Radio bursts associated with the 22 September 2011 flare and CME. Panel a: Type II and continuum emission observed by the ARTEMIS spectrograph at frequencies < 200 MHz. Panel b: Type IV bursts observed by the e-CALLISTO BLEIEN dish at frequencies 200–400 MHz and at frequencies (> 600 MHz). Panel c: microwave burst observed by Ondrejov Spectrograph (0.8–1 GHz) and Phoenix3 spectrometer (1–2 GHz). Panel d: GOES X-ray light curve of the X1.4 flare on 22 September 2011. The green dashed line denotes the CME onset, which is defined as the time when the CME expands beyond a distance of 1.2 R_⊙, and the purple line denotes the peak time of the flare.