A wide-field H I study of the NGC 1566 group

Abstract

We report on neutral hydrogen observations of a ∼5.5 × 5.5 deg2 field around the NGC 1566 galaxy group with the multibeam narrow-band system on the 64-m Parkes Telescope. We detected 13 H I sources in the field, including two galaxies not previously known to be members of the group, bringing the total number of confirmed galaxies in this group to 26. Each of the H I galaxies can be associated with an optically catalogued galaxy. No 'intergalactic H I clouds' were found to an Hi mass limit of ∼3.5 × 108M⊙. We have estimated the expected H I content of the late-type galaxies in this group and find that the total detected H I is consistent with our expectations. However, while no global H I deficiency is inferred for this group, two galaxies exhibit individual H I deficiencies. Further observations are needed to determine the gas removal mechanisms in these galaxies.