Title:[0555] All-sky survey: neutral hydrogen Caption:This slide shows the distribution of neutral hydrogen (HI) gas in the galaxy measured through 21-cm radio observations. The relative amounts (column densities) of neutral hydrogen are shown in false colors with black and dark blue regions having the smallest, and red and white regions the largest amounts. As this slide shows, the neutral hydrogen is strongly concentrated in the galactic plane. At high galactic latitudes the gas shows a filamentary structure. These filaments arise from low-velocity gas (nearby - less than 200 pc from the Sun) and follow the local magnetic field. These low-velocity filaments may arise through stellar winds from massive stars that create bubbles in the interstellar medium. Copyright:(c) Smithsonian Astrophysical Observatory Credit:Smithsonian Institution Astrophysical Observatory