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It has been shown based on radio variability arguments that some BALQSOs (broad absorption line quasars) are viewed along the polar axis (orthogonal to accretion disk) in the recent article of Zhou et al. These arguments are based on the brightness temperature, $T_{b}$ exceeding $10^{12} ^{\circ}$ K which leads to the well-known inverse Compton catastrophe unless the radio jet is relativistic and is viewed along its axis. In this letter, we expand the Zhou et al sample of polar BALQSOs to the entire SDSS DR5. In the process, we clarify a mistake in their calculation of brightness temperature. The expanded sample of high $T_{b}$ BALQSOS, has an inordinately large fraction of LoBALQSOs (low ionization BALQSOs). We consider this an important clue to understanding the nature of the polar BALQSOs. This is expected in the polar BALQSO analytical/numerical models of Punsly in which LoBALQSOs occur when the line of sight is very close to the polar axis, where the outflow density is the highest.Comment: To appear in ApJ Letter

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We report on the first high frequency VLBI observations of the nearby broad absorption line quasar (BALQSO), Mrk 231. Three epochs of observations were achieved at 15 GHz and 22 GHz, two of these included 43 GHz observations as well. The nuclear radio source is resolved as a compact double. The core component experienced a strong flare in which the flux density at 22 GHz increased by > 150% (45 mJy) in three months. Theoretical models of the flare imply that the emission is likely enhanced by very strong Doppler boosting of a highly relativistic ejecta with a kinetic energy flux, Q ∼ 3 × 10 43 ergs/sec. Combining our data with two previous epochs of 15 GHz data, shows marginal evidence for the slow advance of the secondary component (located ≈ 0.97 pc from the core) over a 9.4 year span. We estimate that the long term time averaged kinetic energy flux of the secondary at Q ≈ 10 42 ergs/sec. Low frequency VLBA observations indicate that the secondary is seen through a shroud of free-free absorbing gas with an emission measure of ≈ 10 8 cm −6 pc. The steep spectrum secondary component appears to be a compact radio lobe that is associated with a working surface between the ram-pressure confined jet, and a dense medium that is likely to be the source of the free-free absorption. The properties of the dense gas are consistent with the temperatures, displacement from the nucleus and the column density of total hydrogen commonly associated with the BAL wind.