2000A&A...356L...9L

We present optical (ultraviolet rest-frame) spectropolarimetric observations of the rare iron low ionization broad absorption line (BAL) QSO Q0059-2735. The continuum polarization increases to the blue with a regular rotation of the polarization position angle, suggesting that at least two mechanisms are at the origin of the polarization. There is also some evidence for dilution by a Fe II pseudo-continuum in emission. In the broad absorption lines, the polarization strongly rises, with the largest values ever reported. On the contrary, the Fe II blends in absorption are not more polarized than the continuum, while they are clearly visible in the polarized flux. These different polarization properties of Fe II absorption lines suggest a different origin and/or geometry. The observed properties of Q0059-2735 are consistent with a hybrid QSO/ starburst model.