VLBI Detections of Parsec-Scale Nonthermal Jets in Radio-Loud Broad
  Absorption Line Quasars
  We conducted radio detection observations at 8.4 GHz for 22 radio-loud broad
absorption line (BAL) quasars, selected from the Sloan Digital Sky Survey
(SDSS) Third Data Release, by a very-long-baseline interferometry (VLBI)
technique. The VLBI instrument we used was developed by the Optically ConnecTed
Array for VLBI Exploration project (OCTAVE), which is operated as a subarray of
the Japanese VLBI Network (JVN). We aimed at selecting BAL quasars with
nonthermal jets suitable for measuring their orientation angles and ages by
subsequent detailed VLBI imaging studies to evaluate two controversial issues
of whether BAL quasars are viewed nearly edge-on, and of whether BAL quasars
are in a short-lived evolutionary phase of quasar population. We detected 20
out of 22 sources using the OCTAVE baselines, implying brightness temperatures
greater than 10^5 K, which presumably come from nonthermal jets. Hence, BAL
outflows and nonthermal jets can be generated simultaneously in these central
engines. We also found four inverted-spectrum sources, which are interpreted as
Doppler-beamed, pole-on-viewed relativistic jet sources or young radio sources:
single edge-on geometry cannot describe all BAL quasars. We discuss the
implications of the OCTAVE observations for investigations for the orientation
and evolutionary stage of BAL quasars.
