The Peculiar Type I[CLC]a[/CLC] Supernova 1999[CLC]by[/CLC]: Spectroscopy at Early Epochs
Bibliographic record
Abstract
We present medium-resolution (λ/Δλ ≈ 2500) optical spectroscopy of SN 1999by in NGC 2841 made around its light maximum. That the depth ratio of the two Si II features at 5800 and 6150 Å are R (Si II) ≈ 0.63 at maximum indicates that this SN belongs to the peculiar subluminous Type SNe Ia. Radial velocities inferred from the minimum of the 6150 Å trough reveal a steeper decline of the velocity curve than expected for normal SNe Ia, consistent with the behavior of published VRI light curves. A revised absolute magnitude of SN 1999by and distance to its host galaxy NGC 2841 are estimated based on the multicolor light-curve shape (MLCS) method, resulting in M V (max) = -18.06 ± 0.1 mag and d = 17.1 ± 1.2 Mpc, respectively. An approximate linear dependence of the luminosity parameter Δ on R (Si II) is presented.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| 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".