1,721,497 research outputs found
RESULTS FROM THE PIERRE AUGER OBSERVATORY
No full textThe Pierre Auger Observatory has been designed to investigate the origin and the nature of Ultra High Energy Cosmic Rays using a hybrid detection technique. It is located on a plateau in the Province of Mendoza, Argentina, and consists of a surface array of about 3000 km2 overlooked by 24 air fluorescence telescopes grouped in 4 sites which together provide a powerful instrument for air shower reconstruction. The southern of the Auger Observatory has been completed in June 2008 and it is taking data smoothly since 2004. A review of selected results is presented with the emphasis given to the measurement of energy spectrum,
chemical composition and search for photon and neutrinos as primary particles
Exploring the Universe with Ultra High Energy Cosmic Rays
Full text linkUltra High Energy Cosmic Rays (UHECR) are messengers of the most powerful astrophysical
sources in the universe and they offer the unique chance of investigating particle interactions
over an energy range well beyond the one covered by present ground-based particle accelerators.
Despite several progresses have been made in the last decade, the understanding of the nature of
UHECR and of their origin remains an open science case. A review of selected results from the
largest UHECR experiments, namely The Pierre Auger Observatory and the Telescope Array, is
presented with the emphasis given to the measurements of energy spectrum, arrival directions,
chemical composition, and the search for photons and neutrinos as primary particles. Connection
to hadronic physics and open issues will also be discussed along with the perspectives for near
future measurements
RESULTS FROM THE PIERRE AUGER OBSERVATORY
Full text linkThe Pierre Auger Observatory has been designed to investigate the origin and the nature of Ultra High Energy Cosmic Rays using a hybrid detection technique. It is located on a plateau in the Province of Mendoza, Argentina, and consists of a surface array of about 3000 km2 overlooked by 24 air fluorescence telescopes grouped in 4 sites which together provide a powerful instrument for air shower reconstruction. The Southern site of the Auger Observatory has been completed in June 2008 and is taking data smoothly since 2004. A review of selected results is presented with the emphasis given to the measurement of energy spectrum, chemical composition and search for photons and neutrinos as primary particles
Search for primary photons and neutrinos in the ultra-high energy cosmic rays with the Pierre Auger Observatory
No full textAlong with primary protons and nuclei most of the scenarios of the origin of cosmic rays predict fluxes of photons and neutrinos at the highest energies. Thanks to the huge collection area and the hybrid design, combining ground array and fluorescence detection techniques, the Pierre Auger Observatory is a unique tool to search for primary photons and neutrinos in ultra-high energy cosmic rays. Implications of these searches extend from astrophysics to fundamental and particle physics. Current results and future perspectives are reported
Results from the Pierre Auger Observatory
No full textThe Pierre Auger Observatory has been designed to investigate the origin and the nature of Ultra High Energy Cosmic Rays using a hybrid detection technique. It is located on a plateau in the Province of Mendoza, Argentina,
and consists of a surface array of about 3000 km^2 overlooked by 24
air fluorescence telescopes grouped in 4 sites, which together provide a
powerful instrument for air shower reconstruction.
The combination of information from the surface array, measuring the
lateral distributions of secondary particles at the ground, and the
fluorescence telescopes, observing the longitudinal profile, enhances
the reconstruction capability with respect to the individual detector components.
The Observatory was completed in 2008 and it is taking data smoothly since 2004. Moreover, detector enhancements are being constructed to extend the sensitivity of the Observatory towards the lower energies.
A review of selected results is presented with the emphasis given to the measurement of energy spectrum, arrival directions, chemical composition and search for photons and neutrinos as primary particles
Measurement of the UHECR energy spectrum from hybrid data of the Pierre Auger Observatory
No full textMore than two years of fluorescence detector data collected in coincidence with at least one station of the surface detector array (“hybrid data”) are used to measure the flux and energy spectrum of cosmic rays above about 10**18 eV. The hybrid measurement extends towards lower energies the spectrum measured with the surface detector data only, and provides a cross-check with an independent data set. The determination of the fluorescence detector aperture and of its live-time, which is the major aspect of this measurement, is illustrated in detail. Our current estimate of the corresponding systematic uncertainties are given
Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory
Full text linkData from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius A. Also the events detected simultaneously by the surface and fluorescence detectors (the ‘hybrid’ data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.http://www.elsevier.com/wps/find/journaldescription.cws_home/523319/description#descriptio
Results from the Pierre Auger Observatory
No full texthe Pierre Auger Observatory has been designed to investigate the origin and the nature of Ultra High Energy Cosmic Rays using a hybrid detection technique. It islocated in the Province of Mendoza, Argentina, and consists of a surface array of about 3000 km2 overlooked by 27 air fluorescence telescopes grouped in four sites, which together provide a powerful instrument for air shower reconstruction. The combination of information from the surface array, measuring the lateral distributions of secondary particles at the ground, and the fluorescence telescopes, observing the longitudinal profile, enhances the reconstruction capability with respect to the individual detector components. Ultra High Energy Cosmic Rays offer also the unique chance of investigating particle interactions over an energy range well beyond the one covered by present and future ground-based particle accelerators. A review of selected results is presented with the emphasis given to the measurement of energy spectrum, arrival directions, chemical composition and the search for photons and neutrinos as primary particles
Atmospheric aerosol characterization using the central laser facility at the Pierre Auger Observatory
No full textThe Fluorescence Detector of the Pierre Auger Observatory uses the atmosphere as a huge calorimeter that needs continuous
monitoring to ensure unbiased physics results. The Central Laser Facility (CLF), a calibrated laser source located near the centre
of the Observatory, is used to measure the light attenuation due to aerosols, highly variable even on time scales of one hour. Two
independent, fully compatible procedures based on the analysis of CLF vertical events have been developed. Five years of hourly
aerosol characterization are provide
Missing energy estimate in the light of the muon discrepancy
Full text linkThe determination of the primary energy of extensive air showers using the fluorescence technique requires an estimation of the energy carried away by the particles that do not deposit all their energy in the atmosphere. This estimation is typically made using Monte Carlo simulations and thus depends on the model predictions for neutrino and muon production. In this contribution we describe a new method that could be used to obtain the missing energy directly from events measured simultaneously with the fluo- rescence and the surface detectors of the Pierre Auger Observatory, based on a toy model of the shower cascade. The method is applied to a synthetic sample of events to show its robustness and we discuss how the results could be used to make an estimation of the number of high energy muons in the cascade.Fil: Tueros, Matias Jorge. Universidad de Santiago de Compostela; España. Observatorio Pierre Auger; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: The Pierre Auger Collaboration. No especifíca;International Symposium on Future Directions in Ultra High Energy Cosmic Ray PhysicsGinebraSuizaConseil Européen pour la Recherche Nucléair
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