Hosts and Alignment Effect in 0.5 < z < 1 radio sources

Abstract

R- and I- band images with good seeing at the NOT of the hosts of a sample of 7C radio galaxies at z ~ 0.7 (with mean radio flux 20 times fainter than the 3C sample) show some evidence of radio-optical alignment. A quantitative analysis of the alignment in this sample and in a corresponding 3C sample from HST archival data indicates that the percentage of aligned flux may be lower and of smaller spatial scale in the faint radio sample. Studies of the aligned material in z ~ 1 3C source hosts indicate that the quasar extensions also show some aligned flux, though much of it is due to optical synchrotron radiation.