Mass content of UGC 6446 and UGC 7524 through HI rotation curves:
  deriving the stellar discs from stellar population synthesis models
  In this work we study the mass distribution of two irregular galaxies, UGC
6446 and UGC 7524, by means of HI rotation curves derived from high resolution
HI velocity fields obtained through the Westerbork Synthesis Radio Telescope
data archive. We constrain the stellar and gas content of both galaxies with
stellar population synthesis models and by deriving the HI+He+metals rotation
curves from the total HI surface density maps, respectively. The discrepancy
between the circular velocity maxima of the stellar plus the HI+He+metals
rotation curves and the observed HI rotation curves of both galaxies requires
the inclusion of a substantial amount of dark matter. We explore the Navarro
Frenk and White, Burkert, Di Cintio, Einasto and Stadel dark matter halo
models. We obtain acceptable fits to the observed HI rotation curves of UGC
6446 and UGC 7524 with the cored Burkert, Einasto and Stadel dark matter halos.
In particular, Einasto and Stadel models prove to be an appropriate alternative
to the Burkert dark matter halo. This result should increase the empirical
basis that justify the usage of dark matter exponential models to adjust the
observed rotation curves of real galaxies.
