A MegaCam Survey of Outer Halo Satellites. VII. A Single Sérsic Index versus Effective Radius Relation for Milky Way Outer Halo Satellites*†
Bibliographic record
Abstract
Abstract In this work, we use structural properties of the Milky Way’s outer halo (R G > 25 kpc) satellites (dwarf spheroidal galaxies, ultra-faint dwarf (UFD) galaxies and globular clusters (GCs)) derived from deep, wide-field, and homogeneous data to present evidence of a correlation in the Sérsic index versus effective radius plane followed by a large fraction of outer halo GCs and satellite dwarf galaxies. We show that this correlation can be entirely reproduced by fitting empirical relations in the central surface brightness versus absolute magnitude and Sérsic index versus absolute magnitude parameter spaces, and by assuming the existence of two types of outer halo GCs: one of high surface brightness (HSB group), with properties similar to those of inner halo clusters; and another of low surface brightness (LSB group), which share characteristics with dwarf spheroidal and UFD galaxies. Given the similarities of LSB clusters with dwarf spheroidal and UFD galaxies, we discuss the possibility that outer halo clusters also originated inside dark matter halos and that tidal forces from different host galaxy potentials are responsible for the different properties between HSB and LSB clusters.
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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 | 0.001 |
| 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 | 0.001 |
| 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".