2004AJ....128.1219J

We present Australia Telescope Compact Array mosaic H I imaging of the Local Group dwarf irregular galaxy WLM. We find an integrated flux of 149 Jy km/s and a total H I mass of (3.2±0.3)x10⁷M_☉. The major axis of the H I is aligned with the stellar component of the galaxy. The overall H I distribution is relatively smooth at our resolution and has a double-peaked central core. One of these peaks is aligned with a region found to have extinction that is internal to WLM, and we take this as possible evidence of a large molecular gas complex in the southern half of the galaxy. The other H I peak is in close proximity to the brightest H II regions. WLM's overall velocity field is consistent with rigid-body rotation. A rotation curve is derived, and we find a total dynamical mass of (3.00±0.80)x10⁸M_☉. We also performed a wide-field search, 38' in radius, for H I companions or evidence of recent interactions (e.g., tidal tails) and found no detections to an H I mass limit of M_HI>8.4x10⁵M_☉.