The Second LHAASO Collaboration Conference in 2026 & The Academic Symposium for the 10th Anniversary of the LHAASO collaboration

Using the publicly available observational data from LHAASO, we conducted a detailed study of the gamma-ray emission properties of the source 1858+0330 in the TeV energy range. This analysis utilizes the latest data set: for the Water Cherenkov Detector Array (WCDA, using the Cod version data covering 1–25 TeV and divided into 7 energy bins), the observation period is from March 5, 2021 to July 31, 2025, with a total exposure of approximately 1484 days; for the Kilometer Square Array (KM2A, using data processed with charged particle screening (CPC cut) covering energies above 25 TeV), the observation period extends to January 31, 2026, with a total exposure of approximately 1572 days. 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.