WISDOM Project–XXVI. Cross-checking supermassive black hole mass estimates from ALMA CO gas kinematics and SINFONI stellar kinematics in the galaxy NGC 4751
Bibliographic record
Abstract
ABSTRACT We present high angular resolution (0.19 arcsec or $\approx 24$ pc) Atacama Large Millimeter/submillimeter Array observations of the $^{12}$CO(3–2) line emission of the galaxy NGC 4751. The data provide evidence for the presence of a central supermassive black hole (SMBH). Assuming a constant mass-to-light ratio ($M/L$), we infer a SMBH mass $M_\text{BH}=3.43^{+0.45}_{-0.44}[\text{stat},\, 3\sigma ]^{+0.22}_{-0.64}[\text{sys}]\times 10^9$ M$_\odot$ and a F160W filter stellar $M/L_\text{F160W}=2.68\pm 0.11[\text{stat},\, 3\sigma ]^{+0.10}_{-0.80}[\text{sys}]$ M$_\odot$/L$_{\odot ,\text{F160W}}$, where the first uncertainties are statistical and the second systematic. Assuming a linearly spatially varying $M/L$, we infer $M_\text{BH}=2.79^{+0.75}_{-0.57}[\text{stat},\, 3\sigma ]^{+0.75}_{-0.45}[\text{syst}]\times 10^9$ M$_\odot$ and $\left(M/L_\text{F160W}\right)/\left(\text{M}_\odot /\text{L}_{\odot ,\text{F160W}}\right)=3.07^{+0.27}_{-0.35}[\text{stat},\, 3\sigma ]^{+0.08}_{-1.14}[\text{sys}]-0.09^{+0.08}_{-0.06}[\text{stat},\, 3\sigma ]^{+0.08}_{-0.01}[\text{sys}]\, \left(R/\text{arcsec}\right)$, where R is the galactocentric radius. We also present SMBH mass estimates using the Jeans Anisotropic Modelling (JAM) method and Very Large Telescope Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) stellar kinematics. Assuming a cylindrically aligned velocity ellipsoid (JAM$_\text{cyl}$), we infer $M_\text{BH}=(2.52\pm 0.36)\times 10^9$ M$_\odot$, and while assuming a spherically aligned velocity ellipsoid (JAM$_\text{sph}$), we infer $M_\text{BH}=(3.24\pm 0.87)\times 10^9$ M$_\odot$. The SMBH mass assuming a constant $M/L$ is statistically consistent with that of JAM$_\text{sph}$, whereas the mass assuming a linearly varying $M/L$ is consistent with both JAM$_\text{cyl}$ and JAM$_\text{sph}$ (within the uncertainties). Our derived masses are larger than (and inconsistent with) one previous stellar dynamical measurement using the Schwarzschild orbit-superposition method and the same SINFONI kinematics.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.006 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.035 | 0.027 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".