HST polarization observations of NGC 1068

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Session 59 -- Low Luminosity AGNs and Active Galaxies
Display presentation, Thursday, 2, 1994, 9:20-6:30

[59.06] HST polarization observations of NGC 1068

A. Capetti, F.D. Macchetto, W.B. Sparks, D.J. Axon (STScI)

We present the results of HST polarization observations of NGC 1068 taken with the Faint Object Camera in the ultraviolet and the Wide Field Planetary Camera in the visual.

The accuracy achieved in the polarization measurements is very high with typical errors not exceeding 2 degrees for the position angle. The agreement with previous ground based observations is excellent.

The FOC polarization vectors are disposed in a circular pattern, as expected in case of scattering of a point source. We can accurately determine the position of the nuclear source.

The polarization of the featureless continuum is generally $\sim$ 10 \% but is as high as 60 \% on the North East knot. Two clouds of very high polarization are seen within 0".1 from the derived position of the nucleus; they are possibly directly associated with the active nucleus.

The analysis of the WFPC images is more complex; the strong [O III] lines are superimposed to the continuum emission. The polarization structure is in fact dominated by two different structures associated with the two emission components.

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