104 research outputs found
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Multiple Scenario Generation of Subsurface Models:Consistent Integration of Information from Geophysical and Geological Data throuh Combination of Probabilistic Inverse Problem Theory and Geostatistics
Neutrinos with energies above 1017 eV are detectable with the Surface Detector Array of the Pierre Auger Observatory. The identification is efficiently performed for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for Earth-skimming \u3c4 neutrinos with nearly tangential trajectories relative to the Earth. No neutrino candidates were found in 3c 14.7 years of data taken up to 31 August 2018. This leads to restrictive upper bounds on their flux. The 90% C.L. single-flavor limit to the diffuse flux of ultra-high-energy neutrinos with an E\u3bd-2 spectrum in the energy range 1.0
7 1017 eV -2.5
7 1019 eV is E2 dN\u3bd/dE\u3bd < 4.4
7 10-9 GeV cm-2 s-1 sr-1, placing strong constraints on several models of neutrino production at EeV energies and on the properties of the sources of ultra-high-energy cosmic rays
New electronics for the surface detectors of the Pierre Auger Observatory
International audienceThe surface detector array of the Pierre Auger Observatory consists of 1660water-Cherenkov detectors that sample at the ground the charged particles andphotons of air showers initiated by energetic cosmic rays. Each detector recordsdata locally with timing obtained from Global Positioning System (GPS) units andpower from solar panels and batteries. In the framework of the upgrade of theAuger Observatory, AugerPrime, new electronics has been designed for the surfacedetectors. The electronics upgrade includes better timing with up-to-date GPSreceivers, higher sampling frequency, increased dynamic range, increasedprocessing capability, and better calibration and monitoring systems. It willalso process the data of the AugerPrime scintillator detectors. In this paper,the design of the new electronics will be presented and its performance will bediscussed in light of results from test measurements and from the engineeringarray data analysis
Etude des rayons cosmiques ultra-énergétiques avec l'observatoire Pierre Auger (de l'acceptance du détecteur à la nature des particules primaires et aux mesures d'anisotropies)
L'Observatoire Pierre Auger, actuellement en cours de construction en Argentine, étudie les rayons cosmiques dont l'énergie est supérieure à quelques EeV. L'expérience combine deux méthodes de détection des gerbes atmosphériques complémentaires: la mesure de la lumière de fluorescence et l'échantillonnage du profil latéral grâce à un réseau de détecteurs répartis au sol sur une surface d'environ 3000 kilomètres carrés. Les méthodes nécessaires au calcul de l'acceptance, dont la connaissance est cruciale pour établir le spectre d'énergie, ont été développées au cours du travail de thèse, et ont permis de déterminer de manière simple et robuste la surface effective de détection du réseau de surface de l'Observatoire Pierre Auger. L'efficacité de détection dépendant de la nature des rayons cosmiques, il est possible de caractériser leur composition grâce aux données du réseau de surface. Le calcul du spectre d'énergie des rayons cosmiques a été mené, en utilisant plusieurs méthodes pour estimer l'énergie des événements détectés. L'utilisation combinée des détecteurs de fluorescence avec le réseau de surface permet d'établir un étalonnage en énergie pratiquement indépendant des modèles d'interactions hadroniques. L'étude des anisotropies des directions d'arrivées des rayons cosmiques permet d'obtenir des informations précieuses sur leur origine et leur transport depuis leurs sources. Une nouvelle méthode d'analyse simple et efficace a été développée pour estimer les paramètres d'une anisotropie (dipôle et quadripôle) sous-jacente dans les données. Cette méthode est appliquée aux premières données de l'Observatoire Pierre Auger.The Pierre Auger Observatory, still under construction in Argentina, is designed to study the cosmic rays with energies above a few EeV. The experiment combines two complementary techniques: the fluorescence light detection and the sampling of the shower with an array of detectors at ground, covering a surface of 3000 square kilometers. The calculation of the acceptance of the detector, which is of utmost importance to establish the energy spectrum, has been achieved. The method of computation of the acceptance is simple and reliable. The detection efficiency depends on the nature of primary cosmic rays, allowing to study the cosmic rays composition with the surface detector. The calculation of the cosmic rays energy spectrum has been performed, using different methods to estimate the energy of the events. A cross calibration between the fluorescence and the surface detector provides an estimation of the energy almost independent of hadronic interaction models. The study of large scale anisotropies in the cosmic rays angular distribution provides useful informations about the cosmic rays sources and the conditions of propagation. A new analysis method is presented, allowing to estimate the parameters of an underlying dipolar and quadripolar anisotropy in the data. The method is applied to a preliminary Auger data set.STRASBOURG-Bib.Central Recherche (674822133) / SudocORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF
- …