Download or read book Measurement of the Cosmic Ray Spectrum Above 4 u00D7 1018 EV Using Inclined Events Detected with the Pierre Auger Observatory written by and published by . This book was released on 2015 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° 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 5.3×1018 eV, the à̀nkle'', the flux can be described by a power law E–? with index ?=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0–1.2 (sys))×1019 eV.
Download or read book Measurement of the Cosmic Ray Spectrum Above 4 1018 EV Using Inclined Events Detected with the Pierre Auger Observatory written by and published by . This book was released on 2015 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° 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 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E-[gamma] with index [gamma]=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0-1.2 (sys))×1019 eV.
Download or read book Measurement of the Energy Spectrum of Cosmic Rays Above 3 X 1017 EV Using the Infill Array of the Pierre Auger Observatory written by Rivera Bretel Hugo Marcelo and published by . This book was released on 2013 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory, in Argentina, combines a 3000 $\mathrm{km^2}$ surface array of water Cherenkov detectors with fluorescence telescopes to measure extensive air showers initiated by ultra-high energy cosmic rays. This "hybrid" observatory (in operation since 2004, and completed in 2008) is fully efficient for cosmic rays energies above $10^{18}$ eV, that is, from just below the "ankle" of the energy spectrum up to the highest energies.After the completion of the main observatory, the Auger collaboration has started to deploy new instruments to extend the energy range down to about 0.1 EeV. The planned extensions include two infill surface arrays with 750 and 433 m spacing, with muon detection capabilities, and three additional fluorescence telescopes with a more elevated field of view. The 750 m infill array (covering about 24 $\mathrm{km^2}$) and the new telescopes are now operational. Their aim is the measurement of cosmic rays from below the second knee of the spectrum up to the ankle, where data from the extensions overlap those from the main observatory. The study of the evolutior of the spectrum through the second knee and the ankle, together with the primary mass composition, are crucial to the understanding of the transition from a galactic cosmic ray origin to an extragalactic one.This thesis makes use of data from the 750 m infill array: the objective is the measurement of the cosmic ray energy spectrum in the energy region above $3 \times 10^{17}$ eV, where the array is fully efficient. To get to the energy spectrum, several steps are needed, from the reconstruction of events, through the precise determination of the exposure of the array, up to the determination of the primary energy. The thesis deals with these aspects, before reaching the final result.The first chapter gives a general introduction to cosmic ray physics and detectors. It also summarizes experimental results above the first knee of the spectrum with particular emphasis on those obtained above $10^{17}$ eV. The next two chapters describe the Pierre Auger Observatory and the infill array, respectively. In chapter 2, the main Auger results are summarized too, after a schematic description of th different components of the observatory. Chapter 3 sets the stage for the following chapters. It presents a more detailed description of the characteristics of the infill array, in particular the trigger definitions, event selection and reconstruction. In chapter 4 the performance of the reconstruction of the lateral distribution of observed showers is studied in detail. This is particularly important for the energy spectrum, since the signal at a fixed distance from the shower axis is used as the energy estimator of the event. This signal is estimated by means c the measured lateral distribution of the shower. Chapter 5 presents a comparison between the event reconstruction of the infill and main arrays. Using the set of showers detected by both instruments, the derived geometry and energy estimation are compared, showing a good agreement. In chapter 6, the energy threshold of the array, and hence the set of events to be used, is defined. The methods to obtain the exposure of the array are discussed, as well as related systematic uncertainties. Finally, in chapter 7, the technique to derive the primary energy for each detected shower is presented. The derived energy spectrum is discussed, and the flux is shown to be consistent with that measured by other instruments in the overlapping energy regions.
Download or read book Measurement of the Cosmic Ray Flux Above 100 PeV at the Pierre Auger Observatory written by Alan Coleman and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmic rays are particles and nuclei that arrive at Earth and act as messengers, informing us of the nature of celestial objects and events throughout the universe. Some of the highest energy events, with over a Joule of energy, are more energetic than what can be made on Earth in modern particle accelerators. In the ultra-highenergy range > 100 PeV, the arrival rate is low enough (1 per km 2 per year, or less) that there are still many outstanding questions concerning their origin and what types of particles they are. Further, their rarity presents an experimental challenge as direct detection of cosmic rays above this energy would require decades to centuries of data collection. Instead, the particles cascades created by ultra-high energy cosmic rays interacting with air molecules high in the atmosphere, called air showers, can be detected using observatories that cover 10-1000 km^2 . The Pierre Auger Observatory includes a number of methods to detect air showers and covers over 3000 km^2 in the Mendoza Province of Argentina. The Observatory includes a hybrid design by which air showers can be detected by fluorescence detectors while they are developing in the air as well as by an array of surface detectors on the ground. This thesis includes an extensive update to the reconstruction methods used to estimate the trajectory and energy of a cosmic ray using a hexagonal array of water Cherenkov detectors with 750 m spacing. The update was motivated by the inclusion of a new set of particle triggers that were installed in the local stationsthat make up the array. These triggers were designed to be insensitive to muons which make up the primary background for individual stations. Thus, they increase the sensitivity of the array to lower energy parts of air showers and lower energy showers in general.A major component of this work was the characterization of the arrays abilities to detect and sample air showers with the new trigger algorithms. On the level of individual stations, the triggering efficiency and distribution of signals was studied. On the array-level, the efficiency with which the 750 m array detects showers