The Extended Baryon Oscillation Spectroscopic Survey: Measuring the Cross-correlation between the Mg ii Flux Transmission Field and Quasars and Galaxies at z = 0.59
Bibliographic record
Abstract
Abstract We present the first attempt at measuring the baryonic acoustic oscillations (BAOs) in the large-scale cross-correlation between the magnesium-II doublet (Mg ii) flux transmission field and the position of quasar and galaxy tracers. The Mg ii flux transmission continuous field at 0.3 < z < 1.6 is measured from 500,589 quasar spectra obtained in the Baryonic Oscillation Spectroscopic Survey (BOSS) and the extended BOSS (eBOSS). The positions of 246,697 quasar tracers and 1346,776 galaxy tracers are extracted from the Sloan Digital Sky Survey I and II, BOSS, and eBOSS catalogs. In addition to measuring the cosmological BAO scale and the biased matter density correlation, this study allows tests and improvements to cosmological Lyα analyses. A feature consistent with that of the BAOs is detected at a significance of Δχ 2 = 7.25. The measured Mg ii linear transmission bias parameters are b Mg ii(2796) (z = 0.59) = (−6.82 ± 0.54) × 10−4 and b Mg ii(2804) (z = 0.59) = (−5.55 ± 0.46) ×10−4, and the Mg i bias is b Mg i(2853) (z = 0.59) = (−1.48 ± 0.24) × 10−4. Their redshift evolution is characterized by the power-law index: γ Mg = 3.36 ± 0.46. These measurements open a new window toward using BAOs from flux transmission at z < 1 in the final eBOSS sample and in the upcoming sample from the Dark Energy Spectroscopic Instrument.
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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 | 0.000 | 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".