FAUST – XXVII. The circumbinary disc and the outflow of the L 1551 IRS 5 binary system
Bibliographic record
Abstract
ABSTRACT Using continuum and $\mbox{C}^{18}\mbox{O}\:(2-1)$ line data obtained from the large ALMA (Atacama Large Millimeter/submillimeter Array) programme FAUST (Fifty AU STudy of the chemistry in the disc/envelope system of solar-like protostars), we studied the structure of the protostellar binary system L 1551 IRS 5 at scales between 30 and 3000 au to constrain its properties, from the circumstellar and circumbinary discs up to the envelope and outflow scales, which exhibits complex and entangled structures at the scales of its inner and outer envelopes, presumably caused by the influence of the central binary. Assuming a dust-to-gas ratio of 100, we calculated the dust + gas mass for the circumbinary disc and each circumstellar disc of the binary, obtaining 0.018 M$_\odot$ for the circumbinary disc, 0.004 and 0.002 M$_\odot$ for the northern and southern circumstellar disc, respectively. From the line emission, we retrieved the gas masses for each structure component. With the $\mbox{C}^{18}\mbox{O}\:(2-1)$ position–velocity diagram along the circumbinary disc, we were able to constrain the centrifugal barrier, ${r_{CB}=55}$ au, update the specific angular momentum, ${j\sim 270}$ au km s$^{-1}$. We built an analytical model that can be used to predict the influence of the morphology of the outflow and a few dynamic features that can reproduce the system emission, allowing us to explain and discern the outflow contribution from the complex emission due to the binary. Additionally, we inferred the density power-law index, ${\alpha =1.7}$, and the envelope rotation velocity, $\upsilon _{c}=2$ km s$^{-1}$. Finally, the observations gave us the physical constraints to obtain a coherent outflow model for L 1551 IRS 5.
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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".