The Black hole mass of NGC 4151: comparison of reverberation mapping and stellar dynamical measurements
Date
2007-11-20Author
Onken, Christopher
Valluri, Monica
Peterson, Bradley
Pogge, Richard
Bentz, Misty
Ferrarese, Laura
Vestergaard, Marianne
Crenshaw, Michael
Sergeev, Sergey
McHardy, Ian
Merritt, David
Bower, Gary
Heckman, Timothy
Wandel, Amri
Metadata
Show full item recordAbstract
We present a stellar dynamical estimate of the black hole (BH) mass in the Seyfert 1
galaxy, NGC 4151. We analyze ground-based spectroscopy as well as imaging data
from the ground and space, and we construct 3-integral axisymmetric models in order
to constrain the BH mass and mass-to-light ratio. The dynamical models depend on
the assumed inclination of the kinematic symmetry axis of the stellar bulge. In the
case where the bulge is assumed to be viewed edge-on, the kinematical data give only
an upper limit to the mass of the BH of ∼ 4 × 107 M⊙ (1 ). If the bulge kinematic
axis is assumed to have the same inclination as the symmetry axis of the large-scale
galaxy disk (i.e., 23◦ relative to the line of sight), a best-fit dynamical mass between
4 − 5 × 107 M⊙ is obtained. However, because of the poor quality of the fit when the
bulge is assumed to be inclined (as determined by the noisiness of the 2 surface and
its minimum value), and because we lack spectroscopic data that clearly resolves the
BH sphere of influence, we consider our measurements to be tentative estimates of the
dynamical BH mass. With this preliminary result, NGC 4151 is now among the small
sample of galaxies in which the BH mass has been constrained from two independent
techniques, and the mass values we find for both bulge inclinations are in reasonable
agreement with the recent estimate from reverberation mapping (4.57+0.57
−0.47 × 107 M⊙)
published by Bentz et al.