Effect of the uncertainty in the hadronic interaction models on the estimation of the sensitivity of the Cherenkov Telescope Array. (arXiv:2105.05822v1 [astro-ph.IM])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ohishi_M/0/1/0/all/0/1">Michiko Ohishi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arbeletche_L/0/1/0/all/0/1">Luan Arbeletche</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Souza_V/0/1/0/all/0/1">Vitor de Souza</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maier_G/0/1/0/all/0/1">Gernot Maier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernlohr_K/0/1/0/all/0/1">Konrad Bernlöhr</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olaizola_A/0/1/0/all/0/1">Abelardo Moralejo Olaizola</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bregeon_J/0/1/0/all/0/1">Johan Bregeon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arrabito_L/0/1/0/all/0/1">Luisa Arrabito</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yoshikoshi_T/0/1/0/all/0/1">Takanori Yoshikoshi</a>
Imaging Atmospheric Cherenkov Telescopes (IACTs) are ground-based indirect
detectors for cosmic gamma rays with energies above tens of GeV. The major
backgrounds for gamma-ray observations in IACTs are cosmic-ray charged
particles. The capability to reject these backgrounds is the most important
factor determining the gamma-ray sensitivity of IACT systems. Monte Carlo
simulations are used to estimate the residual background rates and sensitivity
of the systems during the design and construction phase. Uncertainties in the
modeling of high-energy hadronic interactions of cosmic rays with nuclei in the
air propagate into the estimates of residual background rates and subsequently
into the estimated instrument sensitivity. We investigate the influence of the
difference in the current hadronic interaction models on the estimated
gamma-ray sensitivity of the Cherenkov Telescope Array using four interaction
models (QGSJET-II-03, QGSJET-II-04, EPOS-LHC, and SIBYLL2.3c) implemented in
the air shower simulation tool CORSIKA. Variations in background rates of up to
a factor 2 with respect to QGSJET-II-03 are observed between the models, mainly
due to differences in the $pi^0$ production spectrum. These lead to ~30%
differences in the estimated gamma-ray sensitivity in the 1 – 30 TeV region,
assuming a 50-hour observation of a gamma-ray point-like source. The presented
results also show that IACTs have a significant capability in the verification
of hadronic interaction models.
Imaging Atmospheric Cherenkov Telescopes (IACTs) are ground-based indirect
detectors for cosmic gamma rays with energies above tens of GeV. The major
backgrounds for gamma-ray observations in IACTs are cosmic-ray charged
particles. The capability to reject these backgrounds is the most important
factor determining the gamma-ray sensitivity of IACT systems. Monte Carlo
simulations are used to estimate the residual background rates and sensitivity
of the systems during the design and construction phase. Uncertainties in the
modeling of high-energy hadronic interactions of cosmic rays with nuclei in the
air propagate into the estimates of residual background rates and subsequently
into the estimated instrument sensitivity. We investigate the influence of the
difference in the current hadronic interaction models on the estimated
gamma-ray sensitivity of the Cherenkov Telescope Array using four interaction
models (QGSJET-II-03, QGSJET-II-04, EPOS-LHC, and SIBYLL2.3c) implemented in
the air shower simulation tool CORSIKA. Variations in background rates of up to
a factor 2 with respect to QGSJET-II-03 are observed between the models, mainly
due to differences in the $pi^0$ production spectrum. These lead to ~30%
differences in the estimated gamma-ray sensitivity in the 1 – 30 TeV region,
assuming a 50-hour observation of a gamma-ray point-like source. The presented
results also show that IACTs have a significant capability in the verification
of hadronic interaction models.
http://arxiv.org/icons/sfx.gif
