galaxy [@Rusli13b]. A summary of the relevant galaxy properties is given in Table \[tab:data\].

Schwarzschild Modeling
----------------------

The population of stellar orbits is determined by fitting Schwarzschild orbit-superposition models to these data. In our models we assume the mass density $\rho$ of the galaxies to be described by $$\label{eq:density}
\rho(r) = {M_\bullet}\times \delta(r) + \Upsilon \times \nu(r) + \rho_\mathrm{DM}(r),$$ where ${M_\bullet}$ is the mass of the central SMBH, $\Upsilon$ is the stellar mass-to-light (M/L) ratio and $\nu$ denotes the deprojected galaxy luminosity density. The DM density $\rho_\mathrm{DM}$ is modeled by a logarithmic halo, which is constrained by two parameters that are included in the fit[^1]. Taking into account the effect of a DM halo is essential to derive unbiased black hole masses [@Gebhardt09; @Rusli13a] and, as we will show in Section \[subsec:dm\], to derive an unbiased orbit distribution.

To determine the best-fitting mass models, we proceed in two steps. We first omit the central high-resolution SINFONI data and only vary $\Upsilon$ and the DM density $\rho_\mathrm{DM}$. From this first set of models, we determine $\rho_\mathrm{DM}(\Upsilon)$, the best-fitting DM density distribution as a function of $\Upsilon$. For the final set of models, we include the central kinematical constraints from our SINFONI 