Unexpected stellar velocity distribution in the warped Galactic disk
Publication date: 02 Apr 1998
Authors: Smart, R. L., et al.
Copyright: Nature PublishingIt is now over 40 years since the gaseous disc of our galaxy was discovered to be warped from radio observations of neutral hydrogen . Subsequently the warp has been detected in the distribution of galactic dust , molecular clouds , and luminous stars [4,5]. Roughly half of all spiral galaxies have similarly warped discs, which suggests that warps are common and long-lived phenomenon. However, there is still no consensus as to what induces galactic discs to become warped: intergalactic winds, tidal interactions with satellites, magnetic pressure and massive dark halos have all been proposed as causative agents. Here we use data from the Hipparcos satllite  to probe the Milky Way's warp.