A Possible Additional Formation Pathway for the Interstellar Diatomic SiS
Name
Fortenberry_2024_ApJ_971_101.pdf
Description
Published version
Size
337.92 KB
Format
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Checksum (MD5)
604f2e5162864f724ee563d3958eb74c
Author(s)
Fortenberry, Ryan C
McGuire, Brett A
Date Issued
August 8, 2024
Journal
The Astrophysical Journal
Publisher
American Astronomical Society
Citation
Ryan C. Fortenberry and Brett A. McGuire 2024 ApJ 971 101
Version
Final published version
Abstract
The formation of silicon monosulfide (SiS) in space appears to be a difficult process, but the present work shows that a previously excluded pathway may contribute to its astronomical abundance. Reaction of the radicals SH + SiH produces SiS with a submerged transition state and generates a stabilizing H2 molecule as a product to dissipate the kinetic energy. Such is a textbook chemical reaction for favorable gas-phase chemistry. While previously proposed mechanisms reacting atomic sulfur and silicon with SiH, SH, and H2S will still be major contributors to the production of SiS, an abundance of SiS in certain regions could be a marker for the presence of SiH where it has previously been unobserved. These quantum chemically computed reaction profiles imply that the silicon-chalcogen chemistry of molecular clouds, shocked regions, or protoplanetary disks may be richer than previously thought. Quantum chemical spectral data for the intermediate cis- and trans-HSiSH are also provided to aid in their potential spectroscopic characterization.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.3847/1538-4357/ad4d94
