IMAGING AND 2-DIMENSIONAL SPECTRA OF THE IR-BRIGHT GALAXY NGC-2146 - A RECENT LOW-ENERGY MERGER

We present new data on the IR-luminous galaxy NGC 2146 from several sources: direct imaging in B, R, and Hα; IR imaging in the J, H, and K bands; long-slit spectroscopy at optical and IR wavelengths; and scanning étalon observations in Hα. The results allow measurement of the interstellar extinction in the dust lane, and estimation of the true luminosity of the galaxy and nuclear regions. The spectra indicate that there is no active nucleus, and measure the changing ratio of forbidden to permitted lines across the galaxy. IR images and colors indicate the existence of a significant population of hot young stars in the central regions of the system. The Hα velocity maps show the full radial-velocity pattern, and suggest that the system consists of a disturbed disk and a merging or interacting arm which connects to the inner dust and radio structures. Outer Hα and H I structures appear to be the earlier remnants of this spiraling merger.