Deflection of coronal rays by remote CMEs: shock wave or magnetic pressure?

TL;DR

This study investigates how coronal rays are deflected by remote CMEs, concluding that magnetic field influences, rather than shock waves, cause the observed deflections, with flux ropes altering surrounding magnetic structures.

Contribution

It provides evidence that magnetic pressure from flux ropes, not shock waves, causes coronal ray deflections during CME interactions.

Findings

Coronal ray deflections are not caused by shock waves.

Magnetic field influence from flux ropes explains ray deflections.

Retardation effects are important due to high flux rope speeds.

Abstract

We analyze five events of the interaction of coronal mass ejections (CMEs) with the remote coronal rays located up to 90^\circ away from the CME as observed by the SOHO/LASCO C2 coronagraph. Using sequences of SOHO/LASCO C2 images, we estimate the kink propagation in the coronal rays during their interaction with the corresponding CMEs ranging from 180 to 920 km/s within the interval of radial distances form 3 R. to 6 R. . We conclude that all studied events do not correspond to the expected pattern of shock wave propagation in the corona. Coronal ray deflection can be interpreted as the influence of the magnetic field of a moving flux rope related to a CME. The motion of a large-scale flux rope away from the Sun creates changes in the structure of surrounding field lines, which are similar to the kink propagation along coronal rays. The retardation of the potential should be taken into account since the flux rope moves at high speed comparable with the Alfven speed.