Detection of CO emission in the elliptical galaxies NGC 3265 and NGC 5666

From observations of seven elliptical galaxies selected by the strength of their far-infrared (FIR) fluxes, the detection of CO (2 - 1) in the central regions of NGC 3265 and NGC 5666, classified as E4 and Ec, respectively, is reported. Observed with the FWHM beam of 17 arcsec of the IRAM telescope, the CO radial velocities and line widths agree well with H I spectra emitted from a much more extended region, caused partly by rigid rotation in their nuclear regions but also implying a contribution from extensive noncircular motions in the interstellar gas. The shapes of the CO profiles indicate velocity structure within the beam. The observational ratios of CO/H I fluxes are similar to those found in early-type galaxies. The data also imply H2 masses of 1.7 x 10 to the 8th and 3.8 x 10 to the 8th solar masses for the central regions of NGC 3265 and NGC 5666, respectively, giving for those regions H2/H I mass ratios of about three that are comparable to what is observed for the inner region of the Milky Way. 29 refs