The gas content of peculiar galaxies: counterrotators and polar rings

This paper studies the global ISM content in a sample of 104 accreting galaxies, including counterrotators and polar rings, which spans the entire Hubble sequence. The molecular, atomic and hot gas content of accretors is compared to a newly compiled sample of normal galaxies. We present results of a small survey of the J=1–0 line of CO with the 15m SEST telescope on a sample of 11 accretors (10 counterrotators and 1 polar ring). The SEST sample is enlarged with published data from 48 galaxies, for which observational evidence of counterrotation in the gas and/or the stars has been found. Furthermore, the available data on a sample of 46 polar ring galaxies has been compiled. In order to explore the existence of an evolutionary path linking the two families of accretors, the gas content of counterrotators and polar rings is