Extreme narrow-band radio emission associated with a moderate X-ray flare

Nicole Vilmer, LESIA Paris Observatory

Very strong narrow-band radio emissions (>10 4 sfu) are sometimes observed in the 1GHz-2GHz range in association with moderate X-ray class flares. One of these extreme events (with a flux >105 sfu) has been shown recently to be responsible for a disturbance of aeronautical radio navigation (see Marqué et al., 2018). We shall present in this talk another example of a GOES M-class flare (18 November 2003) producing an episode (around 10 minutes) of very strong (>10 4 sfu) narrow-band emission around 1GHz. We will present combined observations from RHESSI, the Radio Solar Telescope Network (RSTN) and the PHOENIX spectrograph to investigate the possible emission mechanisms leading to the extreme narrow-band emissions. We shall also examine the conditions in the flaring active region which could lead to these strong radio enhancements.