We present axisymmetric , orbit-based models to study the central black hole , stellar mass-to-light ratio , and dark matter halo of NGC 4594 ( M104 , the Sombrero Galaxy ) .
For stellar kinematics , we use published high-resolution kinematics of the central region taken with the Hubble Space Telescope , newly obtained Gemini long-slit spectra of the major axis , and integral field kinematics from the SAURON instrument .
At large radii , we use globular cluster kinematics to trace the mass profile and apply extra leverage to recovering the dark matter halo parameters .
We find a black hole of mass M _ { \bullet } = ( 6.6 \pm 0.4 ) \times 10 ^ { 8 } M _ { \odot } , and determine the stellar M / L _ { I } = 3.4 \pm 0.05 ( uncertainties are the 68 % confidence band marginalized over the other parameters ) .
Our best fit dark matter halo is a cored logarithmic model with asymptotic circular speed V _ { c } = 376 \pm 12 \text { km s } ^ { -1 } and core radius r _ { c } = 4.7 \pm 0.6 kpc .
The fraction of dark to total mass contained within the half-light radius is 0.52 .
Taking the bulge and disk components into account in our calculation of \sigma _ { e } puts NGC 4594 squarely on the M - \sigma relation .
We also determine that NGC 4594 lies directly on the M - L relation .