scholarly journals Superheavy dark matter and ultrahigh-energy cosmic rays

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

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.


2019 ◽  
Vol 1208 ◽  
pp. 012013
Author(s):  
Alan G. Chávez-Meza ◽  
Juan C. Arteaga-Velázquez ◽  
Luis M. Villaseñor-Cendejas

2019 ◽  
Vol 209 ◽  
pp. 01002
Author(s):  
Esteban Roulet

I describe some of the results on ultrahigh-energy cosmic rays that have been obtained with the Pierre Auger Observatory. These include measurements of the spectrum, composition and anisotropies. Possible astrophysical scenarios that account for these results are discussed.


2019 ◽  
Vol 210 ◽  
pp. 06003
Author(s):  
Toshihiro Fujii ◽  
Max Malacari ◽  
Justin Albury ◽  
Jose A. Bellido ◽  
Ladislav Chytka ◽  
...  

The origin and nature of ultrahigh-energy cosmic rays (UHECRs) is one of the most intriguing and important mysteries in astroparticle physics. The two largest observatories currently in operation, the Telescope Array Experiment in central Utah, USA, and the Pierre Auger Observatory in western Argentina, have been steadily observing UHECRs in both hemispheres for over a decade. We highlight the latest results from both of these experiments, and address the requirements for a next-generation UHECR observatory. The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for a next-generation UHECR observa-tory, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays with an unprecedented aperture. We have developed a full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. Over the last three years, we installed three such prototypes at the Black Rock Mesa site of the Telescope Array Experiment. These telescopes have been steadily taking data since installation. We report on preliminary results of the full-scale FAST prototypes, including measurements of distant ultraviolet lasers and UHECRs. Futhermore, we discuss our plan to install an additional identical FAST prototype at the Pierre Auger Observatory. Possible benefits to the Telescope Array and the Pierre Auger Observatory include a comparison of the transparency of the atmosphere above both experiments, a study of the systematic uncertainty associated with their existing fluorescence detectors, and a cross-calibration of their energy and Xmax scales.


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 197 ◽  
pp. 02001
Author(s):  
Bianca Keilhauer

The Pierre Auger Observatory for detecting ultrahigh energy cosmic rays has been founded in 1999. After a main planning and construction phase of about five years, the regular data taking started in 2004, but it took another four years until the full surface detector array was deployed. In parallel to the main detectors of the Observatory, a comprehensive set of instruments for monitoring the atmospheric conditions above the array was developed and installed as varying atmospheric conditions influence the development and detection of extensive air showers. The multitude of atmospheric monitoring installations at the Pierre Auger Observatory will be presented as well as the challenges and efforts to run such instruments for several decades.


Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 128 ◽  
Author(s):  
Dariusz Góra ◽  

The Pierre Auger Observatory is the world’s largest operating detection system for the observation of ultra high energy cosmic rays (UHECRs), with energies above 10 17 eV. The detector allows detailed measurements of the energy spectrum, mass composition and arrival directions of primary cosmic rays in the energy range above 10 17 eV. The data collected at the Auger Observatory over the last decade show the suppression of the cosmic ray flux at energies above 4 × 10 19 eV. However, it is still unclear if this suppression is caused by the energy limitation of their sources or by the Greisen–Zatsepin–Kuzmin (GZK) cut-off. In such a case, UHECRs would interact with the microwave background (CMB), so that particles traveling long intergalactic distances could not have energies greater than 5 × 10 19 eV. The other puzzle is the origin of UHECRs. Some clues can be drawn from studying the distribution of their arrival directions. The recently observed dipole anisotropy has an orientation that indicates an extragalactic origin of UHECRs. The Auger surface detector array is also sensitive to showers due to ultra high energy neutrinos of all flavors and photons, and recent neutrino and photon limits provided by the Auger Observatory can constrain models of the cosmogenic neutrino production and exotic scenarios of the UHECRs origin, such as the decays of super heavy, non-standard-model particles. In this paper, the recent results on measurements of the energy spectrum, mass composition and arrival directions of cosmic rays, as well as future prospects are presented.


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