| Abstract | We investigated the possible influence on the Tully-Fisher relation of active massive star formation in IRAS galaxies, in order to estimate the contribution of star formation to their near-infrared luminosity. We observed 60 galaxies from the infrared complete so-called IRAS Minisurvey sample in the 21 cm H I line at Arecibo, determined the near-infrared (H- band) Tully-Fisher relation for the 36 objects in the sample we judged to be usable for this purpose, and compared this relation with that of optically selected normal galaxies. The results show no significant enhancement of the near-infrared luminosities of the IRAS Minisurvey galaxies compared to those of the optically selected normal galaxies. From these results we inferred that in the Minisurvey galaxies the average contribution of the active massive star formation to the total near-infrared luminosity is less than about 50%. Starburst model calculations indicate, however, that this contribution probably exceeds 20%, and that exponential decay times for the starbursts occurring in the Minisurvey galaxies are of the order of 10 Myr. The Tully-Fisher relation shows one exceptional galaxy (IRAS 03565 + 2139) with an about 25 times higher luminosity than average for its rotational velocity. |
