The Rotating Molecular Core and Precessing Outflow of the Young Stellar Object Barnard 1c
Bibliographic record
Abstract
We investigate the structure of the core surrounding the recently identified deeply embedded young stellar object Barnard 1c. B1c lies within the Perseus molecular cloud at a distance of 250 pc. It is a deeply embedded core of 2.4 M ☉ (Kirk et al.) and a luminosity of 4 ± 2 L ☉ . Observations (and resolutions) of 12 CO J = 1-0 (9 2 × 5 9), 13 CO J = 1-0, C 18 O J = 1-0 (14 3 × 6 7), HCO + J = 1-0 (7 6 × 5 8), and N 2 H + J = 1-0 (5 9 × 4 6) were obtained with the BIMA array, together with the continuum at 3.3 mm (6 4 × 4 9) and 2.7 mm (9 5 × 6 3). Single-dish measurements of N 2 H + J = 1-0 and HCO + J = 1-0 with FCRAO reveal the larger scale emission in these lines with ~60 resolution. The 12 CO and HCO + emission traces the outflow extending over the full field of view (2 1), which coincides in detail with the S-shaped jet recently found in Spitzer IRAC imaging. The N 2 H + emission, which anticorrelates spatially with the C 18 O emission, originates from a rotating envelope with effective radius ~2400 AU and mass 2.1-2.9 M ☉ , as derived from the 3.3 mm continuum emission. N 2 H + emission is absent from a 600 AU diameter region around the young star, offset from the continuum peak. The remaining N 2 H + emission may lie in a coherent torus of dense material. With its outflow and rotating envelope, B1c closely resembles the previously studied object L483 mm, and we conclude that it is a protostar in an early stage of evolution, i.e., Class 0 or in transition between Class 0 and Class I. We hypothesize that heating by the outflow and star has desorbed CO from grains, which has destroyed N 2 H + in the inner region, and surmise that the presence of grains without ice mantles in this warm inner region can explain the unusual polarization signature observed from B1c.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".