Example of a combined RPW-STIX plot for an event on 2021 May 9 (event ID 2105091412). The two upper panels show the measured radio flux in solar flux units (SFU) versus time and frequency measured by RPW/TNR and RPW/HFR. The bottom panel shows the X-ray flux in counts per 4 s as measured by STIX. Vertical dashed lines indicate the following times: electron SRTs derived from EPD data by TSA and VDA analysis, time of maximum X-ray flux from STIX, and the RPW onset times (details given in the main text) detected at 4 MHz or 1 MHz. Horizontal shaded areas at the top of the bottom panel indicate the uncertainties of the TSA and VDA SRTs following the same colour code.