2025PASP..137e4102W

With the advancement of detector technology, significant progress has been made in understanding Pulsar Wind Nebulae (PWNe) through multi-wavelength observations, particularly in the X-ray and TeV γ-ray bands. While young PWNe have been extensively studied, PWNe with ages around 10 kyr remain relatively underexplored. In this study, we investigate the radiative properties of four selected PWNe associated with the γ-ray sources HESS J1420-607, HESS J1418-609, HESS J1427-608, and HESS J1303-631 using a time-dependent electron population model. High-energy electrons and positrons are injected into the nebula, producing multi-wavelength non-thermal emission through synchrotron radiation and inverse Compton scattering. Based on comparisons with previous studies, we assume that four sources have not yet been compressed by the reverse shock, with estimated ages around 7-8 kyr. The injected particles follow a broken power-law distribution, with spectral indices consistent with previous studies. We find that the four nebulae are currently particle-dominated systems with magnetic field strengths ranging from a few μG to 10 μG, in agreement with theoretical expectations for PWNe at similar evolutionary stages. Our results support the scenario that all four sources originate with PWNe, as their multi-wavelength nonthermal emission can be reproduced with reasonable parameters.