The subject of ‘cosmic rays’ is one that embraces a vast range of
particle and photon energies and is an ideal one for examining ‘Physics
and the Cosmos’. In the present work we examine the twin ...problems of the
origin of cosmic rays of both low and very high energies and find that they
are related by studies of the Magellanic Clouds. This remarkable result comes
from the hypothesis that there is a Giant Halo surrounding the Galaxy, support
coming from Magellanic Cloud observations. Also examined is the flux of
extragalactic gamma rays and its relevance to the question of the asymmetry
between matter and anti-matter in the Universe.
Evidence for a local 'Single Source' of cosmic rays is amassing by way of the recent precise measurements of various cosmic ray energy spectra from the AMS-02 instrument. To observations of ...individual cosmic ray nuclei, electrons, positrons and antiprotons must now be added the determination of the boron-to-carbon ratio and the energy spectrum of lithium to 2000 GV with high precision. Our analysis leads us to claim that, with certain assumptions about the propagation in the Galaxy, the results confirm our arguments regarding the presence of a local single source, perhaps, a supernova remnant (SNR). An attempt is made to determine some of the properties of this SNR and its progenitor star.
We have used recently published data from the Pierre Auger Observatory and the Telescope Array Project to conclude some inferences concerning the origin and composition of ultra high-energy cosmic ...rays (UHECR). We advocate for model the UHECR flux as a combination of the Galactic and Extragalactic components exchanging the dominant role at the famous feature of the energy spectrum called 'the ankle'. We put a special emphasis on the individual experiment energy resolution and possible biases it introduces. We have eventually combined the data from both big experiments to the one 'world average' UHECR spectrum and we used it, supported by the analysis of the distribution of the Extensive Air Shower (EAS) development maximum depth to find the UHECR mass composition of both: Galactic and Extragalactic components. We studied the dependence of the on mass composition on the cosmic ray source distribution in space. We present results for some models existing in the literature. We found the evidence of the deficit of Extragalactic sources in the vicinity of the Galaxy of the the UHECR, what is in concordance with the small scale anisotropy analysis results.
Puzzles of the cosmic ray anisotropy Erlykin, Anatoly; Machavariani, Svetlana; Wolfendale, Arnold
arXiv (Cornell University),
02/2019
Paper, Journal Article
Odprti dostop
We discuss three of the known puzzles of the cosmic ray anisotropy in the PeV and sub-PeV energy region. They are: (1) the so called inverse anisotropy, (2) the irregularity in the energy dependence ...of the amplitude and phase of the first harmonic and (3) the contribution of the single source.
In view of the fact that the AMS-02 instrument has recently been used to make preliminary observations of the ratio of the antiprotons (\-{P}) to protons (P) in the primary cosmic radiation we have ...returned to our idea of signatures of a local recent supernova. We find that at the present level of accuracy there is no inconsistency between our predictions for the \-{P}/P ratio to some hundreds of GeV using the preliminary observations.
The attribution of part of global warming to changes in the total solar irradiance (TSI) is an important topic which is not, yet, fully understood. Here, we examine the TSI induced temperature (T) ...changes on a variety of time scales, from one day to centuries and beyond, using a variety of assumptions. Also considered is the latitude variation of the T-TSI correlations, where it appears that over most of the globe there is a small increase in the sensitivity of temperature to TSI in time. It is found that the mean global sensitivity (alpha)measured in K(Wm-2)-1 varies from about 0.003 for 1 day, via 0.05 for 11-years to about 0.2 for decades to centuries. We conclude that mean global temperature changes related to TSI are not significant from 1975 onwards. Before 1975, when anthropogenic gases were less important, many of the temperature changes can be attributed to TSI variations. Over much longer periods of time, from Kyear to Myear, the TSI changes are more efficient still, the sensitivity alpha increasing ro about 0.5. Since 1975 the changes in mean global temperature are not due to TSI changes, but rather to the increasing atmospheric CO2 content.
Risks in space WOLFENDALE, ARNOLD
European review (Chichester, England),
02/2003, Letnik:
11, Številka:
1
Journal Article
Recenzirano
The human species is beset by ‘risks’; one of which is related to its exposed position on the Earth as it travels through cosmic space. An examination is made of the major risks – those associated ...with cometary impact, with solar emissions and with the explosions of nearby stars. Estimates are given of the risks associated with trying to avoid the effect of these phenomena. Not surprisingly it is concluded that more work is necessary.
The existence of the cosmic ray Halo in our Galaxy has been discussed for more than half a century. If it is real it could help to explain some puzzling features of the cosmic ray flux: its small ...radial gradient, nearly perfect isotropy and the low level of the fine structure in the energy spectra of the various particles. All these features could be understood if: (a) the Halo has a big size (b) cosmic rays in the Halo have a unform spatial distribution and (c) the cosmic ray density in the Halo is comparable or even higher than that in the Galactic Disk. The main topic of the paper concerns the present status of the anisotropy and a model for its formation. In our model the extremely small amplitude of the dipole anisotropy is due to the dilution of the anisotropy in the Disk by the dominating isotropic cosmic rays from the Halo. Some minor deviations from complete isotropy in the sub-PeV and PeV energy regions point out to the possible contribution of the Single Source with the phase of its first harmonic opposite to the phase produced by the Disk.
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