VHE γ-ray observations of bright BL Lacs with the Large-Sized Telescope prototype (LST-1) of the CTAO

Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based <em>γ</em>-ray observatory operating in the energy range from 20GeV up to 300TeV, with two sites in La Palma (Spain) and Paranal (Chile). It will consist of telescopes of three sizes, covering different part...

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Detalles Bibliográficos
Autores: Aguasca Cabot, Arnau, Ribó Gomis, Marc, Paredes i Poy, Josep Maria, Pihet, Marine, Bordas Coma, Pol, CTAO-LST Collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/228171
Acceso en línea:https://hdl.handle.net/2445/228171
Access Level:acceso abierto
Palabra clave:Telescopis
Galàxies
Astronomia de raigs gamma
Telescopes
Galaxies
Gamma ray astronomy
Descripción
Sumario:Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based <em>γ</em>-ray observatory operating in the energy range from 20GeV up to 300TeV, with two sites in La Palma (Spain) and Paranal (Chile). It will consist of telescopes of three sizes, covering different parts of the large energy range. We report on the performance of Large-Sized Telescope prototype (LST-1) in the detection and characterization of extragalactic <em>γ</em>-ray sources, with a focus on the reconstructed <em>γ</em>-ray spectra and variability of classical bright BL Lacertae objects, which were observed during the early commissioning phase of the instrument. LST-1 data from known bright <em>γ</em>-ray blazars ─ Markarian 421, Markarian 501, 1ES 1959+650, 1ES 0647+250, and PG 1553 + 113 ─ were collected between 2020 July 10, and 2022 May 23, covering a zenith angle range of 4∘ to 57∘. The reconstructed light curves were analysed using a Bayesian block algorithm to distinguish the different activity phases of each blazar. Simultaneous Fermi-LAT data were utilized to reconstruct the broad-band <em>γ</em>-ray spectra for the sources during each activity phase. High-level reconstructed data in a format compatible with gammapy are provided together with measured light curves and spectral energy distributions (SEDs) for several bright blazars and an interpretation of the observed variability in long and short time-scales. Simulations of historical flares are generated to evaluate the sensitivity of LST-1. This work represents the first milestone in monitoring bright BL Lacertae objects with a CTAO telescope.