We present stellar-dynamical measurements of the central supermassive black hole ( SMBH ) in the S0 galaxy NGC 307 , using adaptive-optics IFU data from VLT-SINFONI .
We investigate the effects of including dark-matter haloes as well as multiple stellar components with different mass-to-light ( M / L ) ratios in the dynamical modeling .
Models with no halo and a single stellar component yield a relatively poor fit with a low value for the SMBH mass ( 7.0 \pm 1.0 \times 10 ^ { 7 } M _ { \sun } ) and a high stellar M / L ratio ( \Upsilon _ { K } = 1.3 \pm 0.1 ) .
Adding a halo produces a much better fit , with a significantly larger SMBH mass ( 2.0 \pm 0.5 \times 10 ^ { 8 } M _ { \sun } ) and a lower M / L ratio ( \Upsilon _ { K } = 1.1 \pm 0.1 ) .
A model with no halo but with separate bulge and disc components produces a similarly good fit , with a slightly larger SMBH mass ( 3.0 \pm 0.5 \times 10 ^ { 8 } M _ { \sun } ) and an identical M / L ratio for the bulge component , though the disc M / L ratio is biased high ( \Upsilon _ { K, { disc } } = 1.9 \pm 0.1 ) .
Adding a halo to the two-stellar-component model results in a much more plausible disc M / L ratio of 1.0 \pm 0.1 , but has only a modest effect on the SMBH mass ( 2.2 \pm 0.6 \times 10 ^ { 8 } M _ { \sun } ) and leaves the bulge M / L ratio unchanged .
This suggests that measuring SMBH masses in disc galaxies using just a single stellar component and no halo has the same drawbacks as it does for elliptical galaxies , but also that reasonably accurate SMBH masses and bulge M / L ratios can be recovered ( without the added computational expense of modeling haloes ) by using separate bulge and disc components .