Speaker
Description
Using the publicly available observational data from the LHAASO, we conducted a detailed study of the gamma-ray emission properties of the source 1858+0330 in the TeV energy range. The analysis jointly utilized full-array observational data from the Water Cherenkov Detector Array (WCDA, using the Cod version data covering 1–25 TeV and divided into 7 energy bins) and the Kilometer Square Array (KM2A, using data processed with charged particle screening (CPC cut) covering energies above 25 TeV). The observation periods spanned from March 5, 2021, to July 31, 2025, for WCDA and from July 20, 2021, to July 31, 2025, for KM2A, with total exposure times of approximately 1609 days and 1472 days, respectively. Using a multi-component likelihood fitting method, we subtracted the isotropic background and diffuse gamma-ray templates to fit the spatial morphology and energy spectrum of the source, thereby obtaining the gamma-ray emission spectrum of 1858+0330 in the TeV range. The results reveal distinct radiative properties across different energy bands, with the WCDA and KM2A data connecting smoothly at the transition energy. This study provides important insights for understanding the radiation mechanisms and the nature of very-high-energy gamma-ray emission from this source.
