On the origin of ultrahigh energy cosmic rays On the origin of ultrahigh energy cosmic rays Martin Lemoine Martin Lemoine Institut d’Astrophysique de Paris Institut d’Astrophysique de Paris CNRS, Université Pierre & Marie Curie CNRS, Université Pierre & Marie Curie Nagano & Watson 00 very small flux at UHE: ∼1/km 2 /century at 10 20 eV knee second knee ? ankle knee ? Galactic CR