CCD photo-polarimetry of the jet of 3C 273.

Spatially resolved CCD photo-polarimetry in three bandpasses centered at 420, 610, and 860 nm revealed three different emission regions along the jet of 3C 273: (1) The radio hot spot at 21arcsec.2 from the quasar which has a sharp continuum fall off above 7×10¹³Hz and is therefore clearly detected in the I, but hardly visible in the R band. (2) The optical knot at 19arcsec.5 from the core terminating the visible jet image. The knot is 13% polarized at position angle 140° in the R band, degree and angle beeing identical with 5 GHz data. This and a radio-to-optical powerlaw f_ν ≡ ν^-0.96 are strong indications for a synchrotron origin of the knot emission. (3) The inner 11arcsec to 17arcsec of the jet, where no polarization stronger than 8% is detectable. This is in contrast to VLA observations at 5 GHz and is attributed to an additional unpolarized component observed at short wavelengths.