Our faintest radio sources are only factors of a few stronger than implied by the radio flux in the most intense starbursts [@collet14b], which is likely dominated by star formation [few$\times 10^{25}$ W Hz$^{-1}$, e.g., @barger14], whereas our most luminous sources are amongst the most powerful radio sources known in the Universe. For comparison, typical powerful radio galaxies at low redshift have few$\times 10^{25-26}$ W Hz$^{-1}$ [e.g., @wall85; @tadhunter93].

VLT/SINFONI observations and data reduction {#ssec:obsdatred}
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Observations were carried out with the near-infrared imaging spectrograph SINFONI on UT4 of the Very Large Telescope of ESO between September 2009 and September 2012 under program IDs 079.A-0617, 081.A-0468, 381.A-0541, 082.A-0825, and 083.A-0445. SINFONI is an image slicer which operates in the J, H, and K-band in a contiguous 8$\times$8 field of view at a pixel scale of 125 mas$\times$250 mas. The spatial resolution of most of our data is set by the size of the seeing disk, between 0.6 and 1.5. The size of the seeing disk for individual galaxies in shown as a black ellipse in the lower left corner of each line map in Figs. \[fig:maps\] to \[fig:maps5\]. At z$\sim$2, 1.2 corresponds to 10 kpc. This is comparable to a 