Age dating of a high-redshift QSO B1422+231 at z=3.62 and its cosmologicalimplications

The observed Fe II (UV + optical)/Mg II lambda lambda 2796, 2804 flux ratio from a gravitationally lensed quasar B1422 + 231 at z = 3.62 is interprete d in terms of detailed modeling of photoionization and chemical enrichment in the broad-line region (BLR) of the host galaxy. The delayed iron enrichm ent by Type Ia supernovae is used as a cosmic clock. Our standard model, wh ich matches the Fe II/Mg II ratio, requires the age of 1.5 Gyr for B1422 231 with a lower bound of 1.3 Gyr, which exceeds the expansion age of the E instein-de Sitter Ohm(0) = 1 universe at a redshift of 3.62 for any value o f the Hubble constant in the currently accepted range, H-0 = 60-80 km s(-1) Mpc(-1). This problem of an age discrepancy at z = 3.62 can be unraveled i n a low-density Ohm(0) less than or similar to 0.2 universe, either with or without a cosmological constant, depending on the allowable redshift range of galaxy formation. However, whether the cosmological constant is a requi red option in modern cosmology awaits a thorough understanding of line tran sfer processes in the BLRs.