Chandra X-Ray Observations of Radio-Loud Broad Absorption Line Quasars

Abstract

We report the results of a Chandra X-Ray Observatory survey of five formally radio-loud broad absorption line (BAL) quasars. These five objects include BAL quasars with a range of properties, including both high- and low-ionization BALs. All five BAL quasars are detected in 5 ks ACIS-S exposures, with counts ranging from 12 to 55. The X-ray count rates are down by factors of 40 or more compared to expectations based on the spectral energy distributions of normal, unabsorbed radio-loud quasars; this is the same sort of behavior seen in radio-quiet BAL quasars. Interestingly, the hardness ratios are rather soft and inconsistent with absorption from a neutral hydrogen column density large enough to suppress the X-rays as observed. We conclude that in many cases the X-rays emanating from BAL quasars must be reflected, scattered, or leaked through an ionized absorber or a neutral absorber that does not completely cover the X-ray source (covering ≥98%), or that we are seeing an unabsorbed X-ray source perhaps associated with a radio jet. Much higher counts are required to distinguish among these possibilities. We note several suggestive correlations involving X-ray properties that require verification using larger samples. One source, FIRST J1556+3517, appears to be the X-ray brightest low-ionization BAL quasar known, other than the special case of the nearby Mrk 231. The very faint X-ray emission from FIRST J1044+3656 is consistent with significant obscuration, which strongly favors the multiphase X-ray shielding models of this object in the literature.