The Issue of Scale Length

A few authors (Pohlen, Dettmar & Lutticke 2000, Kregel, van der Kruit, Grijs 2002) have proposed that there is a correlation between disk truncation radii and disk scale length (figure 1).

(Pohlan et. al. 2000).

To investigate this, we ran a model exactly like the NGC 7252 model only with each of the disks having a scale length of double the origional one. We we saw a considerable shift in the mass profiles.
Double Scale Length Plot

This means that any constraint we put on truncation radii must be a function of scalelength, and complicates our project.