Simulating Observations of Dark Matter Dominated Galaxies: Towards the   Optimal Halo Profile
  Low Surface Brightness (LSB) galaxies are dominated by dark matter, and their rotation curves thus reflect their dark matter distribution. Recent high-resolution rotation curves suggest that their dark matter mass-density distributions are dominated by a constant-density core. This seems inconsistent with the predictions of Cold Dark Matter (CDM) models which produce halos with compact density cusps and steep mass-density profiles. However, the observationally determined mass profiles may be affected by non-circular motions, asymmetries and offsets between optical and dynamical centres, all of which tend to lower the observed slopes. Here we determine the impact of each of these effects on a variety of halo models, and compare the results with observed mass-density profiles. Our simulations suggest that no single systematic effect can reconcile the data with the cuspy CDM halos. The data are best described by a model with a soft core with an inner power-law mass-density slope alpha = -0.2 +/- 0.2. However, no single universal halo profile provides a completely adequate description of the data. 
W.J.G. de Blok (1), A. Bosma (2), S.S. McGaugh (3) ((1) Cardiff   University, UK, (2) Observatoire de Marseille, France, (3)...