Naslov
Performance of the Cherenkov Telescope Array in the presence of clouds

Autori
Pecimotika, Mario ; Adamczyk, Katarzyna ; Dominis Prester, Dijana ; Gueta, Orel ; Hrupec, Dario ; Maier, Gernot ; Mićanović, Saša ; Pavletić, Lovro ; Sitarek, Julian ; Sobczyńska, Dorota ; Szanecki, Michał

Kolaboracija
The CTA consortium

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of 37th International Cosmic Ray Conference PoS(ICRC2021) / - , 2021

Skup
37th International Cosmic Ray Conference (ICRC 2021)

Mjesto i datum
Berlin, Njemačka, 12.07.2021. - 23.07.2021

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Cherenkov telescopes, clouds, CTA, MODTRAN, Monte Carlo simulations

Sažetak
The Cherenkov Telescope Array (CTA) is the future ground-based observatory for gamma-ray astronomy at very high energies. The atmosphere is an integral part of every Cherenkov telescope. Different atmospheric conditions, such as clouds, can reduce the fraction of Cherenkov photons produced in air showers that reach ground-based telescopes, which may affect the performance. Decreased sensitivity of the telescopes may lead to misconstructed energies and spectra. This study presents the impact of various atmospheric conditions on CTA performance. The atmospheric transmission in a cloudy atmosphere in the wavelength range from 203 nm to 1000 nm was simulated for different cloud bases and different optical depths using the MODerate resolution atmospheric TRANsmission (MODTRAN) code. MODTRAN output files were used as inputs for generic Monte Carlo simulations. The analysis was performed using the MAGIC Analysis and Reconstruction Software (MARS) adapted for CTA. As expected, the effects of clouds are most evident at low energies, near the energy threshold. Even in the presence of dense clouds, high-energy gamma rays may still trigger the telescopes if the first interaction occurs lower in the atmosphere, below the cloud base. A method to analyze very high-energy data obtained in the presence of clouds is presented. The systematic uncertainties of the method are evaluated. These studies help to gain more precise knowledge about the CTA response to cloudy conditions and give insights on how to proceed with data obtained in such conditions. This may prove crucial for alert-based observations and time-critical studies of transient phenomena.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA