Astrochemistry

The Missing Link of Sulfur Chemistry in TMC-1: The Detection of c-C3H2S from the GOTHAM Survey

By Keith Cowing
Press Release
January 14, 2025
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The Missing Link of Sulfur Chemistry in TMC-1: The Detection of c-C3H2S from the GOTHAM Survey
Velocity stacked and matched filter spectra of c-C3H2S. The intensity scales are the signal-to-noise ratios (SNR) of the response functions when centered at a given velocity. The “zero” velocity corresponds to the channel with the highest intensity to account for blended spectroscopic transitions and variations in velocity component source sizes. (Left ) The stacked spectra from the GOTHAM DRV data are displayed in black, overlaid with the expected line profile in red from our MCMC fit to the data. The SNR is on a per-channel basis. (Right ) Matched filter response obtained from cross-correlating the simulated and observed velocity stacks in the left panel; value annotated corresponds to the peak impulse response of the matched filter. — astro-ph.GA

We present the spectroscopic characterization of cyclopropenethione (c-C3H2S) in the laboratory and detect it in space using the Green Bank Telescope (GBT) Observations of TMC-1: Hunting Aromatic Molecules (GOTHAM) survey.

The detection of this molecule – the missing link in understanding the C3H2S isomeric family in TMC-1 – completes the detection of all 3 low-energy isomers of C3H2S as both CH2CCS and HCCCHS have been previously detected in this source.

The total column density of this molecule (N_T of 5.72+2.65/-1.61×10^10 cm^-2 at an excitation temperature of 4.7+1.3/-1.1 K) is smaller than both CH2CCS and HCCCHS and follows nicely the relative dipole principle (RDP), a kinetic rule-of-thumb for predicting isomer abundances which suggests that, all other chemistry among a family of isomers being the same, the member with the smallest dipole should be the most abundant.

The RDP now holds for the astronomical abundance ratios of both the S-bearing and O-bearing counterparts observed in TMC-1; however, CH2CCO continues to elude detection in any astronomical source.

Anthony J. Remijan, P. Bryan Changala, Ci Xue, Elsa Q.H. Yuan, Miya Duffy, Haley N. Scolati, Christopher N. Shingledecker, Thomas H. Speak, Ilsa R. Cooke, Ryan Loomis, Andrew M. Burkhardt, Zachary T.P. Fried, Gabi Wenzel, Andrew Lipnicky, Michael C. McCarthy, Brett A. McGuire

Comments: 10 Pages, 7 Figures, 11 Tables
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2501.06343 [astro-ph.GA] (or arXiv:2501.06343v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2501.06343
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Submission history
From: Anthony Remijan
[v1] Fri, 10 Jan 2025 20:57:23 UTC (2,114 KB)
https://arxiv.org/abs/2501.06343
Astrobiology,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