Ram-pressure stripping of the interstellar medium in NGC 4485

This paper describes submm, (CO)-C-12 (J = 2-1) observations of the interac ting pair of galaxies NGC 4490 and 4485, and together with high resolution H I and multifrequency radio continuum data we investigate the evolution of the ISM in this system. We find the following. (i) The smaller member of t he pair, NGC 4485, has had the atomic, molecular and dust components of its ISM stripped via ram pressure during its recent passage through the extend ed H I distribution of NGC 4490. A bow-shock is identified in the H I ahead of the stripped gas. (ii) Within the disc of NGC 4490 we find a very low H -2-to-H I ratio as well as a strong correlation between thermal emission an d mass of H-2 suggesting that the star formation rate is limited in this ca se by the conversion of H I to H-2. (iii) (CO)-C-12 emission from an H I an d radio-continuum bridge between the two galaxies is detected.