Download or read book Anisotropy and Chemical Composition of Ultra high Energy Cosmic Rays Using Arrival Directions Measured by the Pierre Auger Observatory written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E> E{sub th} = 5.5 x 1019 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E> E{sub th} are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above E{sub th}/Z (for illustrative values of Z = 6,13,26). If the anisotropies above E{sub th} are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.
Download or read book Habitability of the Universe before Earth written by and published by Academic Press. This book was released on 2017-12-11 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Habitability of the Universe before Earth: Astrobiology: Exploring Life on Earth and Beyond (series) examines the times and places—before life existed on Earth—that might have provided suitable environments for life to occur, addressing the question: Is life on Earth de novo, or derived from previous life? The universe changed considerably during the vast epoch between the Big Bang 13.8 billion years ago and the first evidence of life on Earth 4.3 billion years ago, providing significant time and space to contemplate where, when and under what circumstances life might have arisen. No other book covers this cosmic time period from the point of view of its potential for life. The series covers a broad range of topics encompassing laboratory and field research into the origins and evolution of life on Earth, life in extreme environments and the search for habitable environments in our solar system and beyond, including exoplanets, exomoons and astronomical biosignatures. - Provides multiple hypotheses on the origin of life and distribution of living organisms in space - Explores the diversity of physical environments that may support the origin and evolution of life - Integrates contemporary views in biology and cosmology, and provides reasons that life is far more mobile in space than most people expect - Includes access to a companion web site featuring supplementary information such as animated computer simulations
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 Large Area Networked Detectors For Particle Astrophysics written by Pierre Sokolsky and published by World Scientific. This book was released on 2022-09-09 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: The universe is pervaded by particles with extreme energies, millions of times greater than we can produce on Earth. They have been a mystery for over a century. Now, current and future experiments in particle astrophysics are leading us to answers to the most fundamental questions about them. How does nature accelerate the highest energy particles in the universe? Do new interactions between them occur at such extreme energies? Are there unknown aspects of spacetime that can be uncovered by studying these particles?This book brings together three fields within 'extreme astronomy': ultra-high-energy cosmic ray physics, neutrino astronomy, and gamma-ray astronomy, and discusses how each can help answer these questions. Each field is presented with a theoretical introduction that clearly elucidates the key questions scientists face. This is followed by chapters that discuss the current set of experiments — how they work and their discoveries. Finally, new techniques and approaches are discussed to solve the mysteries uncovered by the current experiments.
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 Measurement of the Mass Composition of the Highest Energy Cosmic Rays with the Pierre Auger Observatory written by Alexander Edward Hervé and published by . This book was released on 2013 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin of ultra high energy cosmic rays is one of the big unsolved questions in Astrophysics today. Knowing the mass composition of these cosmic rays would help to determine information about both their propagation and acceleration. The Pierre Auger Observatory was built to gather more information and more statistics than any previous cosmic ray detector ever built. In this thesis, I will detail my method of extending the current Pierre Auger mass composition information by using surface array parameters as a proxy for the depth of shower maximum, an established mass indicator.
Download or read book A Combined Fit of Energy Spectrum Shower Depth Distributions and Arrival Directions of Ultra high energy Cosmic Rays Measured at the Pierre Auger Observatory written by Teresa Bister and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies written by and published by . This book was released on 2008 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of cosmic rays (CRs) with energies>57 EeV that suggests a correlation with the positions of active galactic nuclei (AGN) located within H"5 Mpc. However, this analysis does not take into account AGN morphology. A detailed study of the sample of AGN whose positions correlate with the CR events shows that most of them are classified as Seyfert 2 and low-ionization nuclear emission-line region (LINER) galaxies which do not differ from other local AGN of the same types. Therefore, the claimed correlation between the CR events observed by the Pierre Auger Observatory and local active galaxies should be considered as resulting from a chance coincidence, if the production of the highest energy CRs is not episodic in nature, but operates in a single object on long (e"Myr) timescales. Additionally, most of the selected sources do not show significant jet activity, and hence--in the framework of the jet paradigm--there are no reasons for expecting them to accelerate CRs up to the highest energies, H"02° eV, at all. If the extragalactic magnetic fields and the sources of these CRs are coupled with matter, it is possible that the deflection angle is larger than expected in the case of a uniform source distribution due to effectively larger fields. A future analysis has to take into account AGN morphology and may yield a correlation with a larger deflection angle and/or more distant sources. We further argue that Cen A alone could be associated with at least 4 events due to its large radio extent, and Cen B can be associated with more than 1 event due to its proximity to the Galactic plane and, correspondingly, the stronger Galactic magnetic field the ultra high energy CRs (UHECRs) encounter during propagation. If the UHECRs associated with these events are indeed accelerated by Cen A and Cen B, their deflection angles may provide information on the structure of the magnetic field in the direction of these putative sources. Future -ray observations (by, e.g., Gamma-Ray Large Area Space Telescope [GLAST], High Energy Stereoscopic System [HESS]) may provide additional clues to the nature of the accelerators of the UHECRs in the local Universe.
