Detection of the 4th harmonica in the cyclotron radiation above the spot

    Radiation of the 4th harmonica of the gyro-frequency in the Solar corona above the spot was detected due to detailed spectroscopic observations at RATAN-600 with high-accuracy polarization measurements. The cyclotron radiation of the 4th harmonica is confirmed by detailed model calculations and the detected event is physically interpreted.
    For the first time, the observed manifestations of the cyclotron radiation in the 4th harmonica of the gyro-frequency were obtained. Model calculations confirmed the observed results. The significance of the result obtained is determined by the importance of measurements of the distribution of coronal magnetic fields in those areas of the solar atmosphere, where traditional methods based on the Zeeman and Hanle effects are inefficient due to high coronal temperatures.
    The result was presented at the "Solar and Solar-Terrestrial Physics 2017" XXI Russian Annual Conference on Solar Physics (October 09, 2017 - October 13, 2017) , Pulkovo Observatory.

Contacts:
Kaltman T.I.

Fig. 1. - Left-hand: spectra of the usual (o-mode) and unusual (e-mode) radiation for the active region of NOAA 11312. Here, the A-region is the entrance to the corona of the 4th gyro-harmonica, the B-region is the sharp increase in brightness at the entrance of the 3rd gyro-harmonica, and the C-region is the entrance to the corona of the 2nd gyro-harmonica. The measured estimates of the coronal magnetic field are shown. Right-hand: the part of the microwave spectrum in the e-mode corresponding to the 4th harmonica is shown on a large scale.