Download or read book Large scale Anisotropies in the High Energy Cosmic Ray Sky written by Moritz Münchmeyer and published by . This book was released on 2012 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coverage and large scale anisotropies estimation methods for the Pierre Auger Observatory written by J. Ch Hamilton and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new method, developed for the Auger Observatory, based on a smooth estimate of the zenith angle distribution obtained from the data itself (which is essentially unchanged in the case of the presence of a large scale anisotropy pattern). We also study the sensitivity of several methods to detect large-scale anisotropies in the cosmic ray arrival direction distribution : Rayleigh analysis, dipole fitting and angular power spectrum estimation.
Download or read book Full Sky Search for Ultrahigh Energy Cosmic Ray Anisotropies written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Using data from the SUGAR and the AGASA experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for anisotropy patterns in the arrival directions of cosmic rays with energies> 10{sup 19.6} eV. We determine the angular power spectrum from an expansion in spherical harmonics for modes out to l = 5. Based on available statistics, we find no significant deviation from isotropy. We compare the rather modest results which can be extracted from existing data samples with the results that should be forthcoming as new full-sky observatories begin operation.
Download or read book First Hints of Large Scale Structures in the Ultrahigh Energy Sky written by and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The result of the recent publication [1] of a broad maximum around 25 degrees in the two-point autocorrelation function of ultra-high energy cosmic ray arrival directions has been intriguingly interpreted as the first imprint of the large scale structures (LSS) of baryonic matter in the near universe. We analyze this suggestion in light of the clustering properties expected from the PSCz astronomical catalogue of LSS. The chance probability of the signal is consistent within 2 [sigma] with the predictions based on the catalogue. No evidence for a significant cross-correlation of the observed events with known overdensities in the LSS is found, which may be due to the role of the galactic and extragalactic magnetic fields, and is however consistent with the limited statistics. The larger statistics to be collected by the Pierre Auger Observatory is needed to answer definitely the question.
Download or read book Methods for the Reconstruction of Large Scale Anisotropies of the Cosmic Ray Flux written by Sven Over and published by . This book was released on 2009 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Systematic Studies of Cosmic ray Anisotropy and Energy Spectrum with IceCube and IceTop written by and published by . This book was released on 2015 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anisotropy in the cosmic-ray arrival direction distribution has been well documented over a large energy range, but its origin remains largely a mystery. In the TeV to PeV energy range, the galactic magnetic field thoroughly scatters cosmic rays, but anisotropy at the part-per-mille level and smaller persists, potentially carrying information about nearby cosmic-ray accelerators and the galactic magnetic field. The IceCube Neutrino Observatory was the first detector to observe anisotropy at these energies in the Southern sky. This work uses 318 billion cosmic-ray induced muon events, collected between May 2009 and May 2015 from both the in-ice component of IceCube as well as the surface component, IceTop. The observed global anisotropy features large regions of relative excess and deficit, with amplitudes on the order of $10^{-3}$. While a decomposition of the arrival direction distribution into spherical harmonics shows that most of the power is contained in the low-multipole ($\ell \leq 4$) moments, higher-multipole components are found to be statistically significant down to an angular scale of less than $10^{\circ}$, approaching the angular resolution of the detector. Above 100\,TeV, a change in the topology of the arrival direction distribution is observed, and the anisotropy is characterized by a wide relative deficit whose amplitude increases with primary energy up to at least 5\,PeV, the highest energies currently accessible to IceCube with sufficient event statistics. No time dependence of the large- and small-scale structures is observed in the six-year period covered by this analysis within statistical and systematic uncertainties. Analysis of the energy spectrum and composition in the PeV energy range as a function of sky position is performed with IceTop data over a five-year period using a likelihood-based reconstruction. Both the energy spectrum and the composition distribution are found to be consistent with a single source population over declination bands. This work represents an early attempt at understanding the anisotropy through the study of the spectrum and composition. The high-statistics data set reveals more details on the properties of the anisotropy, potentially able to shed light on the various physical processes responsible for the complex angular structure and energy evolution.
Download or read book Small Scale Anisotropies of UHECRs from Super heavy Halo Dark Matter written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The decay of very heavy metastable relics of the Early Universe can produce ultra-high energy cosmic rays (UHECRs) in the halo of our own Galaxy. In this model, no Greisen-Zatsepin-Kuzmin cutoff is expected because of the short propagation distances. They show here that, as a consequence of the hierarchical build up of the halo, this scenario predicts the existence of small scale anisotropies in the arrival directions of UHECRs, in addition to a large scale anisotropy, known from previous studies. They also suggest some other observable consequences of this scenario which will be testable with upcoming experiments, as Auguer, EUSO and OWL.
Download or read book Very High Energy Cosmic ray Interactions written by and published by . This book was released on 2000 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics At Ultra high Energies Proceedings Of The 15th Course Of The International School Of Cosmic Ray Astrophysics written by Maurice M Shapiro and published by World Scientific. This book was released on 2007-11-22 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces young researchers to the exciting field of ultra-high energy astrophysics including charged particles, gamma rays and neutrinos. At ultra-high energy the radiation is produced by interactions of cosmic ray particles accelerated in explosive events such as supernovae or hypernovae, black holes or, possibly, the big bang. Through direct contact with senior scientists, now actively planning the next generation of experiments/models, the excitement and motivation for research at ultra-high energy was conveyed. The underpinning of these fields is a synthesis of knowledge and techniques from nuclear and particle physics, astronomy and cosmology. Informing the participants of this background, how it was derived, and the new challenges for the future are the major goal. Further, the course has helped to foster new astrophysical research and promoted contacts, which have resulted in new collaborations.
