At what particle energy do extragalactic cosmic rays start to predominate?

Details At what particle energy do extragalactic cosmic rays start to predominate? At what particle energy do extragalactic cosmic rays start to predominate?

2004-10-26

arxiv.org/abs/astro-ph/0410624v1

J.Phys. G31 (2005) 255-264

Astronomy and Astrophysics

Astrophysics

Scientific paper

We have argued [J. Szabelski et al. (2002)] that the well-known `ankle' in the cosmic ray energy spectrum, at logE (eV) ~ 18.7-19.0, marks the transition from mainly Galactic sources at lower energies to mainly extragalactic above. Recently, however, there have been claims for lower transitional energies, specifically from logE (eV) ~ 17.0 [G. Thompson et al. (2004)] via 17.2-17.8 [V.S. Berezinsky et al. (2004)] to 18.0 [A.M. Hillas (2004)]. In our model the ankle arises naturally from the sum of simple power law-spectra with slopes differing by ~ 1.8; from differential slope -3.8 for Galactic particles (near logE = 19) to ~ -2.0 for extragalactic sources. In the other models, on the other hand, the ankle is intrinsic to the extragalactic component alone, and arises from the shape of the rate of energy loss versus energy for the (assumed) protons interacting with the cosmic microwave background (CMB). Our detailed analysis of the world's data on the ultra-high energy spectrum shows that taken together, or separately, the resulting mean sharpness of the ankle (second difference of the log(intensity*E^3) with respect to logE) is consistent with our `mixed' model. For explanation in terms of extragalactic particles alone, however, the ankle will be at the wrong energy - for reasonable production models and of insufficient magnitude if, as seems likely, there is still a significant fraction of heavy nuclei at the ankle energy.

Affiliated with

Also associated with

No associations

Rating

At what particle energy do extragalactic cosmic rays start to predominate? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with At what particle energy do extragalactic cosmic rays start to predominate?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and At what particle energy do extragalactic cosmic rays start to predominate? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-497803