INFRARED LINE EMISSION FROM HIGH-REDSHIFT GALAXIES .1. CALCULATIONS

The first generation of stars at high redshift should have produced br ight optical lines of common elements. These lines would appear now in near-infrared bands. We estimate the line fluxes and large-area surfa ce brightnesses of the prominent lines Ly alpha, H alpha, H beta, [O I II] lambda 5007, and [O II] lambda 3727 from the first galaxies under a variety of assumptions about the epochs of star formation and cosmol ogy. The results show that these galaxies are within the reach of the present generation of infrared instrumentation for a wide range of sta r formation histories. We discuss the efficacy of searching for emissi on-line objects in the near-infrared as a means of finding primeval ga laxies and discuss the possible searching strategies with respect to t he expected intrinsic scatter of the properties of the forming galaxie s.