<i>JWST</i> photometry of globular cluster populations in Abell 2744 at <i>z</i> = 0.3
Bibliographic record
Abstract
ABSTRACT JWST imaging of the rich galaxy cluster Abell 2744 at z = 0.308 has been used by the UNCOVER team to construct mosaic images in the NIRCam filters. The exceptionally deep images in the (F115W, F150W, and F200W) bands reveal a large population of unresolved point-like sources across the field, the vast majority of which are globular clusters (GCs) or ultra-compact dwarfs. To the limits of our photometry, more than 10 000 such objects were measured, most of which are in the haloes of the five largest A2744 galaxies but which also include GCs around some satellite galaxies and throughout the intergalactic medium. The measured luminosity function covers almost 4 mag and follows a classic lognormal shape, though the GCLF turnover point still lies fainter than the photometric completeness limit. The colour index (F115W–F200W) in particular covers an intrinsic spread of 0.5 mag, clearly resolving the expected range of GC metallicities. The overall results are consistent with a large, normal GC population seen at a 3.5 Gyr earlier stage of dynamical evolution.
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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 | 0.003 | 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) | 0.003 | 0.001 |
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".