Download or read book Correlation of the Highest Energy Cosmic Rays with Nearby Extragalactic Objects written by and published by . This book was released on 2007 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above (almost equal to) 6 x 1019 eV and the positions of active galactic nuclei (AGN) lying within (almost equal to) 75 Mpc. We reject the hypothesis of an isotropic distribution of these cosmic rays at over 99% confidence level from a prescribed a priori test. The correlation we observe is compatible with the hypothesis that the highest energy particles originate from nearby extragalactic sources whose flux has not been significantly reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.
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 Correlation of the Highest energy Cosmic Rays with the Positions of Nearby Active Galactic Nuclei written by and published by . This book was released on 2007 with total page 33 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 the cosmic rays with the highest energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [1]. The correlation has maximum significance for cosmic rays with energy greater than (almost equal to) 6 x 1019 eV and AGN at a distance less than (almost equal to) 75 Mpc. We have confirmed the anisotropy at a confidence level of more than 99% through a test with parameters specified a priori, using an independent data set. The observed correlation is compatible with the hypothesis that cosmic rays with the highest energies originate from extra-galactic sources close enough so that their flux is not significantly attenuated by interaction with the cosmic background radiation (the Greisen-Zatsepin-Kuzmin effect). The angular scale of the correlation observed is a few degrees, which suggests a predominantly light composition unless the magnetic fields are very weak outside the thin disk of our galaxy. Our present data do not identify AGN as the sources of cosmic rays unambiguously, and other candidate sources which are distributed as nearby AGN are not ruled out. We discuss the prospect of unequivocal identification of individual sources of the highest-energy cosmic rays within a few years of continued operation of the Pierre Auger Observatory.
Download or read book Searches for Anisotropies in the Arrival Directions of the Highest Energy Cosmic Rays Detected by the Pierre Auger Observatory written by and published by . This book was released on 2015 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: We analyze the distribution of arrival directions of ultra-high-energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to 80°, thus covering from -90° to +45° in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the Véron-Cetty and Véron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes, self-clustering of event directions at angular scales up to 30°, and different threshold energies between 40 and 80 EeV. We then look for correlations of cosmic rays with celestial structures both in the Galaxy (the Galactic Center and Galactic Plane) and in the local universe (the Super-Galactic Plane). We also examine their correlation with different populations of nearby extragalactic objects: galaxies in the 2MRS catalog, AGNs detected by Swift-BAT, radio galaxies with jets, and the Centaurus A (Cen A) galaxy. None of the tests show statistically significant evidence of anisotropy. As a result, the strongest departures from isotropy (post-trial probability $\sim 1.4$%) are obtained for cosmic rays with $E\gt 58$ EeV in rather large windows around Swift AGNs closer than 130 Mpc and brighter than 1044 erg s-1 (18° radius), and around the direction of Cen A (15° radius).
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 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 Introduction To Ultrahigh Energy Cosmic Ray Physics written by Pierre Sokolsky and published by CRC Press. This book was released on 2020-10-26 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: This revised edition provides an up-to-date summary of the field of ultra-high energy cosmic rays, dealing with their origin, propagation, and composition,. The authors reflect the enormous strides made since the first edition in the realm of experimental work, in particular the use of vastly improved, more sensitive and precise detectors. The level remains introductory and pedagogical, suitable for students and researchers interested in moving into this exciting field. Throughout the text, the authors focus on giving an introductory overview of the key physics issues, followed by a clear and concise description of experimental approaches and current results. Key Features: Updates the most coherent summary of the field available, with new text that provides the reader with clear historical context. Brand new discussion of contemporary space-based experiments and ideas for extending ground-based detectors. Completely new discussion of radio detection methods. Includes a new chapter on small to intermediate-scale anisotropy. Offers new sections on modern hadronic models and software packages to simulate showers.
Download or read book Cosmic Magnetic Fields written by and published by Cambridge University Press. This book was released on with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Classifying the Cosmos written by Steven J. Dick and published by Springer. This book was released on 2019-03-21 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the invention of the telescope 400 years ago, astronomers have rapidly discovered countless celestial objects. But how does one make sense of it all? Astronomer and former NASA Chief Historian Steven J. Dick brings order to this menagerie by defining 82 classes of astronomical objects, which he places in a beginner-friendly system known as "Astronomy’s Three Kingdoms.” Rather than concentrating on technicalities, this system focuses on the history of each object, the nature of its discovery, and our current knowledge about it. The ensuing book can therefore be read on at least two levels. On one level, it is an illustrated guide to various types of astronomical wonders. On another level, it is considerably more: the first comprehensive classification system to cover all celestial objects in a consistent manner. Accompanying each spread are spectacular historical and modern images. The result is a pedagogical tour-de-force, whereby readers can easily master astronomy’s three realms of planets, stars, and galaxies.
