Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ 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 $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.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

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

The Large High Altitude Air Shower Observatory (LHAASO) Science White Paper

The Large High Altitude Air Shower Observatory (LHAASO) project is a new generation multi-component instrument, to be built at 4410 meters of altitude in the Sichuan province of China, with the aim to study with unprecedented sensitivity the spec trum, the composition and the anisotropy of cosmic rays in the energy range between 10$^{12}$ and 10$^{18}$ eV, as well as to act simultaneously as a wide aperture (one stereoradiant), continuously-operated gamma ray telescope in the energy range between 10$^{11}$ and $10^{15}$ eV. The experiment will be able of continuously surveying the TeV sky for steady and transient sources from 100 GeV to 1 PeV, t hus opening for the first time the 100-1000 TeV range to the direct observations of the high energy cosmic ray sources. In addition, the different observables (electronic, muonic and Cherenkov/fluorescence components) that will be measured in LHAASO will allow to investigate origin, acceleration and propagation of the radiation through a measurement of energy spec trum, elemental composition and anisotropy with unprecedented resolution. The remarkable sensitivity of LHAASO in cosmic rays physics and gamma astronomy would play a key-role in the comprehensive general program to explore the High Energy Universe. LHAASO will allow important studies of fundamental physics (such as indirect dark matter search, Lorentz invariance violation, quantum gravity) and solar and heliospheric physics. In this document we introduce the concept of LHAASO and the main science goals, providing an overview of the project.Comment: This document is a collaborative effort, 185 pages, 110 figure

Study of the discriminatory potential of primary particles initiating large air showers with arrays of ground detectors : analysis of ultra high-energy cosmic rays detected at the Pierre Auger observatory, Performance of very-high-energy gamma rays detection at the future LHAASO observatory

Depuis plus d’un siècle, les rayons cosmiques d’ultra-haute énergie (RCUHE), ayant une énergie supérieure à 1018 eV, continuent d’entretenir le mystère : Quelle est leur composition ? D’où viennent-ils ? Comment atteignent-ils de telles énergies ? Ces particules chargées, suffisamment énergétiques pour atteindre la Terre, forment des gerbes de particules secondaires via leurs interactions avec l’atmosphère dont le développement est caractéristique de la nature de la particule primaire. L’observatoire Pierre Auger, avec sa structure hybride et son gigantesque réseau de détecteurs peuvent apporter des réponses. L’étude de la composition des RCUHEs a été étudiée avec le réseau de surface de l’observatoire Pierre Auger. Cette dernière est cruciale à la fois pour comprendre les interactions hadroniques, qui constituent le développement des gerbes, et pour identifier leurs sources. Cela peut également aider à comprendre l’origine de la coupure spectrale aux plus hautes énergies : s’agit-il de la coupure GZK ou à l’extinction des sources. Toutes ces raisons motivent la première partie de la thèse, à savoir la mise en place d’une méthode permettant d’extraire la composante muonique des gerbes atmosphériques et d’en déduire la composition. Les résultats de cette méthode montrent une dépendance de la composition avec la distance à l’axe de la gerbe, qui pourrait aider à améliorer les modèles hadroniques. Dans les conditions actuelles du réseau de surface, l’identification de la composante muonique présente des limites.La seconde partie est consacrée au nouvel observatoire en Chine, LHAASO. Ce projet s’intéresse à l’étude des gammas supérieurs à 30 TeV, qui signeraient l’accélération de proton dans la galaxie, donnant ainsi des informations indirectes sur les rayons cosmiques. D’autre part, l’observatoire vise à étudier les rayons cosmiques entre 10 TeV et 1 EeV, région où le spectre en énergie présente une rupture. Cette région nécessite de pouvoir discriminer les gammas des rayons cosmiques. A ce titre, l’un des détecteurs de LHAASO, le KM2A, a été simulé et son pouvoir de discrimination gamma/hadron évalué.During the past century, ultra-high-energy cosmic rays (UHECR), those with an energy larger than 1018 eV, remain as a mystery: What are cosmic rays? Where do they come from? How do they attain their huge energy? When these charged particles strike the earth's atmosphere, they dissipate their energy by generating a shower of secondary particles whose development is significantly different depending on the nature of the primaries. The Pierre Auger observatory, with its hybrid structure and huge size network of ground detectors, can shed some light into these questions.The study of the composition of UHECR was performed with the Pierre Auger apparatus. This is crucial both to understand the hadronic interactions, which govern the evolution of showers, and to identify their sources. It can help to understand the origin of the energy spectrum cut-off: is it the GZK cut-off or the exhaustion of sources? These reasons motivate the first part of this thesis: the development of a method to extract the muonic component of air showers and deduce the implications on the composition of UHECR at the Pierre Auger observatory. The results of this method show a dependence of the composition with the distance to the axis of the shower, which could help to improve the hadronic models. The determination of the muon component is limited by the surface detector setup.The second part is devoted to the new observatory in China, LHAASO. This project focuses on the study of gamma rays with an energy higher than 30 TeV, which probe the acceleration of protons in the galaxy, providing indirect information on cosmic rays. Moreover, the observatory studies cosmic rays between 10 TeV and 1 EeV, one of the regions where the energy spectrum presents a break. This region requires the ability to discriminate gamma rays and cosmic rays. For this reason, one of the detectors of LHAASO, the KM2A, was simulated and its power of discrimination gamma/hadron evaluated

