CO VERSUS H-I IN THE TULLY-FISHER RELATION FOR A SAMPLE OF 32 GALAXIES

As a basic step for establishing the CO-line Tully-Fisher relation for distant galaxies, we made a comparative study of HI versus CO line pr ofiles. Total line profiles of the CO line emission from 32 galaxies h ave been compared with the corresponding HI emission. We found a good correlation between the profiles of CO and HI. This strongly supports the thesis that CO can be used in the Tully-Fisher relation for distan t galaxies where HI observations cannot reach. We also argue that CO c an be used as an alternative to HI for non-isolated galaxies such as t hose in dense cluster of galaxies. Using the B-magnitudes and a recent calibration of the HI Tully-Fisher relation we give the distances for the galaxies derived from the CO-line Tully-Fisher relation and compa re them with the corresponding HI distances.