Download or read book The ubiquitous mechanism accelerating cosmic rays at all the energies written by Antonio Codino and published by Società Editrice Esculapio. This book was released on 2021-02-04 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanism accelerating Cosmic rays in the milky way galaxy and galaxy clusters is identified and described. The acceleration of Cosmic rays is a purely electrostatic process which operate up to the maximum energies of 1023 ev in galaxy clusters. Galactic Cosmic rays are accelerated in a pervasive electrostatic field active in the whole galaxy except in restricted regions shielded by Interstellar and stellar plasma as, for instance, the region occupied by the Solar system. It is proved that the Energy spectrum of the Cosmic radiation in the milky way galaxy, in the region where the Solar system resides, has a constant Spectral index comprised between 2.64-2.68 and the maximum energies of galactic protons are 3.0 × 1019 ev. The agreement of these results with the experimental data is discussed in detail and highlighted. The various physical processes that maintain the stability of the electrostatic structure in the milky way galaxy are the same that generate the galactic magnetic field. Accordingly, the intensity, orientation and direction of the galactic magnetic field are evaluated. The results of the calculation are compared with the observation data, optical and mostly radio astronomi data. The accord of the intensity, orientation and direction of the observed magnetic field with calculation is excellent.
Download or read book Particles and Astrophysics written by Maurizio Spurio and published by Springer. This book was released on 2014-10-06 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an introduction to “multi-messenger” astrophysics. It covers the many different aspects connecting particle physics with astrophysics and cosmology and introduces astrophysics using numerous experimental findings recently obtained through the study of high-energy particles. Taking a systematic approach, it comprehensively presents experimental aspects from the most advanced laboratories and detectors, as well as the theoretical background. The book is aimed at graduate students and post-graduate researchers with a basic understanding of particle and nuclear physics. It will also be of interest to particle physicists working in accelerator/collider physics who are keen to understand the mechanisms of the largest accelerators in the Universe. The book draws on the extensive lecturing experience of Professor Maurizio Spurio from the University of Bologna.
Download or read book Topics in Cosmic ray Astrophysics written by Michael DuVernois and published by Nova Biomedical Books. This book was released on 1999 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents recent findings on charged cosmic rays, primarily nuclei, from galactic and extra-galactic sources. Chapters on new and proposed instruments and techniques examine projects such as the SilEye and the PAMELA apparatus for the search of antimatter in cosmic rays. Papers on cosmic ray models look at nonlinear phenomena in diffusive shock acceleration, and propagation of cosmic rays in the galaxy. Material on cosmic ray sources and ultra-high energy cosmic rays examine source composition and its relation to the interstellar matter, and cosmic ray mass composition at highest energies. The editor is a researcher at Pennsylvania State University. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book Nonlinear Cosmic Ray Diffusion Theories written by Andreas Shalchi and published by Springer Science & Business Media. This book was released on 2009-06-04 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: If charged particles move through the interplanetary or interstellar medium, they interact with a large-scale magnetic ?eld such as the magnetic ?eld of the Sun or the Galactic magnetic ?eld. As these background ?elds are usually nearly constant in time and space, they can be approximated by a homogeneous ?eld. If there are no additional ?elds, the particle trajectory is a perfect helix along which the par- cle moves at a constant speed. In reality, however, there are turbulent electric and magnetic?elds dueto the interstellaror solar wind plasma. These ?elds lead to sc- tering of the cosmic rays parallel and perpendicular to the background ?eld. These scattering effects, which usually are of diffusive nature, can be described by s- tial diffusion coef?cients or, alternatively, by mean free paths. The knowledge of these parameters is essential for describing cosmic ray propagation as well as d- fusive shock acceleration. The latter process is responsible for the high cosmic ray energies that have been observed. The layout of this book is as follows. In Chap. 1, the general physical scenario is presented. We discuss fundamental processes such as cosmic ray propagation and acceleration in different systems such as the solar system or the interst- lar space. These processes are a consequence of the interaction between charged cosmic particles and an astrophysical plasma (turbulence). The properties of such plasmas are therefore the subject of Chap. 2.
Download or read book Very High Energy Phenomena in the Universe written by Yannick Giraud-Héraud and published by Atlantica Séguier Frontières. This book was released on 1997 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Energy Cosmic Rays written by Todor Stanev and published by Springer Science & Business Media. This book was released on 2010-03-10 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers an accessible text and reference (a cosmic-ray manual) for graduate students entering the field and high-energy astrophysicists will find this an accessible cosmic-ray manual Easy to read for the general astronomer, the first part describes the standard model of cosmic rays based on our understanding of modern particle physics. Presents the acceleration scenario in some detail in supernovae explosions as well as in the passage of cosmic rays through the Galaxy. Compares experimental data in the atmosphere as well as underground are compared with theoretical models
Download or read book The Hidden Link Between Earth s Magnetic Field and Climate written by Kilifarska N.A. and published by Elsevier. This book was released on 2020-06-19 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hidden Link Between Earth's Magnetic Field and Climate offers a new framework of understanding and interpretation for both well-known and less known relations between different geophysical and meteorological variables which can improve the quality of climate modeling. The book reviews the most current research on both current and paleo data to introduce a causal chain of interactions between the geomagnetic field, energetic particles which bombard the Earth's atmosphere, ozone and humidity near the tropopause, and surface temperature. The impacts of these complicated interactions is not uniformly distributed over the globe, thus contributing to our understanding of regional differences in climatic changes and the asymmetrical ozone distribution over the globe. - Covers the newly discovered autocatalytic cycle for ozone production in the lower stratosphere, providing a better understanding of the heterogeneous distribution of ozone globally - Outlines a mechanism for the lower stratospheric ozone influence on the temperature and humidity of the upper troposphere - Provides a single resource on research in energetic particles' modulation by heterogeneous geomagnetic fields, mechanisms of the influence of particles on the atmospheric ozone, and the influence of ozone on climate
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.
