Flying around a warped HI disk.
In the following movie we show how a galaxy with a warped and twisted disk structure appears to the observer as he views the galaxy from different directions. The warped and twisted structure of the disk is calculated by Kimberly Barker New, who derived an analytic solution to the 'twisted-disk' equations. These describe the dynamics of a viscous accretion disk in the potential of an oblate spheroidal, logarithmic and scale-free halo. In each frame of the movie, three images are shown. On the left is a three-dimensional rendering of the disk that shows its warped and twisted structure. This image was produced by Howard Cohl using IDL. In the middle, the surface brightness is shown in the 21 cm line of neutral hydrogen. On the right, the projected velocity map is displayed. It is these latter two images that can be compared to radio observations of galaxies in the 21 cm line. These two images were produced by Horst Väth with his 3D radiative transfer code running on the massively parallel single instruction multiple data (SIMD) computer MasPar MP-1 of LSU.
Flying around a warped HI disk.