1 research outputs found
Cross-calibration and combined analysis of the CTA-LST prototype and the MAGIC telescopes
The Cherenkov Telescope Array (CTA) is the next-generation gamma-ray observatory that is
expected to reach one order of magnitude better sensitivity than that of current telescope arrays.
The Large-Sized Telescopes (LSTs) have an essential role in extending the energy range down to
20 GeV. The prototype LST (LST-1) proposed for CTA was built in La Palma, the northern site
of CTA, in 2018. LST-1 is currently in its commissioning phase and moving towards scientific
observations. The LST-1 camera consists of 1855 photomultiplier tubes (PMTs) which are
sensitive to Cherenkov light. PMT signals are recorded as waveforms sampled at 1 GHz rate with
Domino Ring Sampler version 4 (DRS4) chips. Fast sampling is essential to achieve a low energy
threshold by minimizing the integration of background light from the night sky. Absolute charge
calibration can be performed by the so-called F-factor method, which allows calibration constants
to be monitored even during observations. A calibration pipeline of the camera readout has been
developed as part of the LST analysis chain. The pipeline performs DRS4 pedestal and timing
corrections, as well as the extraction and calibration of charge and time of pulses for subsequent
higher-level analysis. The performance of each calibration step is examined, and especially charge
and time resolution of the camera readout are evaluated and compared to CTA requirements. We
report on the current status of the calibration pipeline, including the performance of each step
through to signal reconstruction, and the consistency with Monte Carlo simulation