NOAA region 2673 produced a X9.3 flare on September 6 2017, peaking at 12:02 UT. It was accompanied by an intense and complex radio event displaying a low frequency type II burst, and a type IV burst spanning the entire frequency range covered by the ARCAS and HSRS spectrometers in Humain.
A lot of fine structures (spikes, zebra bursts. etc...) can be seen in the dynamic spectra shown here.
A preliminary analysis of light curves (see below) at certain frequencies shows an intensity of about 25 dB above the quiet sun level near the peak of the flare (12:02 UT), above 1 GHz. Our colleagues from the Time-Iono-GNSS group detected the event in their Solar Radio Burst warning system for GNSS.
Almost two hours after the Soft X-ray event, the radio type IV burst is still in progress, as shown by the spectra below taken from the real time observation page.
