We present new near-infrared (rest-frame UV-to-optical) spectra of the high-redshift, gravitationally lensed quasar B1422 + 231 (z = 3.62). Diagnostic emission lines of Fe II, O III λ5007, and Hβ, 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)/Hβ = 18.1 ± 4.6 and Fe II (optical)/ Hβ = 2.3 ± 0.6 are higher than those reported by Kawara et al. by factors of 1.6 and 3.3, respectively, although the ratio [O III] λ5007/Hβ = 0.19 ± 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)/Hβ ratios, the line ratio measured for B1422+ 231 are consistent with the observed range of Fe II (optical) ratios of low-z quasars.
- Quasars: emission lines
- Quasars: individual (B1422 + 231)
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science