The anisotropy of EHE cosmic rays

Lee, A A; Clay, R. W.

doi:10.1088/0954-3899/21/12/010

Cited by 21 publications

(27 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Even if a turbulent magnetic halo field is assumed in addition to the regular and turbulent galactic magnetic fields along the disc, a strong anisotropy is expected if cosmic rays around 10 19 eV are protons. A prediction of the anisotropy in harmonic analysis in right ascension at the latitude of Haverah Park has been derived (Lee and Clay, 1995): its amplitude is ϳ50-90% from the direction of 0 hour in right ascension, much larger than the observed anisotropy (Sec. VI.B.1).…”

Section: B Propagation In the Galaxymentioning

confidence: 97%

“…Monte Carlo simulations by Lee and Clay (1995) and Giller et al (1994) predict 10-20% amplitudes under assumptions of a cylindrical halo above and below the galactic disc, in which the source distribution is uniform.…”

Section: Comparison With the Spectrum In The Lower-energy Regionmentioning

confidence: 99%

“…The propagation of cosmic rays in the galactic magnetic field with turbulent magnetic fields of various length scales (ϳ50-150 pc) has been investigated in discussions of wide-angle anisotropy by Karakula et al (1972), Berezinsky et al (1991), and Lee and Clay (1995). These authors followed the trajectories of antiprotons emitted isotropically from the earth.…”

Section: B Propagation In the Galaxymentioning

confidence: 99%

See 2 more Smart Citations

Observations and implications of the ultrahigh-energy cosmic rays

2000

View full text Add to dashboard Cite

The authors define ''ultrahigh-energy cosmic rays'' (UHECRs) as those cosmic rays with energies above 10 18 eV. It had been anticipated that there would be a cutoff in the energy spectrum of primary cosmic rays around 6ϫ10 19 eV induced by the interaction of the particles with the 2.7-K primordial photons. However, recent experimental data have established that particles exist with energies greatly exceeding this. It follows that the sources of such particles are probably nearby, on a cosmological scale. However, although the trajectories of such energetic particles through the galactic and intergalactic magnetic fields may be nearly rectilinear, no astronomical sources have as yet been identified. This is the enigma of the highest-energy cosmic rays. The paper reviews the history of research in this energy regime and critically assesses the observational results on the energy spectrum, arrival directions, and composition of the primary cosmic rays based on observations made by six experiments. The detection methods currently available are described. Special techniques have been developed as particles of 10 20 eV or higher occur at a rate of only about 1 per km 2 per century. Errors in measurement are given particular attention. The authors also review the theoretical predictions for a number of candidate sources of cosmic rays beyond the predicted cutoff. Finally, the four major projects planned to address the question of the origin of UHECRs are briefly described. CONTENTS

show abstract

Section: B Propagation In the Galaxymentioning

confidence: 97%

Section: Comparison With the Spectrum In The Lower-energy Regionmentioning

confidence: 99%

Section: B Propagation In the Galaxymentioning

confidence: 99%

See 1 more Smart Citation

Observations and implications of the ultrahigh-energy cosmic rays

2000

View full text Add to dashboard Cite

show abstract

“…The flux associated with the AGASA source alone is not well defined, due to the analysis procedures, but a comparison with the AGASA energy spectrum suggests that there are significant remaining Galactic sources at 10 18 eV. The remaining directions show no clear anisotropy and we are left with the problem addressed by Lee & Clay (1995) in a rather stronger form. This is that, despite the likelihood that there are only a few active cosmic ray sources at 10 18 eV, the Galactic cosmic ray anisotropy is very low.…”

Section: Discussionmentioning

confidence: 89%

“…We have examined the propagation of cosmic rays through turbulent magnetic fields as described by Lee & Clay (1995) and Clay (2000). We used a random magnetic field with a turbulent Kolmogorov spectrum and a maximum scale size of 100 pc.…”

Section: Propagation Through Turbulent Magnetic Fieldsmentioning

confidence: 99%

Galactic Structure and the Cosmic Ray Anisotropy at 10¹⁸eV

Clay

2001

Publ. – Astron. Soc. Aust

View full text Add to dashboard Cite

Cosmic ray arrival directions at energies a little over 1018 eV have been reported to show an excess from directions close to that of the Galactic centre. That result was originally presented by the AGASA group and was later strengthened by an analysis of SUGAR cosmic ray data. We discuss here a second feature of the AGASA data, a deficit in roughly the Galactic anticentre direction.We interpret this as a result of cosmic ray diffusion past us. We find that the most straightforward interpretation of the data then requires that a strong magnetic field exists out of the plane of our Galaxy to distances of at least several kiloparsecs.

show abstract

The high energy cosmic ray spectrum from relic particle decay

2002

View full text Add to dashboard Cite

It has been speculated that the recently detected ultra-high energy cosmic rays may originate from the decays of relic particles with mass of order $10^{12}$ GeV clustered in the halo of our Galaxy. This hypothesis can be tested through forthcoming measurements of the spectra of both high energy cosmic nucleons and neutrinos, which are determined in this model by the physics of QCD fragmentation, with no astrophysical uncertainties. We evolve fragmentation spectra measured at LEP energies up to the scale of the decaying particle mass by numerical solution of the DGLAP equations. This enables incorporation of the effects of supersymmetry on the development of the cascade and we also allow for decays into many-particle states. The calculated spectral shape agrees well with present cosmic ray data beyond the Greisen-Zatsepin-Kuzmin energy.Comment: 30 pages (revtex), 12 figures (eps); Small revisions; Accepted for publicatio

show abstract

The anisotropy of EHE cosmic rays

Cited by 21 publications

References 30 publications

Observations and implications of the ultrahigh-energy cosmic rays

Observations and implications of the ultrahigh-energy cosmic rays

Galactic Structure and the Cosmic Ray Anisotropy at 10¹⁸eV

The high energy cosmic ray spectrum from relic particle decay

Contact Info

Product

Resources

About

The anisotropy of EHE cosmic rays

Cited by 21 publications

References 30 publications

Observations and implications of the ultrahigh-energy cosmic rays

Observations and implications of the ultrahigh-energy cosmic rays

Galactic Structure and the Cosmic Ray Anisotropy at 1018eV

The high energy cosmic ray spectrum from relic particle decay

Contact Info

Product

Resources

About

Galactic Structure and the Cosmic Ray Anisotropy at 10¹⁸eV