0000000000173377
AUTHOR
Marco Iarlori
Measurement of the energy spectrum of cosmic rays above 10^18 eV using the Pierre Auger Observatory
We report a measurement of the flux of cosmic rays with unprecedented precision and Statistics using the Pierre Auger Observatory Based on fluorescence observations in coincidence with at least one Surface detector we derive a spectrum for energies above 10(18) eV We also update the previously published energy spectrum obtained with the surface detector array The two spectra are combined addressing the systematic uncertainties and, in particular. the influence of the energy resolution on the spectral shape The spectrum can be described by a broken power law E-gamma with index gamma = 3 3 below the ankle which is measured at log(10)(E-ankle/eV) = 18 6 Above the ankle the spectrum is describe…
EARLINET observations of the 14-22-may long-range dust transport event during SAMUM 2006: validation of results from dust transport modelling
We observed a long-range transport event of mineral dust from North Africa to South Europe during the Saharan Mineral Dust Experiment (SAMUM) 2006. Geometrical and optical properties of that dust plume were determined with Sun photometer of the Aerosol Robotic Network (AERONET) and Raman lidar near the North African source region, and with Sun photometers of AERONET and lidars of the European Aerosol Research Lidar Network (EARLINET) in the far field in Europe. Extinction-to-backscatter ratios of the dust plume over Morocco and Southern Europe do not differ. Ångstr¨om exponents increase with distance from Morocco. We simulated the transport, and geometrical and optical properties of the dus…
ARCADE: Description of the project and setup of the Lidar/AMT system
The ARCADE (Atmospheric Research for Climate and Astroparticle DEtection) project is a 3 years project funded by MIUR, that aims to study the aerosol attenuation of UV light in atmosphere using multiple instruments and techniques, as those commonly used in the cosmic rays community: elastic Lidar, Raman Lidar, side-scattering measurements using a distant laser source. All measurements will be acquired on the same air mass at the same time, in a semi-desertic site near Lamar, Colorado (U.S.). For each instrument, multiple analysis techniques will be tested: the target is a better comprehension of the systematics and limits of applicability of each method. The system is composed by a Lidar (e…
Limit on the diffuse flux of ultrahigh energy tau neutrinos with the surface detector of the Pierre Auger Observatory
Data collected at the Pierre Auger Observatory are used to establish an upper limit on the diffuse flux of tau neutrinos in the cosmic radiation. Earth-skimming ντ may interact in the Earth's crust and produce a τ lepton by means of charged-current interactions. The τ lepton may emerge from the Earth and decay in the atmosphere to produce a nearly horizontal shower with a typical signature, a persistent electromagnetic component even at very large atmospheric depths. The search procedure to select events induced by τ decays against the background of normal showers induced by cosmic rays is described. The method used to compute the exposure for a detector continuously growing with time is de…
Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation
Full list of authors: Abdalla, H.; Abe, H.; Acero, F.; Acharyya, A.; Adam, R.; Agudo, I; Aguirre-Santaella, A.; Alfaro, R.; Alfaro, J.; Alispach, C.; Aloisio, R.; Batista, R. Alves; Amati, L.; Amato, E.; Ambrosi, G.; Anguner, E. O.; Araudo, A.; Armstrong, T.; Arqueros, F.; Arrabito, L.; Asano, K.; Ascasibar, Y.; Ashley, M.; Backes, M.; Balazs, C.; Balbo, M.; Balmaverde, B.; Baquero Larriva, A.; Martins, V. Barbosa; Barkov, M.; Baroncelli, L.; de Almeida, U. Barres; Barrio, J. A.; Batista, P-, I; Becerra Gonzalez, J.; Becherini, Y.; Beck, G.; Tjus, J. Becker; Belmont, R.; Benbow, W.; Bernardini, E.; Berti, A.; Berton, M.; Bertucci, B.; Beshley, V; Bi, B.; Biasuzzi, B.; Biland, A.; Bissaldi, …
The Fluorescence Detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detecto…
THE ARCADE PROJECT
The Atmospheric Research for Climate and Astroparticle Detection (ARCADE) project aims to a better comprehension of the limits of applicability, systematics and possible enhancements of the typical techniques used for the measurement of the aerosol attenuation profiles of UV light in cosmic rays and gamma rays experiments. Aerosols are indeed the most variable component in the atmosphere on a short time scale, and experiments based on the detection of the UV light in atmosphere need a continuous monitoring of the aerosol stratification to obtain a reliable evaluation of the properties of the primary particles. The ARCADE project is measuring the aerosol attenuation of UV light due to aeroso…
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density (ρ ∝ P/T), affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ∼ 10% seasonal modulation and ∼ 2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of P and ρ. The former affects the longitudinal development of air showers while the latter influences the Molière radius and hence the lateral distribution of the shower particles. The model is val…
Erratum to "Atmospheric effects on extensive air showers observed with the surface detector of the Pierre Auger observatory"[Astroparticle Physics 32(2) (2009), 89-99]
The Pierre Auger Collaboration... K.B. Barber... J.A. Bellido... R.W. Clay... B.R. Dawson... V.C. Holmes... J. Sorokin... P. Wahrlich... B.J. Whelan... M.G. Winnick... et al.
Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory
The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth’s crust. Tau leptons from ντ charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of ντ at EeV energies. Assuming an E−2ν differential energy spectrum the limit set at 90% C.L. is E2νdNντdEν<1.3×10−7 GeV cm−2 s−1 sr−1 in the energy range 2×1017 eV<E<2×1019 eV.
Trigger and aperture of the surface detector array of the Pierre Auger Observatory
The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive airshowers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidates howers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above 3 x 1018 eV, for all zenith angles between 03 and 603, independently of the position of the impact point and of the mass of the primary particl…