was also calculated for two sets of cosmic ray masses using a dedicated set of air shower simulations based on hadronic interaction models.The second component of this thesis was an improvement of Augers model of air shower development. Due to a lack of understanding of hadronic cross sections in the ultra-high energy regime, empirical models are used to characterize the temporal and spatial distribution of particles within the cascade. The distributionof signal as a function of distance from an air showers central axis was updated, benefiting from the 30% more sampling of the shower front by new-triggered stations. This model is particularly important as it is used to find the expected signal at a fixed reference distance from the axis to estimate the showers size, a quantity highly correlated to energy. These size estimations were then corrected for a number of systematic biases to produce a more precise energy estimator. Finally, the energy estimators were cross-calibrated with the nearly calorimetric energy measurements made by the fluorescence detectors. This allowed for the surface detector to directly estimate energies accurate to within E/E = 14-15%.Motivated by the parameter space where the array can detect showers with full efficiency, two semi-joint data sets were chosen which included energies and zenith angles (E > 10^17 eV, 40 ) and (E 10^17.3 eV,
Download or read book Measurement of the Cosmic Ray Energy Spectrum Using Hybrid Events of the Pierre Auger Observatory written by and published by . This book was released on 2012 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Cosmic Ray Spectrum with the Pierre Auger Observatory written by and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Ultra High Energy Cosmic Ray Flux from Data of Very Inclined Showers at the Pierre Auger Observatory written by Hans Peter Dembinski and published by . This book was released on 2009 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book First estimate of the primary cosmic ray energy spectrum above 3 EeV from the Pierre Auger Observatory written by Paul Sommers and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of air showers are accumulating at an increasing rate while construction proceeds at the Pierre Auger Observatory. Although the southern site is only half complete, the cumulative exposure is already similar to those achieved by the largest forerunner experiments. A measurement of the cosmic ray energy spectrum in the southern sky is reported here. The methods are simple and robust, exploiting the combination of fluorescence detector (FD) and surface detector (SD). The methods do not rely on detailed numerical simulation or any assumption about the chemical composition.
Download or read book Measurement of the Flux of Ultra High Energy Cosmic Rays Using Very Inclined Extensive Air Showers Measured at the Pierre Auger Observatory written by Talianna Schmidt and published by . This book was released on 2010 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Features of the Energy Spectrum of Cosmic Rays Above 2 5 times 10 18 EV Using the Pierre Auger Observatory written by Alexander Aab and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Scale Distribution of Arrival Directions of Cosmic Rays Detected Above 10 EV at the Pierre Auger Observatory written by and published by . This book was released on 2012 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Patterns by Combining Cosmic ray Energy and Arrival Directions at the Pierre Auger Observatory written by and published by . This book was released on 2015 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with $E \ge 6 \times 10^$ eV by analyzing cosmic rays with energies above $E \ge 5 \times 10^$ eV arriving within an angular separation of approximately 15$^{\circ }$ . We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.
Download or read book Measurement of the Energy Spectrum of Ultra high Energy Cosmic Rays Using Hybrid Data of the Pierre Auger Observatory written by Fabian Schüssler and published by . This book was released on 2009 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cosmic Ray Air Shower Measurement from Space written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-17 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A feasibility study has been initiated to observe from space the highest energy cosmic rays above 1021 eV. A satellite observatory concept, the Maximum-energy Auger (Air)-Shower Satellite (MASS), is recently renamed as the Orbital Wide-angle Collector (OWL) by taking its unique feature of using a very wide field-of-view (FOV) optics. A huge array of imaging devices (about 10(exp 6) pixels) is required to detect and record fluorescent light profiles of cosmic ray cascades in the atmosphere. The FOV of MASS could extend to as large as about 60 in. diameter, which views (500 - 1000 km) of earth's surface and more than 300 - 1000 cosmic ray events per year could be observed above 1020 eV. From far above the atmosphere, the MASS/OWL satellite should be capable of observing events at all angles including near horizontal tracks, and would have considerable aperture for high energy photon and neutrino observation. With a large aperture and the spatial and temporal resolution, MASS could determine the energy spectrum, the mass composition, and arrival anisotropy of cosmic rays from 1020 eV to 1022 eV; a region hitherto not explored by ground-based detectors such as the Fly's Eye and air-shower arrays. MASS/OWL's ability to identify cosmic neutrinos and gamma rays may help providing evidence for the theory which attributes the above cut-off cosmic ray flux to the decay of topological defects. Very wide FOV optics system of MASS/OWL with a large array of imaging devices is applicable to observe other atmospheric phenomena including upper atmospheric lightning. The wide FOV MASS optics being developed can also improve ground-based gamma-ray observatories by allowing simultaneous observation of many gamma ray sources located at different constellations. Takahashi, Yoshiyuki Marshall Space Flight Center NASA-CR-204041, NAS 1.26:204041 NAS8-38609; NCC8-65...
Download or read book An Upper Limit to the Photon Fraction in Cosmic Rays Above 10 19 eV from the Pierre Auger Observatory written by and published by . This book was released on 2006 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies above 1019 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger surface detectors for a subset of the event sample, support the conclusion that a photon origin of the observed events is not favored.
Download or read book Measurement of the Cosmic Ray Composition with Air Showers Detected by the AMIGA Extension at the Pierre Auger Observatory written by Sarah Nicola Müller and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of the Highest Energy Cosmic Ray Air Showers with the Pierre Auger Observatory Hybrid Dectector written by Bei Cai and published by . This book was released on 2006 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
