Low-Luminosity Active Galaxies and Their Central Black Holes
Bibliographic record
Abstract
Central black hole masses for 117 spiral galaxies representing morphological stages S0/a through Sc and taken from the large spectroscopic survey of Ho et al. are derived using K s -band data from the Two Micron All Sky Survey. Black hole masses are found using a calibrated black hole- K s bulge luminosity relation, while bulge luminosities are measured by means of a two-dimensional bulge-disk decomposition routine. The black hole masses are correlated against a variety of parameters representing properties of the nucleus and host galaxy. Nuclear properties such as line width (FWHM [N II]), as well as emission-line ratios (e.g., [O III]/Hβ, [O I]/Hα, [N II]/Hα, and [S II]/Hα), show a very high degree of correlation with black hole mass. The excellent correlation with line width supports the view that the emission-line gas is in virial equilibrium with either the black hole or bulge potential. The very good emission-line ratio correlations may indicate a change in ionizing continuum shape with black hole mass in the sense that more massive black holes generate harder spectra. Apart from the inclination-corrected rotational velocity, no excellent correlations are found between black hole mass and host galaxy properties. Significant differences are found between the distributions of black hole masses in early-, mid-, and late-type spiral galaxies (subsamples A, B, and C) in the sense that early-type galaxies have preferentially larger central black holes, consistent with observations that Seyfert galaxies are found preferentially in early-type systems. The line width distributions show a marked difference among subsamples A, B, and C in the sense that earlier type galaxies have larger line widths. There are also clear differences in line ratios between subsamples A+B and C that likely are related to the level of ionization in the gas. Finally, a K s -band Simien & de Vaucouleurs diagram shows excellent agreement with the original B -band relation, although there is a large dispersion at a given morphological stage.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
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".