Heavy nuclei at the end of the cosmic-ray spectrum? art. no. 103001

We provide an account of the possible acceleration of iron nuclei up to ene rgies similar to 300 EeV in the nearby, metally rich starburst galaxy NGC 2 53. It is suggested that particles can escape from the nuclear region with energies of similar to 10(15) eV and can then be reaccelerated at the termi nal shock of the galactic superwind generated by the starburst, avoiding th e photodisintegration expected if the nuclei were accelerated in the centra l region of high photon density. We have also made estimates of the expecte d arrival spectrum, which displays a strong dependence on the energy cutoff at the source. [S0556-2821(99)03020-9].