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 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 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 Ultra High Energy Cosmic Ray Flux Using Data of the Pierre Auger Observatory written by Ioana Codrina Maris and published by . This book was released on 2009 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 Mass Composition Studies of Ultra High Energy Cosmic Rays Through the Measurement of the Muon Production Depths at the Pierre Auger Observatory written by Laura Collica and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory studies Ultra High Energy Cosmic Rays (UHECRs) physics. The flux of UHECRs is very low (less than 1 particle/km2-year) and their properties must be inferred from the measurements of the secondary particles that the cosmic ray primary produces in the atmosphere. These particles cascades are called Extensive Air Showers (EAS) and can be studied at ground by deploying detectors covering large areas. The EAS physics is complex, and the properties of secondary particles depend strongly on the first interaction, which takes place at an energy beyond the ones reached at accelerators. As a consequence, the analysis of UHECRs is subject to large uncertainties and hence many of their properties, in particular their composition, are still unclear. Two complementary techniques are used at Auger to detect EAS initiated by UHECRs: a 3000 km2 surface detector (SD) array of water Cherenkov tanks which samples particles at ground level and fluorescence detectors (FD) which collect the ultraviolet light emitted by the de-excitation of nitrogen nuclei in the atmosphere, and can operate only in clear, moonless nights. The main goal of this thesis is the measurement of UHECR mass composition using data from the SD of the Pierre Auger Observatory. Measuring the cosmic ray composition at the highe-st energies is of fundamental importance for particle physics and astrophysics. Indeed, it allows to explore the hadronic interactions at ultra-high energies, and to discriminate between different scenarios of origin and propagation of cosmic rays.
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:
Download or read book Upper Limits on the Ultra high Energy Cosmic Ray Flux from Unresolved Sources written by Ross E. Burton and published by . This book was released on 2012 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory is the world's largest ultra-high energy cosmic ray detector. Its goals include answering basic questions about the origins and composition of cosmic rays at the highest energies. We outline the scientific motivation for constructing such an observatory and we highlight some of the significant results produced so far by this world-class instrument. We present the results of our own contributions toward calibrating the timing characteristics of the instrument followed by two alternative techniques for analyzing cosmic ray arrival direction data. The first technique is based on a Bayesian statistical framework and is presented as a solution to some of the difficulties in applying a standard analysis to identify anisotropy in the cosmic ray flux. The second analysis we present is based on a Markov Chain Monte Carlo method for identifying sources of cosmic rays in our arrival direction data. We are able to use our method to set an upper limit of 0.15 per square km per year on the flux from any potential sources producing ultra-high energy cosmic rays with energy E{u2265}3 EeV. We conclude with a proposal for enhancing the already successful observatory with an array of non-imaging Cherenkov detectors. According to our simulation work, such an array could serve as both an independent measure of the cosmic ray energy and, if the array is dense enough, it could also provide insight into the composition of ultra-high energy cosmic rays on an event by event basis.
Download or read book The Ultra High Energy Cosmic Ray Flux from the Southern Pierre Auger Observatory Data written by Nicolás G. Busca and published by . This book was released on 2006 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measuring the Speed of Ultra high Energy Cosmic Ray Air Showers as an Exotic Particle Signature at the Southern Pierre Auger Observatory written by Kathleen E. Gesterling and published by . This book was released on 2009 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 The Cosmic Ray Spectrum at the Highest Energy written by Alessio Gorgi and published by . This book was released on 2009 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory aims to study the ultra high energy cosmic rays with energies above 1 EeV. To get an accurate measurement of the characteristic of the extensive air showers that the cosmic rays generate in the atmosphere, the Observatory uses a hybrid technique. In this work we have studied the detector performance, including trigger and hardware efficiencies. We have optimized the event selection and estimated the efficiency of the detector acceptance. Uncertainties for event reconstruction were evaluated and propagated to the measured energy spectrum. We have shown that some stations that are not courrently considered part of the event can be included in the event selection procedure. We have studied the effect of loosing the signal of one of the three photomultipliers due to some failure, or the effect of the saturation of the ADC channels or of the photomultiplier to the reconstruction accuracy. The reconstruction uncertainty was also studied in case of ``normal'' events using a method based on fluctuations, to cross-check the results obtained using the fit accuracies. An evaluation of the trigger efficiency was also performed in case one of the three photomultipliers is missing. We have shown that the problems related to the instrumental apparatus only reduce the efficiency where it is not already 100\% and in most of the cases the reconstruction uncertainties are only slightly affected. Furthermore this work gives the first indication that the reconstruction uncertainties of the surface detector data do not change the index of the power law of the measured cosmic rays spectrum.
Download or read book A Study of Ultra high Energy Cosmic Ray Composition and Hadronic Interactions with Data from the Pierre Auger Observatory written by Florin Ioniță and published by . This book was released on 2011 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-high energy cosmic rays are particles of enormous energy -- greater than 1018 eV -- reaching Earth from still mysterious sources. In this thesis, we analyze data from the Pierre Auger Observatory, a giant cosmic ray detector located in Argentina, to derive information on the mass of ultra-high energy cosmic rays and on their hadronic interaction properties. The data show a change of cosmic ray mass composition as a function of energy. We perform a measurement of the proton-air inelastic cross section, yielding sinelp-air =501+24-23 stat+30 -35syst +30-32 composition mb, at an equivalent energy of 57 TeV in the center of mass of a proton-proton collision -- a range yet inaccessible to particle accelerators. The measured cross section is in good agreement with predictions from hadronic interaction models.
Download or read book Mass Composition of Ultra high Energy Cosmic Rays written by Livingstone Ochilo and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A complete method to obtain the energy spectrum of inclined cosnic rays detected with the Pierre Auger Observatory written by and published by Univ Santiago de Compostela. This book was released on with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
