We have measured the radio continuum emission of 396 early-type galaxies brighter than K = 9 , using 1.4 ~ { } { GHz } imagery from the NRAO VLA Sky Survey , Green Bank 300-ft Telescope and 64-m Parkes Radio Telescope .
For M _ { K } < -24 early-type galaxies , the distribution of radio powers at fixed absolute magnitude spans 4 orders of magnitude and the median radio power is proportional to K -band luminosity to the power 2.78 \pm 0.16 .
The measured flux densities of M _ { K } < -25.5 early-type galaxies are greater than zero in all cases .
It is thus highly likely that the most massive galaxies always host an active galactic nucleus or have recently undergone star formation .