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Update On The Correlation Of The Highest Energy Cosmic Rays With Nearby Extragalactic Matter
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Book Synopsis Update on the Correlation of the Highest Energy Cosmic Rays with Nearby Extragalactic Matter by :
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.
Book Synopsis Correlation of the Highest Energy Cosmic Rays with Nearby Extragalactic Objects by :
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.
Book Synopsis Correlation of the Highest-energy Cosmic Rays with the Positions of Nearby Active Galactic Nuclei by :
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.
Book Synopsis Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory by :
Download or read book Astrophysical Sources of Cosmic Rays and Related Measurements with the Pierre Auger Observatory written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Correlation of the highest energy cosmic rays with nearby extragalactic objects in Pierre Auger Observatory data; (2) Discriminating potential astrophysical sources of the highest energy cosmic rays with the Pierre Auger Observatory; (3) Intrinsic anisotropy of the UHECR from the Pierre Auger Observatory; (4) Ultra-high energy photon studies with the Pierre Auger Observatory; (5) Limits on the flux of diffuse ultra high energy neutrinos set using the Pierre Auger Observatory; (6) Search for sidereal modulation of the arrival directions of events recorded at the Pierre Auger Observatory; (7) Cosmic Ray Solar Modulation Studies in the Pierre Auger Observatory; (8) Investigation of the Displacement Angle of the Highest Energy Cosmic Rays Caused by the Galactic Magnetic Field; (9) Search for coincidences with astrophysical transients in Pierre Auger Observatory data; and (10) An alternative method for determining the energy of hybrid events at the Pierre Auger Observatory.
Book Synopsis On the Possible Association of Ultra High Energy Cosmic Rays with Nearby Active Galaxies by :
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.
Book Synopsis Very High Energy Phenomena in the Universe by : Yannick Giraud-Héraud
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:
Book Synopsis Very High Energy Cosmic Gamma Radiation by : Felix A. Aharonian
Download or read book Very High Energy Cosmic Gamma Radiation written by Felix A. Aharonian and published by World Scientific. This book was released on 2004 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma ray astronomy, the branch of high energy astrophysics that studies the sky in energetic ?-ray photons, is destined to play a crucial role in the exploration of nonthermal phenomena in the Universe in their most extreme and violent forms. The great potential of this discipline offers impressive coverage of many OC hot topicsOCO of modern astrophysics and cosmology, such as the origin of galactic and extragalactic cosmic rays, particle acceleration and radiation processes under extreme astrophysical conditions, and the search for dark matter."
Book Synopsis Topics in Cosmic-ray Astrophysics by : Michael DuVernois
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 Cosmic Rays written by and published by . This book was released on 1994 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis High Energy Cosmic Rays by : Todor Stanev
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 Pierre Auger Results written by and published by . This book was released on 2008 with total page 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 6 [1] 1019 eV and the positions of active galactic nuclei (AGN) lying within 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 relatively nearby extragalactic sources whose fluxes have therefore not been significantly reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.
Book Synopsis Cosmic-ray Astronomy at the Highest Energies with Ten Years of Data of the Pierre Auger Observatory by : Lorenzo Caccianiga
Download or read book Cosmic-ray Astronomy at the Highest Energies with Ten Years of Data of the Pierre Auger Observatory written by Lorenzo Caccianiga and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Identifying the sources of the ultra-high energy cosmic rays (UHECRs, above 10^{18} eV), the most energetic particles known in the universe, would be an important leap forward for both the astrophysics and particle physics knowledge. However, developing a cosmic-ray astronomy is arduous because magnetic fields, that permeate our Galaxy and the extra-Galactic space, deflect cosmic rays that may lose the directional information on their sources. This problem can be reduced by studying the highest energy end of the cosmic ray spectrum. Indeed, magnetic field deflections are inversely proportional to the cosmic ray energy. Moreover, above 4x10^{19} eV, cosmic rays interact with cosmic photon backgrounds, losing energy. This means that the sources of the highest energy cosmic rays observed on Earth can be located only in the nearby universe (200 Mpc or less). The largest detector ever built for detecting cosmic rays at such high energies is the Pierre Auger Observatory, in Argentina. It combines a 3000 km^2 surface array of water Cherenkov detectors with fluorescence telescopes to measure extensive air showers initiated by the UHECRs. This thesis was developed inside the Auger Collaboration and was devoted to study the highest energy events observed by Auger, starting from the selection and reconstruction up to the analysis of their distribution in the sky. Moreover, since the composition at these energies is unknown, we developed a method to select proton-like events, since high Z cosmic rays are too much deflected by magnetic fields to be used for cosmic-ray astronomy.
Book Synopsis Introduction To Ultrahigh Energy Cosmic Ray Physics by : Pierre Sokolsky
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 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 Cosmic Rays written by Steff Jaywan and published by Dedona Publishing. This book was released on with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmic rays are an intriguing aspect of astrophysics, originating from various sources in the universe, such as supernovae, pulsars, and even black holes. They consist of charged particles accelerated to incredible energies, often far beyond what our most powerful particle accelerators on Earth can achieve. These particles, when they collide with the Earth's atmosphere, create secondary particles in a cascade of interactions, leading to a fascinating array of phenomena. Studying cosmic rays provides valuable insights into the universe's most extreme environments and processes. They offer clues about the composition of cosmic objects, the nature of dark matter, and the magnetic fields permeating space. Moreover, understanding cosmic rays is crucial for space exploration, as they pose radiation hazards to astronauts and spacecraft. Researchers use ground-based detectors, high-altitude balloons, and even satellites to study cosmic rays from different vantage points. By analyzing the energy spectrum, arrival directions, and particle types, scientists aim to unlock the mysteries surrounding these enigmatic messengers from the cosmos.
Book Synopsis Cosmic Rays by : Zbigniew Szadkowski
Download or read book Cosmic Rays written by Zbigniew Szadkowski and published by BoD – Books on Demand. This book was released on 2018-08-22 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements in present experiments have dramatically advanced our understanding of ultrahigh-energy cosmic rays. The suppression of the flux at the highest energies is now confirmed without any doubt, and strong limits have been placed on the photon and neutrino components. There are indications for a small, large-scale anisotropy both below and above the energy of the angle and for a correlation on smaller angular scales at E > 5.5*1019 eV. Around 3*1018 eV, there is a distinct change of slope with energy, and the shower-to-shower variance decreases. Interpreted with the leading LHC-tuned shower models, this implies a gradual shift to a heavier composition, and a number of fundamentally different astrophysical model scenarios have been developed to describe this evolution.
Book Synopsis The Astronomy Revolution by : Donald G. York
Download or read book The Astronomy Revolution written by Donald G. York and published by Taylor & Francis. This book was released on 2016-04-19 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some 400 years after the first known patent application for a telescope by Hans Lipperhey, The Astronomy Revolution: 400 Years of Exploring the Cosmos surveys the effects of this instrument and explores the questions that have arisen out of scientific research in astronomy and cosmology. Inspired by the international New Vision 400 conference held
