New Detections of Optical Emission from Kiloparsec-scale Quasar Jets
  We report initial results from the detection of optical emission in the arcsecond-scale radio jets of two quasars utilizing images from the {\it Hubble Space Telescope} archive. The optical emission has a very knotty appearance and is consistent with synchrotron emission from highly relativistic electrons in the jet. Combining these observations with those of previously reported features in other quasars, an emerging trend appears to be that their radio-to-optical spectral indices are steeper than those of similar features in jets of lower power radio sources. 
C. C. Cheung, J. F. C. Wardle, Tingdong Chen, S. P. Hariton