Thermodynamics of the H <scp>ii</scp> Region Sh2-158 and “Direct” Measurement of Its Turbulence
Bibliographic record
Abstract
Abstract Three SITELLE hyperspectral cubes were used to obtain 12 million spectra sampling 11 emission lines of the H ii region Sh2-158. This data set enables the calculation of numerous diagnostics and physical parameters such as abundance, electronic density, temperature, and pressure. The thermodynamic study of the nebula revealed interesting results. From [S ii] and [N ii] line ratio diagnostics, electronic density and temperature maps were calculated by an iterative computation method. A Monte Carlo analysis was implemented to determine accurate uncertainties for all physical parameters. We thus measured median electronic density and temperature values of 370 cm−3 and 7020 K from the iterative maps. Examining the global maps and the sampled subregions, complex patterns of density and temperature gradients/variations are observed. We produce an electronic pressure map that shows diminishing pressure, a factor of 10, from the molecular cloud to the outskirts of Sh2-158. Fabry–Perot observations complete the data to further the dynamical analysis of Sh2-158. Supersonic turbulent velocities are “directly” measured from the [N ii] 6584 Å. Three statistical tools are used to analyze velocity centroid and nonthermal linewidth maps. The analysis of the velocity fluctuations shows the presence of intermittency. This phenomenon can produce the temperature fluctuations that are suggested to explain the abundance discrepancy problem in H ii regions.
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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 | 0.000 | 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".