Abstract

Intermediate resolution observations of the line and continuum polarization of the Seyfert galaxy NGC 4151 are presented. The emission lines are polarized by a different amount and at a different position angle than the continuum. The line polarization is produced by a screen covering the nucleus, either as dust on the outer edges of the emitting cloud structure or as interstellar polarization in NGC 4151. The intrinsic polarization of the nuclear source shows a strong wavelength dependence and is produced interior to the gas-emitting region which produces the broad wings of the permitted lines. The continuum observations are consistent with electron scattering or a nonthermal mechanism if the polarization is diluted in the red by starlight; however, dust scattering in an asymmetrical cloud surrounding the nucleus cannot be ruled out.