Extra-tidal structures around the <i>Gaia Sausage</i> candidate globular cluster NGC 6779 (M56)
Bibliographic record
Abstract
We present results on the stellar density radial profile of the outer regions of NGC 6779, a Milky Way globular cluster recently proposed as a candidate member of the Gaia Sausage structure, a merger remnant of a massive dwarf galaxy with the Milky Way. Taking advantage of the Pan-STARRS PS1 public astrometric and photometric catalogue, we built the radial profile for the outermost cluster regions using horizontal branch and main-sequence stars, separately, in order to probe for different profile trends because of difference stellar masses. Owing to its relatively close location to the Galactic plane, we have carefully treated the chosen colour–magnitude regions properly correcting them by the amount of interstellar extinction measured along the line of side of each star, as well as cleaned them from the variable field star contamination observed across the cluster field. In the region spanning from the tidal to the Jacobi radii, the resulting radial profiles show a diffuse extended halo with an average power-law slope of −1. While analysing the relationships between the Galactocentric distance, the half-mass density, the half-light radius, the slope of the radial profile of the outermost regions, the internal dynamical evolutionary stage, among others, we found that NGC 6779 shows structural properties similar to those of the remaining Gaia Sausage candidate globular clusters, namely, they are massive clusters (>105 M⊙) in a moderately early dynamical evolutionary stage, with observed extra-tidal structures.
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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 | 0.000 | 0.000 |
| 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".