NRH maps during selected periods of the event. Top left: Isointensity contours at half maximum during the type J burst at 11:55:03 UT (rectangle 1 in Fig. 4). Top right: Reverse-drifting burst near 11:55:30 UT (rectangle 2). Bottom left: Type J burst at 11:54:57 UT on the low-frequency side of the red spectral dividing line (rectangle 3). Bottom right: Image of the continuum source at 432 MHz (average 11:56:20–11:56:50 UT).