Kinematics of CMEs and related shocks from LASCO data: Comparative analysis

We estimated the positions and velocities of the 10 fast limb CMEs with sources within the 30-degree from the limb and 10 fast halo CMEs with sources within the 30-degree from the solar disk center (central CMEs) using the LASCO-C2 and C3 images. The considered velocities, on which the results are based, include projection effects. We compared kinematic characteristics of the CME body with CME-related shocks whose linear projection velocities greater than 1500 km/s. For all the considered events: (1) the distance between the CME body and the related shock Delta R = (R-sh - R-b) increases with time; (2) the shock velocity V-sh is greater than the CME body velocity V-b; (3) the CME body acceleration modulus vertical bar a(b)vertical bar and the related shock acceleration modulus vertical bar a(sh)vertical bar differ. Herewith, in some cases, vertical bar a(sh)vertical bar > vertical bar a(b)vertical bar, and in other cases, on the contrary, vertical bar a(sh)vertical bar < vertical bar a(b)vertical bar (4) the difference in the velocities Delta V = (V-sh - V-b) grows with time for limb CMEs and decreases for central CMEs; (5) the variations of velocity-time profiles for the CME and shock are established to be equal: the velocities of both coronal structures either increase or decrease simultaneously. The following averaged values characterize the differences in the kinematics of the CME and shock: <Delta R > = 1.7 R-circle dot (R-circle dot is the solar radius), 'Delta V' = 250 km/s, 'V-sh/V-b' = 1.2, 'a(b)' = 65 m/s(2), 'a(sh)' = 70 m/s(2).