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Energy Cosmic Rays (energy + cosmic_ray)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

On active galactic nuclei as sources of ultra-high energy cosmic rays

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY: LETTERS (ELECTRONIC), Issue 1 2008
M. R. George
ABSTRACT We measure the correlation between sky coordinates of the Swift Burst Alert Telescope (BAT) catalogue of active galactic nuclei (AGN) with the arrival directions of the highest energy cosmic rays detected by the Auger Observatory. The statistically complete, hard X-ray catalogue helps to distinguish between AGN and other source candidates that follow the distribution of local large-scale structure. The positions of the full catalogue are marginally uncorrelated with the cosmic ray arrival directions, but when weighted by their hard X-ray flux, AGN within 100 Mpc are correlated at a significance level of 98 per cent. This correlation sharply decreases for sources beyond ,100 Mpc, suggestive of a GZK suppression. We discuss the implications for determining the mechanism that accelerates particles to these extreme energies in excess of 1019 eV. [source]

Tidal dynamics of relativistic flows near black holes

ANNALEN DER PHYSIK, Issue 5 2005
C. Chicone
Abstract We point out novel consequences of general relativity involving tidal dynamics of ultrarelativistic relative motion. Specifically, we use the generalized Jacobi equation and its extension to study the force-free dynamics of relativistic flows near a massive rotating source. We show that along the rotation axis of the gravitational source, relativistic tidal effects strongly decelerate an initially ultrarelativistic flow with respect to the ambient medium, contrary to Newtonian expectations. Moreover, an initially ultrarelativistic flow perpendicular to the axis of rotation is strongly accelerated by the relativistic tidal forces. The astrophysical implications of these results for jets and ultrahigh energy cosmic rays are briefly mentioned. [source]

Catching the highest energy cosmic rays

ASTRONOMY & GEOPHYSICS, Issue 2 2009
Alan A Watson FRS
First page of article [source]