A high-velocity narrow absorption line outflow in the quasar J212329.46 − 005052.9

Abstract

We report on the discovery of a high-velocity narrow absorption line outflow in the redshift 2.3 quasar J212329.46 − 005052.9. Five distinct outflow systems are detected with velocity shifts from −9710 to −14 050 km s^-1 and C IV λλ1548, 1551 linewidths of FWHM ≈ 62–164 km s^-1 . This outflow is remarkable for having high speeds and a degree of ionization similar to broad absorption line (BAL) flows, but linewidths roughly 100 times narrower than BALs and no apparent X-ray absorption. This is also, to our knowledge, the highest-velocity narrow absorption line system confirmed to be in a quasar outflow by all three indicators of line variability, smooth superthermal line profiles and doublet ratios that require partial covering of the quasar continuum source. All five systems have stronger absorption in O VI λλ1032, 1038 than C IV with no lower ionization metal lines detected. Their line variabilities also appear coordinated, with each system showing larger changes in C IV than O VI and line strength variations accompanied by nearly commensurate changes in the absorber covering fractions. The metallicity is approximately twice solar.