Mon. Not. R. Astron. Soc., 380, L1-L5 (2007/September-1)
Revisiting the effect of nearby supernova remnants on local cosmic rays.
Abstract (from CDS):
In an earlier paper, the effect of the nearby known supernova remnants (SNRs) on the local cosmic rays (CRs) was studied, considering different possible forms of the particle injection time. The present work is a continuation of the previous work, but assumes a more realistic model of CR propagation in the Galaxy. The previous work assumed an unbounded three-dimensional diffusion region, whereas the present one considers a flat cylindrical disc bounded in both the radial and vertical directions. The study has found that the effect of the vertical halo boundary H on the local SNR contribution to the observed CR anisotropy is negligible as long as H ≳ 2kpc. Considering the values of the halo height H ≳ 2kpc obtained by different authors, the present work suggests that the study of the effect of local sources on the CR anisotropy can be carried out without having much information on H, and hence using the much simpler three-dimensional unbounded solution. Finally, the present work discusses the possibility of explaining the observed anisotropy below the knee by a single dominant source with properly chosen source parameters, and claims that the source may be an undetected old SNR with a characteristic age of ∼1.5x105yr located at a distance of ∼0.57kpc from the Sun.