SIMBAD references

We present deep R band CCD images of a sample of 88 radio sources. The sources have an ultra-steep radio spectra and are taken from the Texas, Parkes and Molonglo catalogues. Of the 80 sources that do not have a diffuse radio morphology, 53 sources are identified to a limiting magnitude of R∼24. The reliability and completeness of the identifications are discussed using a likelihood method which takes into account the sizes of the radio sources. Basic source parameters, such as optical magnitudes, position angles and ellipticities are derived from the images. The distribution of the R-magnitudes peaks at 22.5<R<23, and is consistent with all the radio sources being associated with objects brighter than R=24.