Large‐Scale Activities Associated with the 2003 October 29 X10 Flare

Abstract

We present a multiwavelength study focusing on the large-scale activities associated with the 2003 October 29 X10 flare and a halo CME. This event was strong enough to clearly show several large-scale activities, such as remote brightenings, Moreton waves at Hα off-bands, and type II radio bursts, which offers an excellent opportunity to clarify the relationship among them. The remote brightenings were found near two coronal holes more than 2 × 105 km from the main flare in eastern and southern directions, respectively. Coronal dimmings were seen at the locus of the remote brightenings right after the flare at both EUV and soft X-ray wavelengths. The Moreton waves propagated both northeastward and southward, toward the aforementioned remote regions, at speeds of approximately 1100 and 1900 km s-1, respectively. Our analyses show that the Moreton waves, the type II radio bursts, and the CME started almost simultaneously, but were not cotemporal with the remote brightenings. The remote brightenings are rather consistent with the flare hard X-ray emissions within the active region, although they have much smaller scales. We therefore conclude that the two remote brightening regions were magnetically connected to the flaring active region, and that the remote brightenings, as well as all other activities, were due to the interaction of an erupting flux rope at the core of the flare with magnetic field overlying the region. In this scenario, the large overlying loops should open to allow the flare activity underneath them, which points to a picture similar to the magnetic break-out process in such a large scale.