Water cooling of shocks in protostellar outflows
Bibliographic record
Abstract
<i>Context. <i/>The far-IR/sub-mm spectral mapping facility provided by the <i>Herschel<i/>-PACS and HIFI instruments has made it possible to obtain, for the first time, images of H<sub>2<sub/>O emission with a spatial resolution comparable to ground based mm/sub-mm observations.<i>Aims. <i/>In the framework of the Water In Star-forming regions with <i>Herschel<i/> (WISH) key program, maps in water lines of several outflows from young stars are being obtained, to study the water production in shocks and its role in the outflow cooling. This paper reports the first results of this program, presenting a PACS map of the o-H<sub>2<sub/>O 179 <i>μ<i/>m transition obtained toward the young outflow L1157.<i>Methods. <i/>The 179 <i>μ<i/>m map is compared with those of other important shock tracers, and with previous single-pointing ISO, SWAS, and Odin water observations of the same source that allow us to constrain the H<sub>2<sub/>O abundance and total cooling. <i>Results. <i/>Strong H<sub>2<sub/>O peaks are localized on both shocked emission knots and the central source position. The H<sub>2<sub/>O 179 <i>μ<i/>m emission is spatially correlated with emission from H<sub>2<sub/> rotational lines, excited in shocks leading to a significant enhancement of the water abundance. Water emission peaks along the outflow also correlate with peaks of other shock-produced molecular species, such as SiO and NH<sub>3<sub/>. A strong H<sub>2<sub/>O peak is also observed at the location of the proto-star, where none of the other molecules have significant emission. The absolute 179 <i>μ<i/>m intensity and its intensity ratio to the H<sub>2<sub/>O 557 GHz line previously observed with Odin/SWAS indicate that the water emission originates in warm compact clumps, spatially unresolved by PACS, having a H<sub>2<sub/>O abundance of the order of 10<sup>-4<sup/>. This testifies that the clumps have been heated for a time long enough to allow the conversion of almost all the available gas-phase oxygen into water. The total H<sub>2<sub/>O cooling is ~10<sup>-1<sup/> , about 40% of the cooling due to H<sub>2<sub/> and 23% of the total energy released in shocks along the L1157 outflow.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".