Radio and X-Ray Signatures of Magnetic Reconnection behind an Ejected Flux Rope
Résumé
We present a detailed study of a complex solar event observed on 2002 June 2. Joint imaging EUV, X-ray, and multiwavelength radio observations allow us to trace the development of the magnetic structure involved in this solar event up to a radial distance of the order of 2 Rsolar. The event involves type II, III, and IV bursts. The type IV burst is formed by two sources: a fast-moving one (M) and a ``quasi-stationary'' one (S). The time coincidence in the flux peaks of these radio sources and the underlying hard X-ray sources implies a causal link. In the first part of our paper we provide a summary of the observations without reference to any coronal mass ejection (CME) model. The experimental results impose strong constraints on the physical processes. In the second part of our paper, we find that a model with an erupting twisted flux rope, with the formation of a current sheet behind, best relates the different observations in a coherent physical evolution (even if there is no direct evidence of the twisted flux rope). Our results show that multiwavelength radio imaging represents a powerful tool to trace the dynamical evolution of the reconnecting current sheet behind ejected flux ropes (in between sources M and S) and over an altitude range not accessible by X-ray observations.