Download or read book The Principal Axes of the Directional Energy Distribution of Cosmic Rays Measured with the Pierre Auger Observatory written by Tobias Winchen and published by . This book was released on 2013 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Systematic Uncertainties in Cosmic Ray Energies Measured by the Auger Fluorescence Detectors written by Vanessa Catherine Holmes and published by . This book was released on 2011 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work investigates the processes used to reconstruct extensive air showers induced in the atmosphere by ultra high energy cosmic rays. It contributes to the efforts of the Pierre Auger Collaboration, whose members are working to solve many mysteries behind the phenomenon of these particles. Specifically my work has focused on the use of the Pierre Auger Observatory's fluorescence detectors to determine cosmic ray energies. I have investigated ways to reduce the systematic uncertainties involved in the reconstruction process. To accurately reconstruct an extensive air shower in order to determine properties of the primary cosmic ray, we need to be able to model how the atmosphere will affect its production and propagation. A precise knowledge of how to interpret the signals received at our detectors is also needed. Inaccurate models or incorrect assumptions may lead to large errors in the shape and magnitude of the true energy spectrum of the cosmic rays which we observe at Earth. We wish to use the information that we gather from this experiment about the energy spectrum, anisotropy and composition of cosmic rays to help locate and study sources, and the acceleration mechanisms that produce their incredible energies. If we are inaccurately reconstructing these extensive air showers then this could lead to incorrect theories being developed. The systematic uncertainties that I have investigated and are presented in my thesis are: An unexplained halo of light around the shower track at the fluorescence detector which led me to develop a parameterisation for singly scattered Cherenkov light that we receive at the fluorescence detectors. This parameterisation is a function of shower evolution, distance to the shower, scattering probability and angular distance from the tracks centre ; Uncertainty in the nitrogen fluorescence yield due to the humidity dependence of collisional quenching. To take this dependence into account I constructed monthly vapour pressure profiles using data acquired from radiosonde launches conducted above the Pierre Auger Observatory. As the fluorescence detectors are unable to detect air showers on overcast days, launches conducted in overcast conditions were identified and excluded, using infra-red cloud camera data and sky temperature measurements. Methods to reduce the uncertainty on the vapour pressure profiles uncertainties were also investigated ; Uncertainty in the methods used to interpret the light seen by the fluorescence detectors. When comparing two methods, I found that they differed in their approach to take into account the lateral shower width at large shower ages. This was because the initial parameterisation was only constructed up to shower ages of 1.2. I used the simulation package CORSIKA to check whether the original parameterisation was still valid at ages up to 1.5, and to check its validity down to primary particle energies of 1017eV. In addressing these systematic uncertainties, we now have a better understanding of the light that we receive at the Fluorescence Detectors, and of how to collect this light for use in reconstructing extensive air showers to determine the cosmic ray energy spectrum, cosmic ray composition and their arrival directions.
Download or read book Introduction To Ultrahigh Energy Cosmic Ray Physics written by Pierre Sokolsky and published by CRC Press. This book was released on 2018-03-08 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmic ray physics has recently attracted a great deal of attention from the high energy physics community because of the discovery of new sources and the advent of new techniques. The result of a series of lectures prepared for graduate students and postdoctoral researchers, this book is a general introduction to experimental techniques and results in the field of ultrahigh energy cosmic rays. It succinctly summarizes the rapidly developing field, and provides modern results that include data from newer detectors. Combining experiment and theory, the text explores the results of a single, easy-to-understand experiment to tie together various issues involved in the physics of ultrahigh energy cosmic rays.
Download or read book Update on the Correlation of the Highest Energy Cosmic Rays with Nearby Extragalactic Matter written by and published by . This book was released on 2010 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuzmin energy threshold, 6 x 1019 eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1{sup o} from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (386{sup +7})%, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of (6913{sup +11})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.
Download or read book Search for Anisotropy in the Arrival Directions of Ultra High Energy Cosmic Rays written by Aka G. Finci and published by . This book was released on 1975 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Composition Studies of Ultra High Energy Cosmic Rays Using Data of the Pierre Auger Observatory written by Karen Salomé Caballero Mora and published by . This book was released on 2010 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysical Aspects Of The Most Energetic Cosmic Rays Proceedings Of The Icrr International Symposium written by M Nagano and published by World Scientific. This book was released on 1991-07-23 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings present new results obtained from recent observations by the Haverah Park, Yakutsk, Fly's Eye and Akeno groups on the shape of the energy spectrum, the arrival direction (point source) and the nature of the most energetic cosmic rays. They also contain an in-depth discussion of the present status of observations on discrete sources at TeV and PeV energies. A detailed discussion of the physics problems related to the origin, acceleration mechanism and propagation of the most energetic cosmic rays in the galactic and extragalactic space is given in relation to observable features.
Download or read book Composition Analysis of Ultrahigh Energy Cosmic Rays Using the Pierre Auger Observatory Surface Detector written by David Scott Barnhill and published by . This book was released on 2006 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin and composition of ultrahigh energy cosmic rays has been and continues to be a topic of much study and debate. The Pierre Auger Observatory was designed to investigate the highest energy cosmic rays and resolve some of these problems. In this dissertation, I present a description of the Pierre Auger Observatory and a study of the performance of the surface array as well as work done on the photomultiplier tubes used in the surface array. I also present an analysis done on the composition of the events detected in the surface detector paying special attention to a photon primary assumption. Monte carlo simulations of extensive air showers are put through a simulation of the surface detector and observables are compared to real data. The mean behavior of the real data is compared to various baryonic primary assumptions. For photon primaries, a method is described to set an upper limit on the flux of photons based on comparing real events to expected distributions for photon initiated air showers. An upper limit on the photon flux is presented and compared with predictions from various exotic models of cosmic ray origins.
