Infrared imaging of WENSS radio sources

We have performed deep imaging in the IR J- and K- bands for three sub-samp les of radio sources extracted from the Westerbork Northern Sky Survey, a l arge low-frequency radio survey containing Ultra Steep Spectrum (USS), Giga hertz Peaked Spectrum (GPS) and Flat Spectrum (FS) sources. We present the results of these IR observations, carried out with the ARcetri Near Infrare d CAmera (ARNICA) at the Nordic Optical Telescope (NOT), providing photomet ric and morphologic information on high redshift radio galaxies and quasars . We find that the radio galaxies contained in our sample do not show the p ronounced radio/IR alignment claimed for 3CR sources. IR photometric measur ements of the gravitational lens system 1600+434 are also presented.