Low-freq. radio emission M dwarfs spectra

The M dwarf nature of our sources has been confirmed with optical spectroscopy performed using HET/LRS2 and Subaru/FOCAS, and their radio flux densities are within the range of 0.5-1.0mJy at 144MHz. Considering the radio-optical source separation and source densities of the parent catalogues, we suggest that it is statistically probable the M dwarfs are associated with the radio emission.

However, it remains plausible that for some of the sources the radio emission originates from an optically faint and red galaxy hiding behind the M dwarf. The isotropic radio luminosities (~10^17-18^erg/s/Hz) of the M dwarfs suggest that if the association is real, the radio emission is likely driven by a coherent emission process produced via plasma or electron-cyclotron maser instability processes, which is potentially caused by binary interaction.