Context. The origin of coronal type-II radio bursts and of theirband-splitting are still not fully understood. Aims. To make progress insolving this problem on the basis of one extremely well observed solar eruptiveevent. Methods. The relative dynamics of multi-thermal eruptive plasmas,observed in detail by the SDO/AIA and of the harmonic type-II burst sources,observed by the NRH at ten frequencies from 445 to 151 MHz, is studied for thepartially behind the limb event on 3 November 2010. Special attention is givento the band-splitting of the burst. Analysis is supplemented by investigationof coronal hard X-ray (HXR) sources observed by the RHESSI. Results. It isfound that the flare impulsive phase was accompanied by the formation of adouble coronal HXR source, whose upper part coincided with the hot (T~10 MK)eruptive plasma blob. The leading edge (LE) of the eruptive plasmas (T~1-2 MK)moved upward from the flare region with the speed of v=900-1400 km/s. The typeII burst source initially appeared just above the LE apex and moved with thesame speed and in the same direction. After about 20 s it started to move abouttwice faster, but still in the same direction. At any given moment the lowfrequency component (LFC) source of the splitted type-II burst was situatedabove the high frequency component (HFC) source, which in turn was situatedabove the LE. It is also found that at a given frequency the HFC source waslocated slightly closer to the photosphere than the LFC source. Conclusions.The shock wave, which could be responsible for the observed type-II radioburst, was initially driven by the multi-temperature eruptive plasmas, butlater transformed to a freely propagating blast shock wave. The most preferableinterpretation of the type-II burst splitting is that its LFC was emitted fromthe upstream region of the shock, whereas the HFC - from the downstream region.
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