Density Law of Spiral Galaxy Relative to Rotation Curves

An expression for galactic density has been derived from galactic rotation curves using Burbidge technique, in which rotational velocity v(r) is related to the galactic density at a given distance r. Abel's integral has been used to evaluate the galactic density (r, k). The derived density law has been applied to spiral galaxies with a general observed rotation curves with a turn-over at some distance rt, so we got two different density forms 1(r, k) and 2(r, k) for the core and for disk and halo of the galaxy respectively.