KnowraH I regionLinked fromLinked fromThe 3 pages that link to H I region, each with the reason it gives.All 3Related 2Compared with 1H II regionCompared with: Neutral hydrogen surrounds or lies ahead of the ionized gas.Galactic diskRelated: The line maps neutral hydrogen across galactic disks, including regions beyond bright stellar light.Effelsberg 100-metre Radio TelescopeRelated: The telescope maps hydrogen in the Milky Way and nearby galaxies.