X-ray emission of ultracool dwarfs across the radio-loud - radio-quiet boundary

Ongoing studies of magnetic activity at the end of the stellar mainsequencehave revealed an emerging dichotomy in the Xray and radio properties. Thehetero geneous properties of ultracool dwarfs (spectral type M7 and later)display either strong coronallike Xrays with low radio luminosities orpredominantly planetlike strong radio emissions with weak Xray luminosities.This bifurcation is likely driven by the properties of the magnetic field andthe stellar rotation. We will explicitly test this hypothesis by filling theparameter space with a TESSselected sample\\: The new TESS rotation period willbe complemented here with both radio and Xray data spanning the rotation periodthreshold across which the dichotomy appears. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]