Different massive black hole mass - host galaxy scaling relations suggest that the growth of massive black holes is entangled with the evolution of their host galaxies .
The number of measured black hole masses is still limited , and additional measurements are necessary to understand the underlying physics of this apparent co-evolution .
We add six new black hole mass ( M _ { BH } ) measurements of nearby fast rotating early-type galaxies to the known black hole mass sample , namely NGC 584 , NGC 2784 , NGC 3640 , NGC 4570 , NGC 4281 and NGC 7049 .
Our target galaxies have effective velocity dispersions ( \sigma _ { e } ) between 170 and 245 km s ^ { -1 } , and thus this work provides additional insight into the black hole properties of intermediate-mass early-type galaxies .
We combine high-resolution adaptive-optics SINFONI data with large-scale MUSE , VIMOS and SAURON data from ATLAS ^ { \textrm { 3 D } } to derive two-dimensional stellar kinematics maps .
We then build both Jeans Anisotropic Models and axisymmetric Schwarzschild models to measure the central black hole masses .
Our Schwarzschild models provide black hole masses of ( 1.3 \pm 0.5 ) \times 10 ^ { 8 } M _ { \sun } for NGC 584 , ( 1.0 \pm 0.6 ) \times 10 ^ { 8 } M _ { \sun } for NGC 2784 , ( 7.7 \pm 5 ) \times 10 ^ { 7 } M _ { \sun } for NGC 3640 , ( 5.4 \pm 0.8 ) \times 10 ^ { 8 } M _ { \sun } for NGC 4281 , ( 6.8 \pm 2.0 ) \times 10 ^ { 7 } M _ { \sun } for NGC 4570 and ( 3.2 \pm 0.8 ) \times 10 ^ { 8 } M _ { \sun } for NGC 7049 at 3 \sigma confidence level , which are consistent with recent M _ { BH } - \sigma _ { e } scaling relations .
NGC 3640 has a velocity dispersion dip and NGC 7049 a constant velocity dispersion in the center , but we can clearly constrain their lower black hole mass limit .
We conclude our analysis with a test on NGC 4570 taking into account a variable mass-to-light ratio ( M/L ) when constructing dynamical models .
When considering M/L variations linked mostly to radial changes in the stellar metallicity , we find that the dynamically determined black hole mass from NGC 4570 decreases by 30 % .
Further investigations are needed in the future to account for the impact of radial M/L gradients on dynamical modeling .