Étude du pouvoir de discrimination des primaires initiant les grandes gerbes atmosphériques avec des réseaux de détecteurs au sol : analyse des rayons cosmiques de ultra haute énergie détectés à l’observatoire Pierre Auger, Estimation des performances pour la detection de gamma de très haute énergie du future observatoire LHAASO

During the past century, ultra-high-energy cosmic rays (UHECR), those with an energy larger than 1018 eV, remain as a mystery: What are cosmic rays? Where do they come from? How do they attain their huge energy? When these charged particles strike the earth's atmosphere, they dissipate their energy by generating a shower of secondary particles whose development is significantly different depending on the nature of the primaries. The Pierre Auger observatory, with its hybrid structure and huge size network of ground detectors, can shed some light into these questions.The study of the composition of UHECR was performed with the Pierre Auger apparatus. This is crucial both to understand the hadronic interactions, which govern the evolution of showers, and to identify their sources. It can help to understand the origin of the energy spectrum cut-off: is it the GZK cut-off or the exhaustion of sources? These reasons motivate the first part of this thesis: the development of a method to extract the muonic component of air showers and deduce the implications on the composition of UHECR at the Pierre Auger observatory. The results of this method show a dependence of the composition with the distance to the axis of the shower, which could help to improve the hadronic models. The determination of the muon component is limited by the surface detector setup.The second part is devoted to the new observatory in China, LHAASO. This project focuses on the study of gamma rays with an energy higher than 30 TeV, which probe the acceleration of protons in the galaxy, providing indirect information on cosmic rays. Moreover, the observatory studies cosmic rays between 10 TeV and 1 EeV, one of the regions where the energy spectrum presents a break. This region requires the ability to discriminate gamma rays and cosmic rays. For this reason, one of the detectors of LHAASO, the KM2A, was simulated and its power of discrimination gamma/hadron evaluated.Depuis plus d’un siècle, les rayons cosmiques d’ultra-haute énergie (RCUHE), ayant une énergie supérieure à 1018 eV, continuent d’entretenir le mystère : Quelle est leur composition ? D’où viennent-ils ? Comment atteignent-ils de telles énergies ? Ces particules chargées, suffisamment énergétiques pour atteindre la Terre, forment des gerbes de particules secondaires via leurs interactions avec l’atmosphère dont le développement est caractéristique de la nature de la particule primaire. L’observatoire Pierre Auger, avec sa structure hybride et son gigantesque réseau de détecteurs peuvent apporter des réponses. L’étude de la composition des RCUHEs a été étudiée avec le réseau de surface de l’observatoire Pierre Auger. Cette dernière est cruciale à la fois pour comprendre les interactions hadroniques, qui constituent le développement des gerbes, et pour identifier leurs sources. Cela peut également aider à comprendre l’origine de la coupure spectrale aux plus hautes énergies : s’agit-il de la coupure GZK ou à l’extinction des sources. Toutes ces raisons motivent la première partie de la thèse, à savoir la mise en place d’une méthode permettant d’extraire la composante muonique des gerbes atmosphériques et d’en déduire la composition. Les résultats de cette méthode montrent une dépendance de la composition avec la distance à l’axe de la gerbe, qui pourrait aider à améliorer les modèles hadroniques. Dans les conditions actuelles du réseau de surface, l’identification de la composante muonique présente des limites.La seconde partie est consacrée au nouvel observatoire en Chine, LHAASO. Ce projet s’intéresse à l’étude des gammas supérieurs à 30 TeV, qui signeraient l’accélération de proton dans la galaxie, donnant ainsi des informations indirectes sur les rayons cosmiques. D’autre part, l’observatoire vise à étudier les rayons cosmiques entre 10 TeV et 1 EeV, région où le spectre en énergie présente une rupture. Cette région nécessite de pouvoir discriminer les gammas des rayons cosmiques. A ce titre, l’un des détecteurs de LHAASO, le KM2A, a été simulé et son pouvoir de discrimination gamma/hadron évalué

Käytännön kosteikkosuunnittelu

Maatalouden vesiensuojelua edistetään monin tavoin. Ravinteita ja eroosioainesta sisältäviä valumavesiä pyritään puhdistamaan erilaisissa kosteikoissa. Tämä opas on kirjoitettu avuksi pienimuotoisten kosteikkojen perustamiseen. Oppaassa esitetään käytännönläheisesti kosteikon toteuttamisen eri vaiheet paikan valinnasta suunnitteluun ja rakentamiseen. Vuonna 2010 julkaistun painoksen tiedot on saatettu ajantasalle. Julkaisu on toteutettu osana Tehoa maatalouden vesiensuojeluun (TEHO) -hanketta ja päivitetty TEHO Plus -hankkeen toimesta. Oppaan toivotaan lisäävän kiinnostusta kosteikkojen suunnitteluun ja edelleen niiden rakentamiseen

Chapter 4 Cosmic-Ray Physics *

Abstract In the first part of this Chapter the present state of knowledge from the observations of cosmic rays between 1013 and 1020 eV is summarized. This is not intended to be a complete review, but rather a broad overview of the relevant processes involving cosmic rays, including the astrophysical environments in which they take place. This overview mainly concerns experimental results and phenomenological aspects of their interpretation, therefore experiments’ description is not given but references to the vast bibliography are provided in the text. Some attempt is made to address the most popular explanations offered by theoretical models. The second part is devoted to the description of the LHAASO performance and of its capability to provide a response to several open questions, still unanswered, concerning cosmic rays above 1013 eV, highlighting which major steps forward in this field could be taken from LHAASO observations. </jats:p