The line-of-sight velocities of NH₃ (J,K) = (1,1) (squares) and HC₃N J = 2−1 (triangles) at different radial distances along the main diagonal cuts (panels a) and b)) and in the perpendicular directions (panels c) and d)) of the molecular cores L1498 and L1512 shown in Fig. 1. The reference point in panels a) and b) is (Δα,Δδ) = (0′′,0′′), but it is (20′′,0′′) in panel c) and (−10′′,20′′) in d). The radial distances of the points from the circular sector with the central angle 0^o ≤ ψ < 180° are positive, whereas those from the sector 180° ≤ ψ < 360° are negative. The mean values of V_lsr are depicted for multiple observations at the same coordinate. The error bars show the 1σ uncertainties.