Observation of the γ-ray Emission from W43 with LHAASO

In this paper, we report the detection of the very-high-energy (VHE, 100\ GeV < E < 100\ TeV) and ultra-high-energy (UHE, E > 100\ TeV) γ-ray emissions from the direction of the young star-forming region W43, observed by the Large High Altitude Air Shower Observation (LHAASO). The extended γ-ray source was detected with a significance of ~16\,σ by KM2A and ~17\,σ by WCDA, respectively. The angular extension of this γ-ray source is about 0.5 degrees, corresponding to a physical size of about 50 pc. We discuss the origin of the γ-ray emission and possible cosmic ray acceleration in the W43 region using multi-wavelength data. Our findings suggest that W43 is likely another young star cluster capable of accelerating cosmic rays (CRs) to at least several hundred TeV.