SIMBAD references

Dwarf irregular galaxies are unique laboratories for studying the interaction between stars and the interstellar medium in low-mass environments. We present the highest spatial resolution observations to date of the neutral hydrogen content of the Local Group dwarf irregular galaxy WLM. We find that WLM's neutral hydrogen distribution is typical for a galaxy of its type and size and derive an H I mass of (6.3±0.3)x10⁷ M_☉. In addition, we derive an H I extent for WLM of ∼30', which is much less than the 45' extent found by Huchtmeier and coworkers. We show that the broken ring of high column density neutral hydrogen surrounding the center of WLM is likely the result of star formation propagating out from the center of the galaxy. The young stars and Hα emission in this galaxy are mostly correlated with the high column density neutral hydrogen. The gap in the central ring is the result of star formation in that region using up, blowing out, or ionizing all of the neutral hydrogen. Like many late-type galaxies, WLM's velocity field is asymmetric with the approaching (northern) side appearing to be warped and a steeper velocity gradient for the approaching side than for the receding side in the inner region of the galaxy. We derive a dynamical mass for WLM of 2.16x10⁹ M_☉.