A submillimetre survey of the kinematics of the Perseus molecular cloud - II. Molecular outflows
Bibliographic record
Abstract
We present a census of molecular outflows across four active regions of star formation in the Perseus molecular cloud (NGC 1333, IC348/HH211, L1448 and L1455), totalling an area of over 1000 arcmin2. This is one of the largest surveys of outflow evolution in a single molecular cloud published to date. We analyse large-scale, sensitive CO J= 3 → 2 data sets from the James Clerk Maxwell Telescope, including new data towards NGC 1333. Where possible we make use of our complementary 13CO and C18O data to correct for the 12CO optical depth and measure ambient cloud properties. Of the 65 submillimetre cores in our fields, we detect outflows towards 45. 24 of these are marginal detections where the outflow's shape is unclear or could be confused with the other outflows. We compare various parameters between the outflows from Class 0 and I protostars, including their mass, momentum, energy and momentum flux. Class 0 outflows are longer, faster, more massive and have more energy than Class I outflows. The dynamical time-scales we derive from these outflows are uncorrelated to the age of the outflow driving source, computed from the protostar's bolometric temperature. We confirm the results of Bontemps et al. that outflows decrease in force as they age. There is a decrease in momentum flux from the Class 0 to I stage: 〈FCO〉= (0.8 ± 0.3) × 10−4 compared to (1.1 ± 0.3) × 10−5 M⊙ km s−1 yr−1, suggesting a decline in the mass accretion rate assuming the same entrainment fraction for both classes of outflow. If Frad=Lbol/c is the flux expected in radiation from the central source, then FCO(Class I) ∼ 100Frad and FCO(Class 0) ∼ 1000Frad. Furthermore, we confirm there are additional sources of mass loss from protostars. If a core's mass is only lost from outflows at the current rate, cores would endure a few million years, much longer than current estimates for the duration of the protostellar stage. Finally, we note that the total energy contained in outflows in NGC 1333, L1448 and L1455 is greater than the estimated turbulent energy in the respective regions, which may have implications for the regions’ evolution.
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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 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".