Radio-loud quasars and broad absorption line (BAL) quasars (QSOs) each
constitute 10% of the total quasar population (Foltz et
al. 1990; Weymann et al. 1991) but have always appeared to be mutually
exclusive classes (Stocke et al. 1992). There is little agreement
about what determines quasar radio luminosities or what the
relationship is between broad absorption lines and radio power. The
BAL QSOs can be further subdivided into high and low-ionization
objects (Hi-BALs and Lo-BALs). The Lo-BALs make up only 10% of the
total BAL QSO population (Weymann et al. 1991) and are usually
recognized by the presence of broad absorption from Si II, Mg II, and
Al III. In the Lo-BAL population, there has for a decade been only one
object, 0059-2735, which also shows narrow absorption lines from
metastable excited states of Fe II and Fe III (Hazard et al. 1987). We
report here the discovery of two more ``iron Lo-BALs''.
We have undertaken two programs to identify candidate quasars drawn
from the NRAO Very Large Array (VLA)
FIRST
Survey (Becker, White, & Helfand 1995; White
et al. 1997). Both programs select optical samples for spectroscopy
by matching FIRST radio sources to stellar counterparts within
1
2 from the APM POSS I catalog (McMahon & Irwin 1992). The
FIRST Bright Quasar Survey (FBQS, Gregg et al. 1996) is developing a
new, complete sample of radio-selected quasars brighter than 17.5
magnitude on the E plates and with O - E < 2.0
. The
second program is searching specifically for high redshift quasars
among very red optical counterparts with O-E > 1.0 with the
additional constraint that the sources also have flat radio spectra
between 6 and 20 cm (Hook et al. 1996). The FIRST Survey quasar
search programs are unique in that they go to much fainter radio
levels than previous radio-selected QSO surveys: the 1 mJy flux limit
picks up radio-quiet objects out to z
2. Roughly half of
the objects in the FBQS pilot sample are, in fact, radio-quiet (Gregg
et al. 1996).
For the past two years we have been taking 5Å resolution spectra of
these quasar candidates using the Lick 3m Shane telescope, the Kitt
Peak National Observatory 2.1m and 4m telescopes, and the La Palma 2.5m
Isaac Newton telescope. To date, 136 new quasars with R
17.5 have been found in the FBQS and
30 additional quasars
have been found in the high redshift program.
Among the new QSOs in the FIRST Survey samples, there are 4 BAL QSOs. Two are of the common Hi-BAL variety, but the other two, one from each program, have very unusual spectra, placing them in the iron Lo-BAL class with the heretofor unique object 0059-2735 (Hazard et al. 1987). Additionally, one of these two is the first known radio-loud BAL QSO.