TY - JOUR
T1 - The black hole mass of NGC 4151
T2 - Comparison of reverberation mapping and stellar dynamical measurements
AU - Onken, Christopher A.
AU - Valluri, Monica
AU - Peterson, Bradley M.
AU - Pogge, Richard W.
AU - Bentz, Misty C.
AU - Ferrarese, Laura
AU - Vestergaard, Marianne
AU - Crenshaw, D. Michael
AU - Sergeev, Sergey G.
AU - McHardy, Ian M.
AU - Merritt, David
AU - Bower, Gary A.
AU - Heckman, Timothy M.
AU - Wandel, Amri
PY - 2007/11/20
Y1 - 2007/11/20
N2 - 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 three-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 in which 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 x 107 M⊙ (1 σ). 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 and 5 x 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 x2 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 X 10 7 M⊙) published by Bentz et al.
AB - 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 three-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 in which 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 x 107 M⊙ (1 σ). 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 and 5 x 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 x2 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 X 10 7 M⊙) published by Bentz et al.
KW - Black hole physics
KW - Galaxies: active
KW - Galaxies: nuclei
KW - Galaxies: structure
KW - Stellar dynamics
UR - http://www.scopus.com/inward/record.url?scp=39049167614&partnerID=8YFLogxK
U2 - 10.1086/522220
DO - 10.1086/522220
M3 - Journal article
AN - SCOPUS:39049167614
SN - 0004-637X
VL - 670
SP - 105
EP - 115
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
ER -