南方基地知识库

Very few low-ionization broad absorption line (LoBAL) QSOs have been found at high redshifts, to date. One high-redshift LoBAL QSO, J0122+1216, was recently discovered by the Lijiang 2.4 m Telescope, with an initial redshift determination of 4.76. Aiming to investigate its physical properties, we carried out follow-up observations in the optical and near-IR spectroscopy. Near-IR spectra from UKIRT and P200 confirm that it is a LoBAL, with a new redshift determination of 4.82 +/- 0.01 based on the Mg II emission-line. The new Mg II redshift determination reveals strong blueshifts and asymmetry of the high-ionization emission lines. We estimate a black hole mass of similar to 2.3 x 10(9) M-circle dot and Eddington ratio of similar to 1.0 according to the empirical Mg II-based single-epoch relation and bolometric correction factor. It is possible that strong outflows are the result of an extreme quasar environment driven by the high Eddington ratio. A lower limit on the outflowing kinetic power (>0.9% L-Edd) is derived from both emission and absorption lines, indicating that these outflows play a significant role in the feedback process that regulates the growth of its black hole, as well as host galaxy evolution.