scholarly journals THE MYSTERIOUS ULTRAHIGH ENERGY COSMIC RAY CLUSTERING

2001 ◽  
Vol 16 (31) ◽  
pp. 2033-2045 ◽  
Author(s):  
LUIS A. ANCHORDOQUI ◽  
HAIM GOLDBERG ◽  
STEPHEN REUCROFT ◽  
JOHN SWAIN ◽  
GUSTAVO E. ROMERO ◽  
...  

We examine the correlation between compact radio quasars (redshifts in the range z=0.3–2.2) and the arrival direction of ultrahigh energy cosmic rays forming clusters. Our Monte Carlo simulation reveals a statistically significant correlation on the AGASA sample: the chance probability of this effect being less than 1%. The implications of this result on the origin of ultrahigh energy cosmic rays are discussed.

2019 ◽  
Vol 210 ◽  
pp. 04002
Author(s):  
James H. Matthews ◽  
Anthony R. Bell ◽  
Anabella T. Araudo ◽  
Katherine M. Blundell

The origin of ultrahigh energy cosmic rays (UHECRs) is an open question. In this proceeding, we first review the general physical requirements that a source must meet for acceleration to 10-100 EeV, including the consideration that the shock is not highly relativistic. We show that shocks in the backflows of radio galaxies can meet these requirements. We discuss a model in which giant-lobed radio galaxies such as Centaurus A and Fornax A act as slowly-leaking UHECR reservoirs, with the UHECRs being accelerated during a more powerful past episode. We also show that Centaurus A, Fornax A and other radio galaxies may explain the observed anisotropies in data from the Pierre Auger Observatory, before examining some of the difficulties in associating UHECR anisotropies with astrophysical sources.


2010 ◽  
Vol 25 (18) ◽  
pp. 1467-1481 ◽  
Author(s):  
TODOR STANEV

We introduce the highest energy cosmic rays and briefly review the powerful astrophysical objects where they could be accelerated. We then introduce the interactions of different cosmic ray particles with the photon fields of the Universe and the formation of the cosmic ray spectra observed at Earth. The last topic is the production of secondary gamma rays and neutrinos in the interactions of the ultrahigh energy cosmic rays.


2011 ◽  
Vol 20 (supp01) ◽  
pp. 118-131
Author(s):  
◽  
CAROLA DOBRIGKEIT

The Pierre Auger Observatory in Argentina is the largest cosmic ray detector array ever built. Its main goal is to measure cosmic rays of energy above 1018 eV with unprecedented statistics and precision. Although the construction of its baseline design was completed in mid-2008, the Observatory has been taking data continuously since January 2004. The main results obtained with the Pierre Auger Observatory are presented, with emphasis on the energy spectrum and studies of composition and arrival directions of the ultrahigh energy cosmic rays. Features observed in the energy spectrum are discussed. Results about cosmic ray composition inferred from systematic studies of the average depth of shower maximum and its fluctuations are reviewed. Recent results of studies of arrival direction distributions and correlations with nearby extragalactic objects are presented.


2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Jiali Liu ◽  
Qunyu Yang ◽  
Yunxiang Bai ◽  
Zhen Cao

A fluorescence telescope tower array has been designed to measure cosmic rays in the energy range of 1017–1018 eV. A full Monte Carlo simulation, including air shower production, light generation and propagation, detector response, electronics, and trigger system, has been developed for that purpose. Using such a simulation tool, the detector configuration, which includes one main tower array and two side-trigger arrays, 24 telescopes in total, has been optimized. The aperture and the event rate have been estimated. Furthermore, the performance of theXmax⁡technique in measuring composition has also been studied.


2006 ◽  
Vol 84 (6-7) ◽  
pp. 537-543
Author(s):  
R Dick ◽  
K M Hopp ◽  
K E Wunderle

The phase of inflationary expansion in the early Universe produces superheavy relics in a mass window between 1012 and 1014 GeV. Decay or annihilation of these superheavy relics an explain the observed ultrahigh-energy cosmic rays beyond the Greisen–Zatsepin–Kuzmin cutoff. We emphasize that the pattern of cosmic-ray arrival directions seen by the Pierre Auger observatory will decide between the different proposals for the origin of ultrahigh-energy cosmic rays.PACS Nos.: 98.70.Sa, 98.70.–f, 95.35.+d, 14.80.–j


2011 ◽  
Vol 01 ◽  
pp. 163-170
Author(s):  
CHIA-CHUN LU ◽  
GUEY-LIN LIN

Motivated by Pierre Auger results on the energy spectrum and the anisotropy of ultrahigh energy cosmic rays (UHECR), we study the spatial distributions of UHECR sources by fitting to the measured UHECR spectrum. We consider possible energy calibration effects in the Pierre Auger data for our analysis. We propose a local overdensity of UHECR sources which is testable in the future cosmic ray astronomy.


2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.


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