IONIZED NITROGEN AT HIGH REDSHIFT
Bibliographic record
Abstract
We present secure [N ii ] 205 μm detections in two millimeter-bright, strongly lensed objects at high redshift, APM 08279+5255 ( z = 3.911) and MM 18423+5938 ( z = 3.930), using the IRAM Plateau de Bure Interferometer. Due to its ionization energy [N ii ] 205 μm is a good tracer of the ionized gas phase in the interstellar medium. The measured fluxes are S ([N ii ] 205 μm ) = (4.8 ± 0.8) Jy km s −1 and (7.4 ± 0.5) Jy km s −1 , respectively, yielding line luminosities of L ([N ii ] 205 μm ) = (1.8 ± 0.3) × 10 9 μ −1 L ☉ for APM 08279+5255 and L ([N ii ] 205 μm ) = (2.8 ± 0.2) × 10 9 μ −1 L ☉ for MM 18423+5938. Our high-resolution map of the [N ii ] 205 μm and 1 mm continuum emission in MM 18423+5938 clearly resolves an Einstein ring in this source and reveals a velocity gradient in the dynamics of the ionized gas. A comparison of these maps with high-resolution EVLA CO observations enables us to perform the first spatially resolved study of the dust continuum-to-molecular gas surface brightness (Σ FIR ∝Σ N CO , which can be interpreted as the star formation law) in a high-redshift object. We find a steep relation ( N = 1.4 ± 0.2), consistent with a starbursting environment. We measure a [N ii ] 205 μm /FIR luminosity ratio in APM 08279+5255 and MM 18423+5938 of 9.0 × 10 −6 and 5.8 × 10 −6 , respectively. This is in agreement with the decrease of the [N ii ] 205 μm /FIR ratio at high FIR luminosities observed in local galaxies.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".