NEW H-BAND STELLAR SPECTRAL LIBRARIES FOR THE SDSS-III/APOGEE SURVEY
Bibliographic record
Abstract
The Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) has obtained high-resolution (R ~ 22,500), high signal-to-noise ratio (\\gt 100) spectra in the H-band (~1.5--1.7 mum) for about 146,000 stars in the Milky Way galaxy. We have computed spectral libraries with effective temperature ({{T}<SUB>eff</SUB>}) ranging from 3500 to 8000 K for the automated chemical analysis of the survey data. The libraries, used to derive stellar parameters and abundances from the APOGEE spectra in the SDSS-III data release 12 (DR12), are based on ATLAS9 model atmospheres and the ASS&epsilon;T spectral synthesis code. We present a second set of libraries based on MARCS model atmospheres and the spectral synthesis code Turbospectrum. The ATLAS9/ASS&epsilon;T ({{T}<SUB>eff</SUB>} = 3500--8000 K) and MARCS/Turbospectrum ({{T}<SUB>eff</SUB>} = 3500--5500 K) grids cover a wide range of metallicity (-2.5 <=slant [M/H] <=slant +0.5 dex), surface gravity (0 <= log g <=slant 5 dex), microturbulence (0.5 <=slant xi <=slant 8 km s<SUP>-1</SUP>), carbon (-1 <=slant [C/M] <=slant +1 dex), nitrogen (-1 <=slant [N/M] <=slant +1 dex), and alpha-element (-1 <=slant [alpha/M] <=slant +1 dex) variations, having thus seven dimensions. We compare the ATLAS9/ASS&epsilon;T and MARCS/Turbospectrum libraries and apply both of them to the analysis of the observed H-band spectra of the Sun and the K2 giant Arcturus, as well as to a selected sample of well-known giant stars observed at very high resolution. The new APOGEE libraries are publicly available and can be employed for chemical studies in the H-band using other high-resolution spectrographs.
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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 | 0.001 | 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 | 0.001 | 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".