Kinematics of CMEs and associated shock waves as deduced from LASCO data: comparative analysis

TL;DR

This study analyzes the kinematics of coronal mass ejections (CMEs) and their associated shock waves using LASCO data, revealing that shocks generally move faster than CME bodies and the gap widens with distance, especially for halo CMEs.

Contribution

It provides a comparative analysis of CME and shock wave kinematics in 3D space, highlighting differences based on CME type and source location.

Findings

Shock velocity exceeds CME body velocity in all cases.

The distance between CME and shock increases with propagation distance.

Halo CMEs exhibit larger CME-shock gaps and velocity differences.

Abstract

From data by LASCO C2 and C3 coronagraphs, depending on time (distance), we have determined positions and velocities of the front for fast limb CMEs' body with their sources near the limb, and for the body of halo-type CME with the sources near the solar disk center. These characteristics of CME body are compared to similar kinematic characteristics obtained for CME body-associated shock waves (shocks). For the body of halo-type CME with the sources near the solar disk center and associated shocks, we determined and compared their kinematic characteristics in 3D space. It has been shown that for all the considered CME groups, the shock velocity is higher than the CME body velocity, both velocities decrease as the mass ejection moves. As this takes place, the distance between CME body and shock grows. On average, distance from CME body to shock, and velocity difference of these structures is greater for a halo CME, and even greater for a model CME in 3D.