scholarly journals The phosphorus/sulfur abundance ratio as a test of galactic cosmic-ray source models

2001 ◽  
Author(s):  
J. S. George
Keyword(s):  
Cosmic Ray ◽  
Abundance Ratio ◽  
Source Models ◽  
Galactic Cosmic Ray

Test of Galactic Cosmic-Ray Source Models

2001 ◽  
pp. 329-352 ◽  
Author(s):  
L. O’C. Drury ◽  
D. E. Ellison ◽  
F. A. Aharonian ◽  
E. Berezhko ◽  
A. Bykov ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Source Models ◽  
Galactic Cosmic Ray

Distinguishing galactic cosmic-ray source models with first ionization potential and volatility

2001 ◽  
Vol 27 (4) ◽  
pp. 779-784 ◽  
Author(s):  
J.S. George ◽  
M.E. Wiedenbeck ◽  
A.F. Barghouty ◽  
W.R. Binns ◽  
E.R. Christian ◽  
...  
Keyword(s):  
Ionization Potential ◽  
Cosmic Ray ◽  
Source Models ◽  
Galactic Cosmic Ray ◽  
First Ionization Potential

A long term change in the cosmic ray composition?: studies on fossil cosmic ray tracks in lunar samples

1977 ◽  
Vol 285 (1327) ◽  
pp. 593-599 ◽  
Keyword(s):  
Composition Studies ◽  
Cosmic Ray ◽  
Lunar Soil ◽  
Abundance Ratio ◽  
Group V ◽  
Term Change ◽  
Lunar Samples ◽  
Lunar Rocks ◽  
Galactic Cosmic Ray

The etching techniques for the identification of very heavy cosmic ray ions from their etchable tracks in mineral track detectors are described and the results so far obtained for the ancient galactic cosmic ray Cr group (V + Cr + Mn) to Fe abundance ratio are presented. It was found that the etchable radiation damage of fossil cosmic ray tracks has probably only been slightly affected by annealing processes. The track data obtained on pyroxenes of different lunar rocks and on pyroxenes and feldspars, i.e. detectors of different track retaining characteristics, yielded consistent results. From this measurements, an ancient Cr group to Fe ratio of approximately 0.7- 0.8 was deduced. In comparison with the present day galactic cosmic ray composition, this ratio is enhanced by a factor of about two. From the track data obtained in different lunar soil samples it was concluded that a variation in the Gr group to Fe ratio between 0.4- 0.8 exists. Both results indicate, that either a long term change in the cosmic ray composition has taken place or the interpretation of track data is much more complicated than assumed.

scholarly journals The theory of cosmic ray scattering on pre-existing MHD modes meets data

2021 ◽  
Vol 502 (4) ◽  
pp. 5821-5838
Author(s):  
Ottavio Fornieri ◽  
Daniele Gaggero ◽  
Silvio Sergio Cerri ◽  
Pedro De La Torre Luque ◽  
Stefano Gabici
Keyword(s):  
Diffusion Coefficients ◽  
Galactic Halo ◽  
Dominant Role ◽  
Cosmic Ray ◽  
High Energy ◽  
Scattering Rate ◽  
Equilibrium Spectrum ◽  
Galactic Cosmic Ray ◽  
Comprehensive Study ◽  
Ray Scattering

ABSTRACT We present a comprehensive study about the phenomenological implications of the theory describing Galactic cosmic ray scattering on to magnetosonic and Alfvénic fluctuations in the GeV−PeV domain. We compute a set of diffusion coefficients from first principles, for different values of the Alfvénic Mach number and other relevant parameters associated with both the Galactic halo and the extended disc, taking into account the different damping mechanisms of turbulent fluctuations acting in these environments. We confirm that the scattering rate associated with Alfvénic turbulence is highly suppressed if the anisotropy of the cascade is taken into account. On the other hand, we highlight that magnetosonic modes play a dominant role in Galactic confinement of cosmic rays up to PeV energies. We implement the diffusion coefficients in the numerical framework of the dragon code, and simulate the equilibrium spectrum of different primary and secondary cosmic ray species. We show that, for reasonable choices of the parameters under consideration, all primary and secondary fluxes at high energy (above a rigidity of $\simeq 200 \, \mathrm{GV}$) are correctly reproduced within our framework, in both normalization and slope.

A comparison of catalogues of Forbush decreases identified from individual and a network of neutron monitors: a critical perspective

2021 ◽  
Vol 503 (4) ◽  
pp. 5675-5691
Author(s):  
O Okike ◽  
J A Alhassan ◽  
E U Iyida ◽  
A E Chukwude
Keyword(s):  
Cosmic Ray ◽  
Radiowave Propagation ◽  
Current Work ◽  
Survey Method ◽  
Critical Perspective ◽  
Short Term ◽  
Forbush Decreases ◽  
Academy Of Sciences ◽  
Galactic Cosmic Ray ◽  
Monitor Data

ABSTRACT Short-term rapid depressions in Galactic cosmic ray (GCR) flux, historically referred to as Forbush decreases (FDs), have long been recognized as important events in the observation of cosmic ray (CR) activity. Although theories and empirical results on the causes, characteristics, and varieties of FDs have been well established, detection of FDs, from either isolated detectors' or arrays of neutron monitor data, remains a subject of interest. Efforts to create large catalogues of FDs began in the 1990s and have continued to the present. In an attempt to test some of the proposed CR theories, several analyses have been conducted based on the available lists. Nevertheless, the results obtained depend on the FD catalogues used. This suggests a need for an examination of consistency between FD catalogues. This is the aim of the present study. Some existing lists of FDs, as well as FD catalogues developed in the current work, were compared, with an emphasis on the FD catalogues selected by the global survey method (GSM). The Forbush effects and interplanetary disturbances database (FEID), created by the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation Russian Academy of Sciences (IZMIRAN), is the only available comprehensive and up to date FD catalogue. While there are significant disparities between the IZMIRAN FD and other event lists, there is a beautiful agreement between FDs identified in the current work and those in the FEID. This may be a pointer to the efficiency of the GSM and the automated approach to FD event detection presented here.

scholarly journals Galactic cosmic ray origin sites: Supernova remnants and superbubbles

2012 ◽  
Author(s):  
A. M. Bykov ◽  
D. C. Ellison ◽  
P. E. Gladilin ◽  
S. M. Osipov
Keyword(s):  
Supernova Remnants ◽  
Cosmic Ray ◽  
Galactic Cosmic Ray
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