Spectropolarimetry of FIRST 0840+3633

Abstract

We present Keck spectropolarimetry of a rare ``Iron Lo-BALQSO,'' FIRST 0840+3633. The continuum is 4% polarized near 2000 angstroms rest-frame, but falls to 2% at longer wavelengths, and maintains a relatively constant position angle of 50 degrees. The emission lines are unpolarized. The polarization increases up to 8% in the low-ionization absorption troughs of Mg II 2800 and Al III 1860. The polarization and its position angle vary in a complicated manner across the metastable Fe II absorption lines, suggesting that more than one mechanism is at work or that the system geometry is complex.

4 pages, 1 figure. LaTeX with encapsulated postscript. To appear in the proceedings of the workshop on "Mass Ejection from AGN", Pasadena, 1997 Feb