Multi-wavelength study of a TeV-unidentified source near a supernova remnant

We studied a TeV source without clear counterparts in other wavelengths but close to the supernova remnant G335.2+0.1 (Oka et al. 2025, ApJ; ADS). We used radio continuum, radio lines, X-rays, and gamma-rays to understand what is going on in this interesting system. What was unique was, in this system, we can trace some physical processes which are not available in most sources, like the particle diffusion from the accelerator to a cloud nearby, and the gamma-ray emission consisting of the accelerator and illuminated cloud. Combining these properties, we were able to infer that the maximum energy of accelerated particles in the past probably reaches ~PeV.