1999ApJ...514..675P

We present velocity-resolved spectroscopy in the Brγ near-infrared hydrogen recombination line of the center of the starburst galaxy NGC 1614. The line profile exhibits two peaks that are interpreted as arising from the two condensations observed in recent mid-infrared and radio continuum images. From analysis of the line profile and source extent, we conclude that the clumps are unlikely to be in virial equilibrium; however, we estimate a mass for each of 1.6x10⁹ M_☉ by assuming that they are in barycentric motion. We compare newly derived radiative properties of the nuclear region, including the extinction-corrected ionization rate, bolometric luminosity, and stellar CO and Brγ equivalent widths, as well as the dynamical mass, with recent models of the star formation history and stellar initial mass function. The most plausible scenarios are of (1) continuous star formation (or minibursts at several sites with a range of ages) and a Salpeter initial mass function truncated at 30 M_☉, or (b) an instantaneous burst (6-8)x10⁶ yr ago.