The vertical force in the solar neighbourhood using red clump stars in TGAS and RAVE
Bibliographic record
Abstract
Aims. We investigate the kinematics of red clump (RC) stars in the solar neighbourhood by combining data from Tycho-Gaia Astrometric Solution (TGAS) and Radial Velocity Experiment (RAVE) to constrain the local dark matter density. Methods. After calibrating the absolute magnitude of RC stars, we characterized their velocity distribution over a radial distance range of 6−10 kpc and up to 1.5 kpc away from the Galactic plane. We then applied the axisymmetric Jeans equations on subsets representing the thin and thick disks to determine the (local) distribution of mass near the disk of our Galaxy. Results. Our kinematic maps are well behaved, permitting a straightforward local determination of the vertical force, which we find to be Kzthin = − 2454 ± 619 (km s−1)2 kpc−1 and Kzthick = − 2141 ± 774 (km s−1)2 kpc−1 at 1.5 kpc away from the Galactic plane for the thin and thick disk samples and for thin and thick disk scale heights of 0.28 kpc and 1.12 kpc, respectively. These measurements can be translated into a local dark matter density ρDM ~ 0.018 ± 0.002 M⊙ pc−3. The systematic error on this estimate is much larger than the quoted statistical error, since even a 10% difference in the scale height of the thin disk leads to a 30% change in the value of ρDM and a nearly equally good fit to the data.
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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 | 0.001 |
| 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 | 0.001 | 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".