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

VL - 670

SP - 105

EP - 115

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -