The Abundances of the Heavier Elements in the Cosmic Radiation

We review current work on the abundances of the ultraheavy elements in the cosmic radiation, those with Z≳30. Those abundances are compared with predictions based on propagation and fractionation of elemental abundances from various assumed sources of the cosmic rays. We find striking similarities between the solar system and the cosmic ray source abundances for those elements with 32≤Z≤60. For elements with Z≳60, there appears to be a substantial enhancement in the abundances of elements synthesized in the r‐process