EMISSION FROM THE Z = 2 DAMPED LY-ALPHA ABSORBER TOWARD Q1215+333

We have detected narrow emission lines at 1.118-mu-m and 1.456-mu-m in the spectrum of the z = 2.606 quasar Q1215 + 333, corresponding to [O II] lambda-3727 and H-beta at z = 1.9984, the redshift of a damped Ly-alpha absorber toward this quasar. The intensity of the H-beta line is 7.6 +/- 2 x 10(-16) ergs cm-2 s-1, which corresponds to a line luminosity of 5 x 10(42) ergs s-1 h100(-2) (q0 = 0.5). If we assume that the photoionization producing the emission is due purely to massive star formation with a Salpeter initial mass function, we find a total star formation rate of 100 M. yr-1 h100(-2). Given the uncertainty in the initial mass function and cosmological parameters, this star formation rate is very uncertain. However, the star formation rate is well above those inferred from Ly-alpha emission-line searches of similar systems, implying effective destruction of Ly-alpha photons. The intensity of the [O II] lambda-3727 line is 1.6 +/- 0.3 x 10(-15) ergs cm-2 s-1. The ratio [O II]/H-beta-almost-equal-to 2 and the weakness of the ratio [O II] lambda-5007/H-beta < 0.5 is typical of star formation regions with gas at nearly solar metallicity.