Paper detail

Cores in Classical Dwarf Spheroidal Galaxies? A Dispersion-Kurtosis Jeans Analysis Without Restricted Anisotropy

We attempt to measure the density of dark matter in the two Dwarf Spheroidal Galaxies Fornax and Sculptor using a new method which employs Jeans equations based on both the second and fourth moment of the Collisionless Boltzmann Equation (i.e. variance and kurtosis of line of sight stellar velocities). Unlike previous related efforts, we allow the anisotropy of the radial and tangential second and fourth order moments to vary independently of each other. We apply the method to simulated data and establish that to some degree it appears to be able to break the degeneracies associated with second order only Jeans analyses. When we apply the technique to real data, we see no huge improvement in our understanding of the inner density of Fornax, which can still be fit by either a quite cuspy or cored density profile. For Sculptor however we find that the technique suggests that the data is incompatible with a steep profile and a cored profile seems more consistent. As well as presenting these new results and comparing them to other estimates in the literature, we try to understand why the technique is more effective in one system than the other.