Highlights of LHAASO science results

Abstract

The Large High Altitude Air Shower Observatory (LHAASO) is a complex of extensive air shower (EAS) detector array for very-high energy and ultra-high energy γ-ray observation and cosmic ray studies. LHAASO was completed its construction and has been starting the full-duty operation in July 2021 at Mt Haizi 4,410 meters above sea level, China. With the data collected in 2020, LHAASO found a dozen UHE gamma-ray sources with high significance (> 7σ). Their energy spectra are found extended to about 1 PeV without obvious cut-off. LHAASO also recorded the unprecedent highest energy photon with the energy of 1.4 ± 0.13 PeV. These findings confirmed the existence of PeV particle accelerators in the Milk Way and opened up an era of UHE gamma-ray astronomy. LHAASO measured the energy spectrum of the Crab Nebula from 0.5 TeV up to 1.1 PeV for the first time. LHAASO achieved the absolute energy scale calibration in cosmic ray shower measurements at 21±6 TeV by measuring the Moon shadow drifting in the geo-magnetic field using WCDA. In this proceeding, we summarize the status of LHAASO experiment and highlight the γ-ray results and cosmic ray progresses.