The influence of the supersonic transverse flow of atoms on properties of a high-current, low-pressure discharge is investigated for the first time. Such a discharge is used in particular, in powerful CW ion lasers. The theory of the discharge of this type is suggested. The equations for the electric field and the density profiles of atoms and ions in plasma were obtained and solved analytically. The flow velocity, temperatures and radial intensity distributions of the spontaneous emission of ArI and ArII were measured. It was shown both theoretically and experimentally that, unlike the discharge in a motionless gas, the distributions became asymmetric. Moreover, the ion density maximum was displaced with respect to the discharge axis opposite the flow, while in a high-pressure discharge the charged particles are carried away with the flow.