SIMBAD references

We present subarcsecond optical imaging and polarization observations of five optical hot spot candidates in the classical double radio sources 3C 111, 3C 303, 3C 351, 3C 390.3, and PKS 2135-147. On the basis of positional coincidence, optical appearance, and polarization, all four 3C sources appear to have genuine optical counterparts to radio hot spots, whereas in PKS 2135-147 the hot spot candidate turns out to be an unrelated field galaxy. We also confirm the first ever optical double hot spot in the source 3C 351.