Hα image of the HH 83 outflow system integrated over all velocity channels, with superposed PM vectors for the jet knots and the counterflow (left panel). Bottom right panel: grid of Hα profiles in the NW bow. The significant split of profiles for the high- and low-velocity components is obvious (the absolute velocity values decrease to the right). Separate images of the low-velocity (contours) and high-velocity components (grey scale) basedon the intensities obtained by the Gaussian fitting of the profiles of both components are presented in the top right panel. The corresponding PM vectors also are shown.