M31 Globular Clusters in the [ITAL]HUBBLE SPACE TELESCOPE[/ITAL][ITAL]Hubble Space Telescope[/ITAL] Archive. I. Cluster Detection and Completeness
Bibliographic record
Abstract
Globular clusters at the distance of M31 have apparent angular sizes of a few arcseconds. While many M31 globular clusters have been detected and studied from ground-based images, the high spatial resolution of the Hubble Space Telescope ( HST ) allows much more robust detection and characterization of star cluster properties. We present the results of a search of 157 HST Wide Field Planetary Camera 2 images of M31. We found 82 previously cataloged globular cluster candidates, as well as 32 new globular cluster candidates and 20 open cluster candidates. We present images of the new candidates and photometry for all clusters. We assess existing cluster catalogs' completeness and use the results to estimate the total number of globular clusters in M31 as 460 ± 70. The specific frequency is S N = 1.2 ± 0.2 and the mass specific frequency T = 2.4 ± 0.4; these values are at the upper end of the range seen for spiral galaxies.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.005 | 0.008 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.058 | 0.054 |
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".