Download or read book Low Energy Cosmic Ray Anisotropies Observed Using the Pierre Auger Observatory written by Kerridwen Bette Barber and published by . This book was released on 2014 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pierre Auger Observatory is a hybrid cosmic ray detector located in the high plains of Argentina. It comprises an array of water-Cherenkov stations overlooked by four fluorescence detector sites and was designed and built for the purpose of studying ultra-high energy cosmic rays (>1018 eV). Due to the distribution of cosmic ray energies following a power law, in the process of studying these high energy events, the observatory also collects vast amounts of data on lower energy cosmic ray events. The low solar activity of the 2006 to 2009 period presents an opportunity to study the behaviour of the very low cosmic ray flux which would otherwise be overwhelmed by the solar wind during more active periods. This research aims to investigate the anisotropy in the low energy cosmic ray flux in the southern hemisphere using the calibration data for the Pierre Auger Observatory's surface detector. The energy ranges accessible via these calibration data were determined via numerical simulation of both air shower propagation through the atmosphere as well as the surface detector response to the surface particles, and were found to be of the order of 100 GeV. Following corrections to remove atmospheric and other spurious effects, investigations into the anisotropy present in the data were performed in both solar and sidereal time, spanning periods of both low and high solar activity.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-12 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 2005 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Early Universe and the Cosmic Microwave Background Theory and Observations written by Norma G. Sànchez and published by Springer Science & Business Media. This book was released on 2003-12-31 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of the Daniel Chalonge School on Astrofundamental Physics is to contribute to a theory of the universe (and particularly of the early universe) up to the marks, and at the scientific height of, the unprecedented accuracy, existent and expected, in the observational data. The impressive development of modern cosmology during the last decades is to a large extent due to its unification with elementary particle physics and quantum field theory. The cross-section between these fields has been increasing setting up Astrofundamental Physics. The early universe is an exceptional (theoretical and experimental) laboratory in this new discipline. This NATO Advanced Study Institute provided an up dated understanding, from a fundamental physics and deep point of view, of the progress and key issues in the early universe and the cosmic microwave background: theory and observations. The genuine interplay with large scale structure formation and dark matter problem were discussed. The central focus was placed on the cosmic microwave background. Emphasis was given to the precise inter-relation between fundamental physics and cosmology in these problems, both at the theoretical and experimental/observational levels, within a deep and well defined programme which provided in addition, a careful interdisciplinarity. Special sessions were devoted to high energy cosmic rays, neutrinos in astrophysics, and high energy astrophysics. Deep understanding, clarification, synthesis, careful interdisciplinarity within a fundamental physics framework, were the main goals of the course.
Download or read book Radiative Transfer written by Subrahmanyan Chandrasekhar and published by Courier Corporation. This book was released on 2013-04-15 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book by a Nobel Laureate provides the foundation for analysis of stellar atmospheres, planetary illumination, and sky radiation. Suitable for students and professionals in physics, nuclear physics, astrophysics, and atmospheric studies. 1950 edition.
Download or read book Gamma ray and Neutrino Signatures of Galactic Cosmic ray Accelerators written by Silvia Celli and published by Springer Nature. This book was released on 2019-12-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses three “hot” topics concerning the general problem of the origin of Galactic cosmic rays, namely (1) the acceleration, propagation, and radiation of particles in supernova remnants; (2) very high energy neutrinos from the Galactic Center; and (3) the potential held by the next-generation gamma-ray and neutrino detectors CTA and KM3NeT for studying extended non-thermal sources in the Galaxy. The topics are intrinsically connected to determining the nature (“hadronic or leptonic?”) of gamma-ray emissions from young and middle-aged supernova remnants and the search for cosmic-ray PeVatrons. The results and conclusions provided here are based on extensive analytical and numerical simulations, which are formulated and presented in a straightforward format that can be readily used in the interpretations of gamma-ray and neutrino observations, as well as for confident predictions for future measurements.
Download or read book New Worlds In Astroparticle Physics Proceedings Of The International Workshop written by Ana Maria Mourao and published by World Scientific. This book was released on 1998-05-14 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the first meeting on “New Worlds in Astroparticle Physics” focus on the joint field of particle physics and astrophysics. This is a field widely open to both theory and experiment. Important questions of particle physics — from the role of the Higgs scalar to the deconfined QCD phase, the developments beyond the Standard Model and the subtle behavior of neutrinos — are discussed. The same is true for the relevant questions in astrophysics and cosmology — from the fluctuations in the photon background radiation to large scale structure formation, dark matter searches and the origin of cosmic rays at very high energies. The two viewpoints, from the small sizes or from the large scales, are convergent and reveal the same universe: the universe of astroparticle physics.
Download or read book Cosmology and Particles written by Jean Audouze and published by Atlantica Séguier Frontières. This book was released on 1981 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
