Source Region of the Decameter - Hectometric Type II Radio Burst: Shock - Streamer Interaction Region

TL;DR

This study investigates the origins of decameter-hectometric type II radio bursts, revealing they originate from shock-streamer interaction regions where shocks are significantly enhanced, based on combined imaging and spectral data.

Contribution

It identifies the specific source regions of D-H type IIs as shock-streamer interaction zones, providing new insights into their generation mechanism.

Findings

Sources are located in shock-streamer interaction regions.

Shocks are significantly enhanced in these interaction regions.

Analysis based on two well-observed events confirms this origin.

Abstract

D-H type II radio bursts are widely thought to be caused by the coronal mass ejections (CMEs). However, it is still unclear where the exact source of the type IIs on the shock surface is. We identify the source regions of the decameter-hectometric (D--H) type IIs based on imaging observations from SOHO/LASCO and the radio dynamic spectrum from Wind/Waves. The analysis of two well-observed events suggests that the sources of these two events are located in the interaction regions between shocks and streamers, and that the shocks are enhanced significantly in these regions.