131. Study of Ultra-High Energy Cosmic Ray composition using Telescope Array’s Middle Drum detector and surface array in hybrid modeR.U. Abbasi, Jon Paul Lundquist, 2015, original scientific article Abstract: Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.
Keywords: Ultra-High Energy Cosmic Rays, Cosmic ray composition, Atmospheric fluorescence, Extensive air shower array, Hybrid, Telescope Array
Published in RUNG: 24.04.2020; Views: 2975; Downloads: 0
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132. SEARCH FOR NEUTRINOS AT EXTREME ENERGIES WITH THE PIERRE AUGER OBSERVATORYMarta Trini, 2019, doctoral dissertation Abstract: The detection of Ultra-High-Energy (UHE) neutrinos around and above 10 18 eV (1 EeV) can be the key to
answering the long-standing question of the origin of the UHE cosmic rays. The Pierre Auger Observatory
is the largest experiment that can detect the extensive air showers produced when the cosmic rays and
neutrinos interact in the earth’s atmosphere. In particular, with the Infilled array of the Surface Detector
of the Pierre Auger Observatory we can detect sub-EeV neutrino-induced particle showers. In this thesis
we demonstrate that it is possible to discriminate neutrino-induced showers from the background showers
produced by the more numerous nucleonic cosmic rays. The sensitivity to neutrinos is enhanced in the
inclined directions with respect to the vertical to the ground, where cosmic ray-induced showers starting in
the upper layers of the atmosphere are dominated by the muonic component of the shower, while deeply-
penetrating neutrino showers in contrast exhibit a large electromagnetic component. Based on this idea in
this thesis we have developed a search procedure for UHE neutrinos that consists on selecting inclined
events in the Infilled array of the Pierre Auger Observatory in which the signals in the water-Cherenkov
stations are spread in time, characteristic of the presence of electromagnetic component in the shower. We
have established a complete chain of criteria to first select the inclined events among the sample of all
events triggering the Infilled array, and then identifying those that have a large electromagnetic component
at ground, and hence can be considered as neutrino candidates. We have identified a single variable, the
so-called area-over-peak averaged over all of the stations in each event, as a suitable observable for neutrino
identification purposes. The neutrino selection was established using extensive Monte Carlo simulations of
the neutrino-induced showers in the Infilled array of Auger as well as a fraction of the data assumed to
be totally constituted of background nucleonic cosmic rays. Using these neutrino simulations we have also
computed the exposure of the Infilled array to UHE neutrinos in the period 1 January 04 - 31 December 2017.
Associated systematic uncertainties on the exposure are also described. Expecting no candidate neutrinos in
the period up to 31 December 2017, and adopting a differential neutrino diffuse flux dN ν /dE ν = k E ν −2 in
the energy range from 0.05 to 1 EeV, we have obtained a 90% C.L. upper limit on the all neutrino flavor,
k 90 < 7.97 × 10 −8 GeV cm −2 s −1 sr −1 .
Keywords: astroparticles, astrophysical neutrinos, cosmic rays showers, Pierre Auger Observatory, Infilled
array
Published in RUNG: 03.10.2019; Views: 4805; Downloads: 147
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133. Raman LIDARs and atmospheric calibration along the line-of-sight of the Cherenkov Telescope ArraySamo Stanič, Longlong Wang, Marko Zavrtanik, 2019, published scientific conference contribution Abstract: The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for
gamma-ray astronomy at very-high energies. Employing more than 100 (north and south sites)
Imaging Atmospheric Cherenkov Telescopes in the northern and southern hemispheres, it was
designed to reach unprecedented sensitivity and energy resolution. Understanding and correcting
for systematic biases on the absolute energy scale and instrument response functions will be a cru-
cial issue for the performance of CTA. The Montpellier group and the Spanish/Italian/Slovenian
collaboration are currently building two Raman LIDAR prototypes for the online atmospheric cal-
ibration along the line-of-sight of the CTA. Requirements for such a solution include the ability
to characterize aerosol extinction at two wavelengths to distances up to 30 km with an accuracy
better than 5%, within exposure time scales of about a minute, steering capabilities and close
interaction with the CTA array control and data acquisition system as well as other auxiliary in-
struments. Our Raman LIDARs have design features that make them different from those used
in atmospheric science and are characterized by large collecting mirrors (∼2.5 m 2 ), liquid light-
guides that collect the light at the focal plane and transport it to the readout system, reduced
acquisition time and highly precise Raman spectrometers. The Raman LIDARs will participate in
a cross-calibration and characterization campaign of the atmosphere at the CTA North site at La
Palma, together with other site characterization instruments. After a one-year test period there, an
in-depth evaluation of the solutions adopted by the two projects will lead to a final Raman LIDAR
design proposal for both CTA sites.
Keywords: Raman lidar atmospheric calibration Cherenkov Telescope Array
Published in RUNG: 29.08.2019; Views: 3408; Downloads: 102
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134. Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layoutA. Acharyya, Samo Stanič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2019, original scientific article Keywords: very-high energy gamma-ray astronomy, Cherenkov Telescope Array, array layout optimisation, Monte Carlo studies
Published in RUNG: 18.04.2019; Views: 3068; Downloads: 0
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135. Testing the agreement between the Xmax distributions measured by the Pierre Auger and Telescope Array ObservatoriesV. De Souza, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Xmax distributions, Pierre Auger Observatory, Telescope Array
Published in RUNG: 19.02.2018; Views: 3759; Downloads: 179
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136. Report of the Telescope Array - Pierre Auger Observatory Working Group on Energy SpectrumDmitri Ivanov, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Darko Veberič, Serguei Vorobiov, Marta Trini, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Telescope Array, Pierre Auger Observatory, Energy Spectrum
Published in RUNG: 19.02.2018; Views: 3395; Downloads: 172
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137. Auger at the Telescope Array: toward a direct cross-calibration of surface-detector stationsS. Quinn, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Telescope Array, Pierre Auger Observatory, direct cross-calibration
Published in RUNG: 19.02.2018; Views: 3409; Downloads: 172
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138. First results from the AugerPrime engineering arrayZizhao Zong, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: AugerPrime, engineering array, Pierre Auger Observatory
Published in RUNG: 16.02.2018; Views: 3361; Downloads: 166
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139. Recent Results of the Auger Engineering Radio Array (AERA)Ewa M. Holt, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: Auger Engineering Radio Array (AERA), Pierre Auger Observatory, extensive air showers
Published in RUNG: 16.02.2018; Views: 3456; Downloads: 144
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140. Tools and Procedures for the CTA Array CalibrationMaria Concetta Maccarone, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution Keywords: CTA, array calibration, groups of telescopes
Published in RUNG: 16.02.2018; Views: 2859; Downloads: 149
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