Stability and precision studies of the LST-1 telescope

Abstract

The Large-Sized Telescope prototype (LST-1) is crucial in the development of the Cherenkov Telescope Array (CTA). This study aims to improve the understanding of the stability and pointing precision of the LST-1. Using data from Crab Nebula, Markarian 421 (Mrk 421) and BL Lacertae (BL Lac), we analyze, for different timescales, whether the distributions of the reconstructed positions of the sources were centered on the expected positions. Additionally, we study the gamma-ray Point Spread Function (PSF) of the telescope to determine whether the spread of the reconstructed directions is consistent with those obtained from simulations. This analysis confirms the existence of a small pointing error which varies with time along the studied sample, in timescales larger than the run duration. Moreover, all results are consistent with a variable Gaussian mispointing for shorter timescales with a σ ranging from 0.63 ± 0.06 to 3.06 ± 0.06 arcmin, exhibiting a strong dependency on the telescope’s position.