Study of TeV halo candidate LHAASO J1849+0851 with LHAASO data

Gamma-ray halos around pulsars provide critical insights into cosmic-ray transport processes in localized regions of the Galaxy. Using over 3 years of LHAASO data, a new extended $\gamma$-ray source positionally coincident with the middle-aged pulsar J1846+0919 is detected with a significance of 9.6$\sigma$. Its surface brightness profile can be interpreted by a diffusion model with $\theta_d=2^{\circ}.42\pm0^{\circ}.70$, corresponding to a diffusion coefficient several times larger than that of the Geminga halo. The $\gamma$-ray spectrum can be described by a hard power law with a high-energy exponential cutoff at $19.5\pm2.8$~TeV. The absence of SNR counterparts and similar characteristics to known pulsar halos support its identification as a pulsar halo, making it the first pulsar halo candidate detected in the inner Galaxy.