scholarly journals High Energy Cosmic Rays from Young Neutron Stars

1987 ◽  
Vol 125 ◽  
pp. 554-554
Author(s):  
Shigeki Miyaji
Keyword(s):  
Chemical Composition ◽  
Cosmic Rays ◽  
Energy Range ◽  
Neutron Stars ◽  
Cosmic Ray ◽  
High Energy ◽  
Heavy Nuclei ◽  
Intensity Enhancement ◽  
High Energy Cosmic Rays ◽  
High Energies

Cosmic ray spectrum has an intensity enhancement at energy range 1014–16 eV/nuc. Recently Takahasi et al. (1986) called an attention to chemical composition there. Although the data still contain large uncertainties, they argued an overabundance of calcium at high energies (Ca/Fe ≥ 2 above 1014 eV/nucleus) and some enhancements of medium heavy nuclei (C ∼ Ar) instead of no anomalous p, He, and Fe abundances.

scholarly journals ACTIVE GALACTIC NUCLEI: SOURCES FOR ULTRA HIGH ENERGY COSMIC RAYS

2009 ◽  
Vol 18 (10) ◽  
pp. 1577-1581 ◽  
Author(s):  
P. L. BIERMANN ◽  
J. K. BECKER ◽  
L. CARAMETE ◽  
L. GERGELY ◽  
I. C. MARIŞ ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Radio Galaxy ◽  
Galactic Nuclei ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Ultra High Energy ◽  
Heavy Nuclei ◽  
High Energy Cosmic Rays ◽  
Relativistic Jet

Ultra high energy cosmic ray events presently show a spectrum, which we interpret here as galactic cosmic rays due to a starburst, in the radio galaxy Cen A which is pushed up in energy by the shock of a relativistic jet. The knee feature and the particles with energy immediately higher in galactic cosmic rays then turn into the bulk of ultra high energy cosmic rays. This entails that all ultra high energy cosmic rays are heavy nuclei. This picture is viable if the majority of the observed ultra high energy events come from the radio galaxy Cen A, and are scattered by intergalactic magnetic fields across much of the sky.

scholarly journals High energy cosmic ray interactions and UHECR composition problem

2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Hadronic Interactions ◽  
High Energy Cosmic Rays ◽  
Cosmic Ray Interactions ◽  
Composition Problem

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.

scholarly journals Cosmic ray transport and anisotropies to high energies

2015 ◽  
Vol 2 ◽  
pp. 39-44 ◽  
Author(s):  
P. L. Biermann ◽  
L. I. Caramete ◽  
A. Meli ◽  
B. N. Nath ◽  
E.-S. Seo ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Wave Number ◽  
Ultra High Energy ◽  
Galactic Magnetic Field ◽  
Chemical Abundances ◽  
High Energy Cosmic Rays ◽  
High Energies ◽  
Isotropic Approximation ◽  
Galactic Cosmic Ray

Abstract. A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum k-5/3 at small scales λ = 2 π/k with k the wave-number, then a saturation spectrum k-1, and finally a shock-dominated spectrum k-2 mostly in the halo/wind outside the Cosmic Ray disk. In an isotropic approximation such a model is consistent with the Interstellar Medium (ISM) data. With this model we discuss the Galactic Cosmic Ray (GCR) spectrum, as well as the extragalactic Ultra High Energy Cosmic Rays (UHECRs), their chemical abundances and anisotropies. UHECRs may include a proton component from many radio galaxies integrated over vast distances, visible already below 3 EeV.

scholarly journals Composition and Galactic Confinement of Cosmic Rays

1971 ◽  
Vol 2 ◽  
pp. 740-756
Author(s):  
Maurice M. Shapiro
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Interstellar Space ◽  
Heavy Nuclei ◽  
High Energy Astrophysics ◽  
Transit Times ◽  
The Galaxy ◽  
Path Lengths

