Laboratory Rotational Spectroscopy Leads to the First Interstellar Detection of Singly Deuterated Methyl Mercaptan (CH<sub>2</sub>DSH)
Bibliographic record
Abstract
Abstract We report an extensive rotational spectroscopic analysis of singly deuterated methyl mercaptan (CH 2 DSH) using both millimeter and far-infrared synchrotron spectra to achieve a global torsional analysis of the three lowest torsional substates ( e 0 , e 1 , and o 1 ) of this nonrigid species. A fit including 3419 millimeter-wave transitions along with 43 infrared torsional subband centers was performed with rms deviations of 0.233 MHz and 0.270 cm −1 , respectively, resulting in 68 fit parameters. A spectroscopic catalog built from this analysis for a temperature of 125 K has led to the first interstellar detection of CH 2 DSH toward the solar-like protostar IRAS 16293-2422 B. We report the identification of 46 transitions, including eight relatively unblended lines, resulting in a derived column density of (3.0 ± 0.3) × 10 14 cm −2 . The column density ratio for HDCS/CH 2 DSH compared to HDCO/CH 2 DOH suggests a difference in the interstellar chemistry between the sulfur and oxygen complex organics, in particular a different link between H 2 CO and CH 3 OH and between H 2 CS and CH 3 SH. This is the first interstellar detection of a deuterated sulfur-bearing complex organic molecule and therefore an important step toward understanding the chemical origin of sulfur-based prebiotics.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".