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Session 84 - QSOs and BL Lacs.
Display session, Wednesday, January 17
North Banquet Hall, Convention Center
We present optical broad-band polarimetry and spectropolarimetry of the low redshift Broad Absorption Line (BAL) QSO PG 1700+518. The average observed optical polarization is low (\sim 1%), but features associated with the emission lines are clearly present in the percentage polarization and position angle spectra. While not obviously present in total flux, broad absorption from H\beta, and probably from H\alpha, is detected in the polarized flux spectrum. The H\beta absorption starts at the emission line peak and extends to shorter wavelengths by \sim 5600 km s^-1. This is in contrast to the detached and quite broad (\ge 10,000 km s^-1) MgII \lambda 2798 and CIV \lambda 1549 absorption lines seen in the UV total flux spectrum (Turnshek et al. 1985, ApJ, 294, L1; Pettini amp; Boksenberg 1985, ApJ, 294, L73)
We Discuss the possible polarization mechanisms, and the implications of these results for the structure of BALQSOs.
Program listing for Wednesday