Galactic Center Studies with CTA-LST-1

The Galactic Center region is known to host a wide variety of very-high-energy gamma-ray sources. In 2018 the prototype of the Large-Sized Telescope (LST-1) for CTA was inaugurated, and has been regularly observing the Galactic Center since 2021. To observe the Galactic Center in the southern sky, LST-1, located in the Northern hemisphere, requires an observation mode at a low telescope elevation. In this study, we assessed the performance of LST-1 at the large zenith angle, based both on simulations and observational data for the standard candle Crab Nebula. Analyzing LST-1 data from the Galactic Center observations, we obtained the spectral energy distributions of Sagittarius A* and G0.9+0.1, which were comparable with the results from the current imaging atmospheric Cherenkov telescopes, with a broad energy coverage owing to the large-zenith-angle observation and the low energy threshold of LST-1.