeV from multiple Galactic sources represents a major observational step forward in the search for the origin of the Galactic cosmic rays. The burning question is if this ultra-high-energy emission is associated to acceleration of protons and/or nuclei to PeV energies, or can be associated to PeV-electron accelerators. A strong Klein-Nishina suppression of inverse Compton emission at these energies is unavoidable, nevertheless we show here that inverse Compton emission can provide a natural explanation of the measured emission, and that an association to the established PeV-electron accelerating source class of pulsar wind nebulae is also rather natural. However, a clear distinction between different models requires taking into account multi-wavelength data, having good knowledge about the local environmental conditions and, in some cases, to perform multi-source modeling.