Observations of a curving molecular outflow from V380 Ori-NE: further support for prompt entrainment in protostellar outflows
Bibliographic record
Abstract
CO J = 3–2 and 4–3 observations of V380 Ori-NE reveal a highly collimated bipolar molecular outflow associated with a jet traced here in H2 1–0 S(1) line emission. The source of the flow is also detected at 450 and 850 μm with SCUBA. The combined CO and near-IR observations offer compelling support for the prompt entrainment model of jet-driven molecular outflows. Not only are the H2 shock fronts spatially coincident with peaks in the CO outflow lobes, but the slope of the mass-velocity distribution in the flow, measured here at intervals along both flow lobes, also clearly decreases just behind the advancing shock fronts (and towards the ends of the flow lobes), as one would expect if the high-to-low velocity mass fraction was enhanced by the entraining shocks. We also find that both lobes of the CO outflow clearly deviate, by some 20°, from the H2 jet direction near the source. Both lobes may be being deflected at the locations of the observed H2 shock fronts, where they impact dense, ambient material. Alternatively, the almost point-symmetric CO flow pattern could be caused by precession at the source. The submillimetre (submm) data reveal the source of the outflow, V380 Ori-NE. The 450- and 850-μm maps show an elongated peak superimposed on to an extensive pedestal of weaker emission. The major axis of the source is oriented parallel with the inner flow axis. Indeed, weak 850-μm emission is detected along much of the bipolar outflow, particularly in the southern lobe and towards the southernmost CO intensity peak. The submm ‘continuum’ data therefore probably trace warm dust and CO associated with the outflow. These data also confirm the status of V380 Ori-NE as a Class I protostar. Overall, the orientation, simplicity and symmetry of this outflow, combined with the remarkable strength of the high-velocity line-wing emission in comparison to the ambient emission, make this system a perfect laboratory for future detailed studies of bipolar molecular outflows and their association with collimated jets from young, deeply embedded protostars.
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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".