Near-Infrared Adaptive Optics Imaging of the Central Regions of Nearby S[CLC]c[/CLC] Galaxies. I. M33
Bibliographic record
Abstract
Near-infrared images obtained with the Canada-France-Hawaii Telescope (CFHT) Adaptive Optics Bonnette (AOB) are used to investigate the stellar content within 18'' of the center of the Local Group spiral galaxy M33. Asymptotic giant branch (AGB) stars with near-infrared spectral energy distributions similar to those of giants in the solar neighborhood and Baade's window are detected over most of the field. Neither the peak brightness nor the color of the AGB sequence on the ( K , J - K ) color-magnitude diagram changes with distance from the galaxy center. The bolometric luminosity function (LF) of these stars has a discontinuity near M bol = -5.25, and comparisons with evolutionary tracks suggest that most of the AGB stars formed in a burst of star formation 1–3 Gyr in the past, indicating that the star formation rate near the center of M33 has varied significantly during the past few Gyr. The images are also used to investigate the integrated near-infrared photometric properties of the nucleus and the surrounding central light concentration. The nucleus is bluer than the central light concentration, in agreement with previous studies at visible wavelengths. The near-infrared photometric properties of the nucleus are reminiscent of relatively young clusters in the Magellanic Clouds, while the photometric properties of the central light concentration are similar to those of globular clusters. The CO index of the central light concentration 0 5 from the galaxy center is 0.05, which corresponds to [Fe/H] ∼ -1.2 for simple stellar systems. Hence, the central light concentration could not have formed from the chemically enriched material that dominates the present-day inner disk of M33.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".