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Narrowband bursts (spikes) appear on dynamic spectra from microwave todecametric frequencies. They are believed to be manifestations of small-scaleenergy release through magnetic reconnection. We study the position of thespike-like structures relative to the front of type-II bursts and their role inthe burst emission. We used high-sensitivity, low-noise dynamic spectraobtained with the acousto-optic analyzer (SAO) of the ARTEMIS-JLSradiospectrograph, in conjunction with images from the Nan\c{c}ayRadioheliograph (NRH) in order to study spike-like bursts near the front of atype-II radio burst during the November 3, 2003 extreme solar event. Thespike-like emission in the dynamic spectrum was enhanced by means ofhigh-pass-time filtering. We identified a number of spikes in the NRH images.Due to the lower temporal resolution of the NRH, multiple spikes detected inthe dynamic spectrum appeared as single structures in the images. These spikeshad an average size of ~200" and their observed brightness temperature was1.4-5.6x10^9K, providing a significant contribution to the emission of thetype-II burst front. At variance with a previous study on the type-IVassociated spikes, we found no systematic displacement between the spikeemission and the emission between spikes. At 327.0 MHz, the type II emissionwas located about 0.3 RSUN above the pre-existing continuum emission, which,was located 0.1 RSUN above the western limb. This study indicates that thespike-like chains aligned along the type II burst MHD shock front are not aperturbation of the type II emission, as in the case of type IV spikes, but amanifestation of the type II emission itself. The preponderance of thesechains, together with the lack of isolated structures or irregular clusters,points towards some form of small-scale magnetic reconnection, organized alongthe type-II propagating front.

High-resolution observations with ARTEMIS/JLS and the NRH: IV. Imaging spectroscopy of spike-like structures near the front of type-II bursts