Relative velocity vectors for member candidates in Coma Ber and group-X. (a) The red vectors represent the relative velocity of member candidates of Coma Ber to its mean motion, (U, V, W) = (8.6, 226.6, 6.8) km s⁻¹ on the X–Y plane, and the blue vectors represent the relative velocity of member candidates of group-X to its mean motion, (U, V, W) = (7.7, 223.2, 5.8) km s⁻¹. Only stars within 1σ from the mean value are shown in (a) and (b), with velocity ranges from 0.1 to 2.0 km s⁻¹ for Coma Ber and 0.4 to 3.1 km s⁻¹ for group-X. The plus sign shows the center of each group (Section 4.3). The purple circle denotes the tidal radius of Coma Ber. (b) The same relative velocity distribution of Coma Ber and group-X on Z–Y plane. (c) The relative velocity distributions of Coma Ber and group-X to the mean motion of Coma Ber on the X–Y plane. (d) The same relative velocity distribution of Coma Ber and group-X on Z–Y plane. The vector length and color coding are scaled to the relative velocity. An integrated orbit the same as that in Figure 4 is shown as well.