A MULTI-IONIC KINEMATIC INVESTIGATION OF NGC 595, A GIANT EXTRAGALACTIC H II REGION IN M33
Bibliographic record
Abstract
Spectro-interferometric observations of the Hα, [O iii ], and [S ii ] optical emission lines are combined with radio observations of the 21 cm line in order to obtain a reliable kinematic image of NGC 595, the second largest giant extragalactic H ii region in M33. The Hα and [O iii ] observations reveal that the nebula is exposed to two distinct kinematical regimes. While symmetric, broad velocity profiles dominate a sizeable fraction of the ionized extent, evidence for line splitting is detected in a small region near the most massive stars of the star cluster. A quantitative investigation proposes that two expanding wind-blown bubbles could be held responsible for the observed line splitting. The kinematics of the ionized material presenting one-component velocity profiles likely indicates that Champagne flows are present at the periphery of the molecular component leading to accelerated ionized material in the ambient interstellar medium. In areas not dominated by the photoionization of the molecular clouds, the H + and S + material shows a kinematical behavior roughly in agreement with the atomic gas. Mean nonthermal line widths show relatively large, supersonic values especially in [O iii ]. Models of structure functions indicate that the Hα and [O iii ] components could be exposed to different turbulent motions which could explain the broadening excess observed for the latter ion. On the full ionized extent of the nebula, the S + material shows narrower line widths than the two other ions. Combined with the absence of line splitting, these peculiar characteristics indicate that the [S ii ] component is likely located at the periphery of the nebula and probably does not coexist with Hα and [O iii ]. The shape of the [S ii ] structure function is in agreement with a relatively low number of large-scale velocity gradients which partially explains the narrower profiles observed. The mean electron density in the nebula is estimated at 162 ± 106(1σ) cm −3 , in agreement with previous studies of similar extragalactic H ii regions. We provide the first bidimensional electron density map ever presented for a giant extragalactic nebula.
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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) | 0.000 | 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 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".