Substructures in the DG Tau B redshifted CO outflow. Left panels: ¹²CO channel maps at selected line-of-sight velocities. The white dashed line traces the θ = 17° outer limiting cone of the inner outflow as defined by DV20. Right panels: transverse PV diagrams across the flow averaged over a slice of ∆Z = 0.2″. Black dotted lines indicate the outer limits of the conical outflow at the specified height. The triangle (a) and the two circle symbols (c and d) highlight the on-axis height of one arch and two different cusps, respectively. The square symbol (b) is located in the extended outer flow. The symbols are represented both on the channel maps and PV diagrams.