标题:Three-dimensional reconstruction of CME-driven shock–streamer interaction from radio and EUV observations: a different take on the diagnostics of coronal magnetic fields
摘要:On 2014 October 30, a band-splitted typeIIradio burst associated with a coronal mass ejection (CME) observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) occurred over the southeast limb of the Sun. The fast expansion in all directions of the plasma front acted as a piston and drove a spherical fast shock ahead of it, whose outward progression was traced by simultaneous images obtained with the Nançay Radioheliograph (NRH). The geometry of the CME/shock event was recovered through 3D modeling, given the absence of concomitant stereoscopic observations, and assuming that the band-splitted typeIIburst was emitted at the intersection of the shock surface with two adjacent low-Alfvén speed coronal streamers. From the derived spatiotemporal evolution of the standoff distance between shock and CME leading edge, we were finally able to infer the magnetic field strengthBin the inner corona. A simple radial profile of the formB(r) = (12.6 ± 2.5)r−4nicely fits our results, together with previous estimates, in the ranger = 1.1−2.0R⊙.
关键词:enshock wavesSun: activitySun: coronaSun: coronal mass ejections (CMEs)Sun: radio radiation