My work on SMBHs takes up most of my life right now. The work I do in this area is frequently as a part of the Nuker collaboration (PI Doug Richstone).
- Is There a Black Hole in NGC 4382?
- Orbit Based Dynamical Models of the Sombreo Galaxy
- X-Ray and Radio Constraints on the Mass of the Black Hole in Swift J164449.3+573451
- Observational Selection Effects and the M-σ Relation
- The Black Hole Mass in M87 from Gemini/NIFS Adaptive Optics Observations
- A Distinctive Disk-Jet Coupling in the Seyfert-1 Active Galactic Nucleus NGC 4051
- The Fundamental Plane of Black Hole Accretion
- The Intrinsic Scatter in Black Hole Scaling Relations
- Five Black Hole Mass Measurements.
The Fundamental Plane of Accretion onto Black Holes with Dynamical Masses
(2009c), Fundamental Plane of Accretion onto Black Holes with Dynamical Masses ApJ, 706, 404.
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Black hole accretion and jet production are areas of intensive study in astrophysics. Recent work has found a relation between radio luminosity, X-ray luminosity, and black hole mass. With the assumption that radio and X-ray luminosities are suitable proxies for jet power and accretion power, respectively, a broad fundamental connection between accretion and jet production is implied. In an effort to refine these links and enhance their power, we have explored the above relations exclusively among black holes with direct, dynamical mass-measurements. This approach not only eliminates systematic errors incurred through the use of secondary mass measurements, but also effectively restricts the range of distances considered to a volume-limited sample. Further, we have exclusively used archival data from the Chandra X-ray Observatory to best isolate nuclear sources. We find log LR = (4.80 ± 0.24) + (0.78 ± 0.27)log M BH + (0.67 ± 0.12)log LX , in broad agreement with prior efforts. Owing to the nature of our sample, the plane can be turned into an effective mass predictor. When the full sample is considered, masses are predicted less accurately than with the well-known M-σ relation. If obscured active galactic nuclei are excluded, the plane is potentially a better predictor than other scaling measures.

The M–σ and M–L Relations in Galactic Bulges, and Determinations of Their Intrinsic Scatter
(2009b), The M–σ and M–L Relations in Galactic Bulges, and Determinations of Their Intrinsic Scatter ApJ, 698, 198.
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We derive improved versions of the relations between supermassive black hole mass (MBH) and host-galaxy bulge velocity dispersion (σ) and luminosity (L; the M–σ and M–L relations), based on 49 MBH measurements and 19 upper limits. Particular attention is paid to recovery of the intrinsic scatter (ε0) in both relations. We find log(MBH / M⊙) = α + β * log(σ / 200 km/s) with (α, β, ε0) = (8.12 ± 0.08, 4.24 ± 0.41, 0.44 ± 0.06) for all galaxies and (α, β, ε0) = (8.23 ± 0.08, 3.96 ± 0.42, 0.31 ± 0.06) for ellipticals. The results for ellipticals are consistent with previous studies, but the intrinsic scatter recovered for spirals is significantly larger. The scatter inferred reinforces the need for its consideration when calculating local black hole mass function based on the M-sigma relation, and further implies that there may be substantial selection bias in studies of the evolution of the M–σ relation. We estimate the M–L relationship as log(MBH / M⊙) = α + β * log(LV / 1011 L⊙,V) of (α, β, ε0) = (8.95 ± 0.11, 1.11 ± 0.18, 0.38 ± 0.09); using only early-type galaxies. These results appear to be insensitive to a wide range of assumptions about the measurement errors and the distribution of intrinsic scatter. We show that culling the sample according to the resolution of the black hole’s sphere of influence biases the relations to larger mean masses, larger slopes, and incorrect intrinsic residuals.

A Quintet of Black Hole Mass Determinations
(2009a), A Quintet of Black Hole Mass Determinations ApJ, 695, 1577.
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We report five new measurements of central black hole masses based on
Space Telescope Imaging Spectrograph (STIS) and Wide Field Planetary Camera 2
(WFPC2) observations with the Hubble Space Telescope (HST)
and on
axisymmetric, three-integral, Schwarzschild orbit-library kinematic
models. We selected a sample of galaxies within a narrow range in
velocity dispersion that cover a range of galaxy parameters (including
Hubble type and core/power-law surface density profile) where we
expected to be able to resolve the galaxy’s sphere of influence
based on the predicted value of the black hole mass from the
M–σ relation. We find masses for the following
galaxies:
NGC 3607, MBH = 1.2 (+0.4, -0.4) × 108 M⊙;
NGC 4026, MBH = 2.1 (+0.7, -0.4) × 108 M⊙; and
NGC 5576, MBH = 1.8 (+0.3, -0.4) × 108 M⊙,
all significantly excluding MBH = 0. For
which is significantly below predictions from M–σ and M–L relations and consistent with MBH = 0, though the presence of a double bar in this galaxy may present problems for our axisymmetric code.

