  The fragment separator FRS at GSI was used as an energy-loss spectrometer to
measure the longitudinal momentum distributions of {16,18}C fragments after
one-neutron removal reactions in {17,19}C impinging on a carbon target at about
910 MeV/u. The distributions in the projectile frames are characterized by a
FWHM of 141+-6 MeV/c for {16}C and 69+-3 MeV/c for {18}C. The results are
compared with experimental data obtained at lower energies and discussed within
existing theoretical models.
