We present new near-infrared ( rest-frame UV-to-optical ) spectra of the high redshift , gravitationally lensed quasar B 1422+231 ( z = 3.62 ) .
Diagnostic emission lines of Fe ii , O iii \lambda 5007 , and H \beta , commonly used to determine the excitation , ionization , and chemical abundances of radio-quiet and radio-loud quasars , were detected .
Our new data show that the ratio Fe ii ( UV ) /H \beta = 18.1 \pm 4.6 and Fe ii ( optical ) /H \beta = 2.3 \pm 0.6 are higher than those reported by Kawara et al .
( 1996 ) by factors of 1.6 and 3.3 , respectively , although the ratio [ O iii ] 5007/H \beta = 0.19 \pm 0.02 is nearly the same between the two measurements .
The discrepancy of the line flux ratios between the measurements is likely due to improved data and fitting procedures rather that to intrinsic variability .
While approximately half of the high- z quasars observed to date have much more extreme Fe ii ( optical ) /H \beta ratios , the line ratio measured for B 1422+231 are consistent with the observed range of Fe ii ( optical ) ratios of low- z quasars .