  In a previous paper (Olling 1995, astro-ph/9505002) a method was developed to
determine the shapes of dark matter halos of spiral galaxies from an accurate
determination of the rotation curve, the flaring of the gas layer and the
velocity dispersion in the HI. Here I report the results for the almost edge-on
Scd galaxy NGC 4244 (Olling 1996a,astro-ph/9605110; 1996b, astro-ph/9605111).
  The observed flaring of the HI beyond the optical disk puts significant
constraints on the shape of the dark matter halo, which are almost independent
of the stellar mass-to-light ratio. NGC 4244's dark matter halo is found to be
highly flattened with a shortest-to-longest axis ratio of 0.2 (-0.1,+0.3). If
the dark matter is disk-like, the data presented in this paper imply that the
vertical velocity dispersion of the dark matter must be 10% - 30% larger than
the measured tangential dispersion in the HI.

Astrophysics