THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: FIRST BROAD-LINE Hβ AND Mg ii LAGS AT z ≳ 0.3 FROM SIX-MONTH SPECTROSCOPY
Bibliographic record
Abstract
ABSTRACT Reverberation mapping (RM) measurements of broad-line region (BLR) lags in quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of RM in this regime. Here we report preliminary results of 15 BLR lag measurements from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, a dedicated RM program with multi-object spectroscopy designed for RM over a wide redshift range. The lags are based on the 2014 spectroscopic light curves alone (32 epochs over six months) and focus on the H β and Mg ii broad lines in the 100 lowest-redshift ( ) quasars included in SDSS-RM; they represent a small subset of the lags that SDSS-RM (including 849 quasars to ) is expected to deliver. The reported preliminary lag measurements are for intermediate-luminosity quasars at , including nine H β lags and six Mg ii lags, for the first time extending RM results to this redshift–luminosity regime and providing direct quasar black hole mass estimates over approximately half of cosmic time. The Mg ii lags also increase the number of known Mg ii lags by several fold and start to explore the utility of Mg ii for RM at high redshift. The location of these new lags at higher redshifts on the observed BLR size–luminosity relationship is statistically consistent with previous H β results at . However, an independent constraint on the relationship slope at is not yet possible owing to the limitations in our current sample. Our results demonstrate the general feasibility and potential of multi-object RM for quasars.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.002 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".