Gemini GNIRS Near-infrared Spectroscopy of 50 Quasars at z ≳ 5.7
Bibliographic record
Abstract
Abstract We report initial results from a large Gemini program to observe z ≳ 5.7 quasars with GNIRS near-IR spectroscopy. Our sample includes 50 quasars with simultaneous ∼0.85–2.5 μ m spectra covering the rest-frame ultraviolet and major broad emission lines from Lyα to Mg ii . We present spectral measurements for these quasars and compare with their lower redshift counterparts at z = 1.5–2.3. We find that when quasar luminosity is matched, there are no significant differences between the rest-UV spectra of z ≳ 5.7 quasars and the low- z comparison sample. High- z quasars have similar continuum and emission line properties and occupy the same region in the black hole mass and luminosity space as the comparison sample, accreting at an average Eddington ratio of ∼0.3. There is no evidence for super-Eddington accretion or hypermassive (>10 10 M ⊙ ) black holes within our sample. We find a mild excess of quasars with weak C iv lines relative to the control sample. Our results, corroborating earlier studies but with better statistics, demonstrate that these high- z quasars are already mature systems of accreting supermassive black holes operating with the same physical mechanisms as those at lower redshifts.
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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 | 0.000 |
| 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".