Events in this spectral region are characterized by a quantity called the dispersion measure, which had a remarkably high value of 375 for an event named after Duncan Lorimer. In 2006, ARCADE detected noise in this spectral region that was sixfold higher than expected for still-unknown reasons, which has been dubbed a “space roar.” The CHIME telescope has predominantly been used to detect mysterious, extragalactic events in this region lasting milliseconds; those are (*) "fast (10[1])bursts" in this region. Radiation in this region of the spectrum is not imaged using CCDs, but rather reconstructed from their wave nature using techniques like aperture synthesis and VLBI. The detection of radiation in this region of the spectrum by Jocelyn Bell led to the discovery of pulsars. For 10 points, name this lowest-energy region of the electromagnetic spectrum. ■END■