A GeV PWN Candidate in the PSR J1135--6055/G293.8+0.6 Field

Abstract

We present a \textit{Fermi} Large Area Telescope (LAT) study of PSR~J1135--6055 and the composite supernova remnant (SNR) G293.8+0.6. MeerKAT radio observations reveal a bright central plerion within the faint SNR shell, while Chandra observations detect a compact nebula around the pulsar. Together, these observations establish the presence of a PWN within G293.8+0.6. Our analysis of the 20~GeV--1~TeV LAT data yields a point-like excess with $\mathrm{TS}=26.30$ and photon index $Γ=1.63\pm0.33$. Its best-fit position is consistent with the pulsar within the 95\% statistical localization region, and neither the uniform-disk nor Gaussian model is favored, providing no evidence for significant extension. A one-zone leptonic model, together with an independent jet component, reproduces the multiwavelength observations. In this model, the GeV photons are produced mainly by inverse-Compton scattering from relativistic electrons and positrons. Given its positional agreement with the pulsar/PWN and broadband interpretation, we regard the LAT point source as a GeV PWN candidate.