Submillimeter observations of a sample of broad absorption line quasars

The broad absorption line (BAL) features seen in a small fraction of quasar optical/UV spectra are attributed to bulk outflows away from the quasar core. Observations suggest that dust plays a key role in these systems, although whether the inferred dust properties are a signature of orientation effects or whether they are indicative of an evolutionary sequence remains an outstanding issue. Submillimeter detections of BAL quasars (BALQSOs), which would clearly help to resolve this issue, have so far been sparse. This Letter reports on new submillimeter observations of seven BALQSOs. The strongest influence on the observed flux is found to be the redshift, with the two highest redshift sources appearing intrinsically more submillimeter-luminous than the lower redshift ones. Since this trend is also seen in other high-redshift active galactic nuclei (AGNs), including non-BAL quasars, it implies that the dust emission properties of these systems are no different from those of the general AGN population, which is difficult to reconcile with the evolutionary interpretation of the BAL phenomenon.