Probing the PeVatron Candidate LHAASO J2108+5157 through CO, H I, and Infrared Observations

• Eduardo de la Fuente (Universidad de Guadalajara)

Room: 606호 The LHAASO observatory discovered the ultra-high-energy gamma-ray source LHAASO J2108+5157, while subsequent HAWC observations detected significant emission between 3 and 146 TeV, favoring an extended morphology and a power-law spectrum consistent with a PeVatron candidate. However, the absence of a firmly identified counterpart and indications of possible hadronic illumination of molecular and atomic gas leave the nature of the source uncertain. In this contribution, we present new Nobeyama 12,13CO (J=1→0) observations toward LHAASO J2108+5157, combined with DRAO/HI4PI H,I and optical-infrared data, to investigate the surrounding interstellar environment and test hadronic emission scenarios through target-gas constraints. We additionally discuss potential counterparts associated with the gamma-ray emission region