The Twice-Overlooked, Second Fanaroff-Riley II Broad Absorption Line Quasar LBQS 1138−0126

Abstract

We report the correct classification of an overlooked Fanaroff-Riley class II radio-loud quasar with broad absorption lines, only the second such object so identified. The rare properties of this quasar, LBQS 1138-0126, are twice overlooked. First, LBQS 1138-0126 was found in the Large Bright Quasar Survey but only noted as a possible broad absorption line quasar without additional follow-up. Later, LBQS 1138-0126 was rediscovered and classified as a radio-loud broad absorption line quasar but not recognized as an FR II radio source. We describe the radio, absorption line, and optical polarization properties of LBQS 1138-0126 and place it in context with respect to related quasars. In particular, spectropolarimetry shows that LBQS 1138-0126 has high continuum polarization increasing from 3% in the red (rest-frame 2400 A) to over 4% in the blue (rest-frame 1650 A), essentially confirming the intrinsic nature of the absorption. The polarization position angle rotates from ~-30° in the red to ~0° in the blue; the radio lobe position angle is ~52° for comparison. LBQS 1138-0126 is additionally notable for being one of the most radio-loud broad absorption line quasars and for having low-ionization broad absorption lines as well.