摘要:

The evidence for the existence of cosmic rays with energies in excess of1020&hthinsp;eVis now overwhelming. There is so far no indication of the GZK cutoff in the energy spectrum at5×1019&hthinsp;eV.This conclusion is not firm for lack of statistics. A cutoff would be expected if the sources of the cosmic rays were distributed uniformly throughout the cosmos. The sources of cosmic rays with energy above the GZK cutoff must be at a distance ⩽100 Mpc, and if they are protons they are very likely to point to these sources. There are no easy explanations how known astrophysical objects can accelerate protons (or atomic nuclei) to these energies. The fluxes of these cosmic rays is very low and large instruments are required to observe them even with modest statistics. One such instrument, the Pierre Auger Observatory, is described. It is designed for all-sky coverage and the construction of its southern site in Argentina has begun. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378618

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

We consider the possibility to search for cosmic ray phenomena time correlated among distant experiments that are currently running in the world. In particular we consider the correlations of events detected by four experiments: between Milagro, operating in USA, and Cerro La Negra Cosmic Ray Laboratory, under construction in Mexico, and between Chacaltaya, in Bolivia, and Auger Observatory, under construction in Argentina. Almost complete sky coverage with fairly uniform celestial exposure of the northern and the southern hemispheres by the above four experiments at the same time could provide important information on astrophysical phenomena. Search for Gamma Ray Bursts and search for non random coincidence between these experiments seem to be feasible under an international extensive air shower joint experiment with the main goal to watch GRBs and other astrophysical phenomena. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378619

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The High Resolution Fly’s Eye Detector (HiRes) detects and measures properties of ultra high energy,E>1018&hthinsp;eV,cosmic rays. HiRes exploits what is known as the “Air Fluorescence” technique which uses the atmosphere as a calorimeter. A brief description of this technique and how it is used by the HiRes detector will be given in this paper. The HiRes detector has been operational with two detector sites separated by 12.6 km since spring 1999. The two separated “eyes” enable the HiRes detector to obtain stereoscopic observations of the air showers. We also have a data set obtained with the first of the 2 sites from 2.5 years of observations in monocular mode. Preliminary results from both the monocular and stereo analysis will be described. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378620

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The detection of particles with energies above1020&hthinsp;eVin giant airshowers continues to defy our attempts to understand them in physical terms. In this review I outline recent attempts to explain these events, usually as incoming protons. Options include decays of primordial particles, or interactions of decay products such as high energy neutrinos, Gamma Ray Bursts, pulsars, Lorentz invariance violation, and nearby radio galaxies. This last old proposal is the most mundane of all options, but also the most tested one. I will go through this last proposal in some detail, and clarify what work is there to do to prove or disprove it. At the end I put our current understanding of where cosmic rays at all energies come from into a skeptical synopsis. The new airshower detector systems which cover the Southern sky, AUGER and EUSO will provide the most critical tests. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378621

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The scientific goal of the KOSMOTEPETL program is to observe and to study ultra high energy cosmic rays through the fluorescent tracks that they produce in the Earth atmosphere with the help of satellite based optical cameras based on the technology of a large mirror-concentrator of light. At low orbits (400–600 km) a mirror with an area of 400 m2will allow us to observe neutrino induced horizontal tracks starting at the energy threshold of 1 EeV. With these neutrinos, which have to be produced in collisions of extreme energy cosmic rays (with energy >50 EeV) with background photons at distances >100 Mpc, the most distant cosmic ray sources will be revealed. Design of the TUS and KLYPVE detectors (the first detectors of the KOSMOTEPETL program with a mirror area 2 and 10 m2) is presented. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378622

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The KLYPVE optical detector on board the Russian segment of the ISS will observe 10 thousand km2of the Earth atmosphere registering the extremely high energy cosmic ray (EHECR) particles producing fluorescent tracks in the atmosphere. In this article the design of the detector is presented, including: the Fresnel type mirror of 10 m2area, the PMT retina of 2500 pixels, the pixel electronics, the data acquisition electronics, and the trigger system. The detector design is suited to conditions of the space experiment (wide range of temperature, short day-night cycle etc). The problem of selection of rare EHECR events in the presence of high intensity background light is discussed. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378623

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

It is reported the optical design of the Auger and Kosmotepetl projects. For the first one it was used a Schmidt camera without corrector plate and for the second one it is proposed to use a Fresnel mirror of low frequency with a stop located at the common curvature center in order to avoid the coma and astigmatism aberrations. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378624

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions for the highest energy events have strongly constrained most models proposed for the generation of these particles. An overview of the theoretical proposals are presented along with their most general signatures. Future experimental tests of the different proposals are discussed. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378625

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The mission “Extreme Universe Space Observatory - EUSO” is devoted to the investigation of the Extreme Energy Cosmic Rays (EECR withE>5×1019&hthinsp;eV) and of the High Energy Cosmic Neutrino flux looking at the streak of UV fluorescence light produced when the particles coming from Outer Space interact with the Earth’s atmosphere. EUSO will observe the fluorescence signal looking downward from Space the dark Earth atmosphere under a 60 degrees full field of view; the Fluorescence light will be imaged by a large Fresnel lens optics into a finely segmented focal plane detector. The segmentation and the time resolution adopted will consent to reconstruct the shower arrival direction and energy with high precision, EUSO is a collaborating effort of 27 research groups from Europe, U.S.A, and Japan and it has been designed to operate for more than 3 years mission life-time; it is expected to detect of the order of103/year EECRs withE>1020&hthinsp;eVand to open a window into the High Energy Neutrino Astronomy. Originally proposed to the European Space Agency as a Free Flyer Low Earth Orbit Mission, EUSO has been approved by ESA in march 2000 for an Accommodation Study on the International Space Station, with a goal for flight in 2006. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378626

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The observation of twenty cosmic-ray air-showers at and above1020&hthinsp;eVposes immediate problems for particle astrophysics: how the primary particles are accelerated to these energies, and how the primaries get here through the 2.7 K microwave background filling the Universe. In addition, the highest-energy events exhibit near-isotropy in the large, but a surprising small-scale clustering on the celestial sky. An overview of the puzzles is presented, followed by a discussion of many of the models proposed to solve these puzzles. Emphasis is placed on (i) the role neutrino primaries may play in resolving issues, and (ii) the natural manner in which hypothetical magnetic monopoles solve the acceleration and propagation problems. Finally, the many signatures by which cosmic ray experiments in the near future will discriminate among the proposed models are presented. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1378627

出版商:AIP    

年代:1901

数据来源: AIP