2012AJ....143...98W

We report the results of long-slit spectroscopy at position angles 68°, 131°, and 164° for the minor-merger NGC 4194, a luminous infrared starburst galaxy. The mass within 1.2 kpc of the dynamical center is estimated to be 4.8x10⁹ to 1.7x10¹⁰ M_☉, depending on the assumed inclination to the plane of the sky. The star formation rate (SFR) in the areas sampled is 8 M_☉/yr. The metallicity, log(O/H) + 12, ranges from ∼8.8 to >9.0 in regions of significant star formation, suggesting that the metallicity has been enhanced by the current star formation. The star-forming regions range in age from 5 to 9 Myr, with the youngest ages occurring in the regions of high SFR. Electron temperatures and the location of the spectra in emission line diagnostic diagrams suggest the presence of shock waves, presumably due to the presence of supernovae, winds from massive stars, and/or collisions of clouds due to the merger. The presence of massive stars and supernovae is consistent with the ages determined for the star-forming regions. The ages of the continua produced by the stellar population are estimated to range from 10 Myr to 5 Gyr. Much of the stellar population represented in the continua was probably formed before the merger and represents the progenitor galaxies.