
TY  - JOUR
A1  - Lampard, R 
A1  - Dawson, BR 
A1  - Clay, RW 
T1  - Limits on source distances for the most energetic cosmic rays
JF  - Publications of the Astronomical Society of Australia
JO  - Publ. Astron. Soc.  Aust.
Y1  - 1997
VL  - 14
IS  - 3
SP  - 258
EP  - 264
KW  - 
UR  - https://doi.org/10.1071/AS97258 
N2  - The propagation of the highest energy cosmic rays through the 2.7 K microwave background is considered. Photo-pion production interactions cause energy losses for primary cosmic ray protons which result in significant energy degradation over intergalactic distances. The process of energy loss is discussed and an estimate is made of the average distances travelled for observed cosmic rays with a range of energies, assuming a power law source spectrum. At energies over 10^20^ eV, the average distances travelled are a few tens of megaparsecs, limiting possible sources to the volume dominated by the supergalactic plane. 
ER  -