The ‘Galactic’ cosmic rays impinging on the Earth come from afar over tortuous paths, traveling for millions of years. These particles are the only known samples of matter that reach us from regions of space beyond the solar system. Their chemical and isotopic composition and their energy spectra provide clues to the nature of cosmic-ray sources, the properties of interstellar space, and the dynamics of the Galaxy. Various processes in high-energy astrophysics could be illuminated by a more complete understanding of the arriving cosmic rays, including the electrons and gamma rays.En route, some of theprimordialcosmic-ray nuclei have been transformed by collision with interstellar matter, and the composition is substantially modified by these collisions. A dramatic consequence of the transformations is the presence in the arriving ‘beam’ of considerable fluxes of purely secondary elements (Li, Be, B), i.e., species that are, in all probability, essentially absent at the sources. We shall here discuss mainly the composition of the arriving ‘heavy’ nuclei -those heavier than helium - and what they teach us about thesourcecomposition, the galactic confinement of the particles, their path lengths, and their transit times.

scholarly journals COLOR GLASS CONDENSATE IN BRANE MODELS OR DON'T ULTRA HIGH ENERGY COSMIC RAYS PROBE 1015eV SCALE?

2005 ◽  
Vol 20 (06) ◽  
pp. 419-440 ◽  
Author(s):  
HOURI ZIAEEPOUR
Keyword(s):  
Cosmic Rays ◽  
Extra Dimension ◽  
Cosmic Ray ◽  
High Energy ◽  
Effective Density ◽  
Color Glass ◽  
Color Glass Condensate ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Brane Models

In a previous work1 we have studied the propagation of relativistic particles in the bulk for some of the most popular brane models. Constraints have been put on the parameter space of these models by calculating the time delay due to propagation in the bulk of particles created during the interaction of Ultra High Energy Cosmic Rays (UHECRs) with protons in the terrestrial atmosphere. The question was, however, raised that probability of hard processes in which bulk modes can be produced is small and consequently, the tiny flux of UHECRs cannot constrain brane models. Here we use Color Glass Condensate (CGC) model to show that effects of extra dimensions are visible not only in hard processes when the incoming photon/parton hits a massive Kaluza–Klein mode but also through the modification of soft/semi-hard parton distribution. At classical level, for an observer in the CM frame of UHECR and atmospheric hadrons, color charge sources are contracted to a thin sheet with a width inversely proportional to the energy of the ultra energetic cosmic ray hadron and consequently they can see an extra dimension with comparable size. Due to QCD interaction, a short life swarm of partons is produced in front of the sheet and its partons can penetrate to the extra-dimension bulk. This reduces the effective density of partons on the brane or in a classical view creates a delay in the arrival of the most energetic particles if they are reflected back due to the warping of the bulk. In CGC approximation the density of swarm at different distances from the classical sheet can be related and therefore it is possible (at least formally) to determine the relative fraction of partons in the bulk and on the brane at different scales. Results of this work are also relevant to the test of brane models in hadron colliders like LHC.

scholarly journals CODALEMA: A COSMIC RAY AIR SHOWER RADIO DETECTION EXPERIMENT

2006 ◽  
Vol 21 (supp01) ◽  
pp. 192-196 ◽  
Author(s):  
D. ARDOUIN ◽  
A. BELLETOILE ◽  
D. CHARRIER ◽  
R. DALLIER ◽  
L. DENIS ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Air Showers ◽  
Detection Experiment ◽  
Transient Signals ◽  
High Energy Cosmic Rays ◽  
Air Shower ◽  
Radio Detection

The CODALEMA experimental device currently detects and characterizes the radio contribution of cosmic ray air showers : arrival directions and electric field topologies of radio transient signals associated to cosmic rays are extracted from the antenna signals. The measured rate, about 1 event per day, corresponds to an energy threshold around 5.1016eV. These results allow to determine the perspectives offered by the present experimental design for radiodetection of Ultra High Energy Cosmic Rays at a larger scale.

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