SAG-SCI: the Real-time, High-level Analysis Software for Array Control and Data Acquisition of the Cherenkov Telescope Array Observatory
Gabriele Panebianco, Nicolò Parmiggiani, Andrea Bulgarelli, Ambra Di Piano, Luca Castaldini, Valentina Fioretti, Giovanni De Cesare, Sami Caroff, Pierre Aubert, Gilles Maurin, Vincent Pollet, Thomas Vuillaume, Igor Oya, Cristian Vignali
Published: 2025/9/23
Abstract
The Cherenkov Telescope Array Observatory (CTAO) is going to be the leading observatory for very-high-energy gamma-rays over the next decades. Its unique sensitivity, wide field of view, and rapid slewing capability make the CTAO especially suited to study transient astrophysical phenomena. The CTAO will analyse its data in real-time, responding to external science alerts on transient events and issuing its own. The Science Alert Generation (SAG) automated pipeline, a component of the Array Control and Data Acquisition (ACADA) software, is designed to detect and issue candidate science alerts. In this work, we present the current development status of SAG-SCI, the SAG component responsible for the real-time, high-level analysis of CTAO data. The SAG-SCI pipelines receive gamma-ray data from multiple reconstruction lines, merge them, store them in a database, and trigger several parallel scientific analyses on the latest data. These analyses include estimating target significance and flux, producing sky maps and light curves, and conducting blind searches for sources within the field of view. We execute SAG-SCI on a set of simulated gamma-ray data, detecting the simulated sources and accurately reconstructing their flux and position. We also estimate the systematic errors introduced by the analysis and discuss the results in relation to the generation of candidate science alerts.