The Detection of a Massive Chain of Dark H i Clouds in the GAMA G23 Field

Abstract We report on the detection of a large, extended H i cloud complex in Galaxy and Mass Survey G23 field, located at redshift z ∼ 0.03, observed as part MeerKAT Habitat Galaxies campaign (a pilot survey to explore mosaicing capabilities telescope). The complex, with total mass 10 10.0 M ⊙ , lies proximity large galaxy group dyn 13.5 . identify seven ɪ peak concentrations, interconnected tenuous chain structure, extending ∼400 kpc from east west, largest (central) concentration containing 9.7 gas distributed across 50 kpc. main source is not detected ultraviolet, optical, or infrared imaging. implied mass-to-light ratio ( I / L r ) extreme (>1000) even comparison other dark clouds has very little kinematic structure (110 km s −1 ), making it difficult rotation. Assuming pressure support, central > 10.2 while lower limit dynamical case full rotational support 10.4 If stable contain some amount unseen matter, but potentially less than for typical galaxy. It is, however, clear whether any gravitationally concentrations. faint UV-optical-infrared one smaller concentrations leading possible stellar association. system nature origins enigmatic, being result an interaction within appears be associated with.