Spectroscopy of Luminous Infrared Galaxies at 2 Microns. II. Data for Galaxies with 11.2 ≤ log ( L IR / L ☉ ) ≤ 11.9

Publisher Website
Google Scholar
Abstract
Spectra across the infrared K band are presented for a flux-limited sample of powerful, bright, "infrared" galaxies. The sample in the present paper, consisting of 43 systems (47 individual galaxies) with infrared luminosities LIR in the range 11.2 log (LIR/L☉) 11.9, was chosen from the IRAS Bright Galaxy Catalogue. The spectra have resolving powers of ~340-680. When combined with the 13 spectra we have already published for the "ultraluminous" galaxies, those with log (LIR/L☉) 12.0, this constitutes the largest database of high-quality infrared spectra yet assembled for a well-defined sample of galaxies. The spectra are, in general, dominated by emission lines, which are due to the Brγ hydrogen recombination line and to several quadrupole transitions of excited molecular hydrogen. Emission from He I also appears frequently. Deep absorption bands from CO are present in virtually all the spectra, as are a variety of weaker stellar absorption features. The data are analyzed in a companion paper (Paper III).