A Quest for Sulfur-bearing Refractory Species: Identification of CaS in the Interstellar Medium
Year: 2025
Type: article
Abstract: The recent detection of refractory molecules in massive star-forming regions provides a means of probing the innermost regions of disks around massive stars. These detections also make it possible to explore the chemical composition of refractories through gas-phase observations. In this regard, identifying refractory compounds containing sulfur could reveal potential connections between sulfur and refractories, as well as help determine the sulfur budget in these extreme environments. We find convincing evidence of a reliable detection of CaS, and tentative detections of KS and KSH, in the disk G351.77-mm1. These are the first ever identifications of these species in the interstellar medium. The CaS, KS, and KSH column densities are about 3 orders of magnitude lower than those of the abundant sulfur compounds SO 2 , CH 3 SH, and SiS, proving that these species are not the major reservoir of sulfur at the spatial scales probed by our observations. Higher angular resolution observations at different wavelengths are required to confirm these detections, which are of paramount importance to gain insights into the formation of gas-phase refractory molecules.
Institutions: Universidad Complutense de Madrid, Consejo Superior de Investigaciones Científicas, Centro de Astrobiología, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, University of Florida, University of Cologne, Spanish National Observatory, European Space Agency, European Space Astronomy Centre
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,400
Funders: National Science Foundation, National Radio Astronomy Observatory, European Commission, Deutsche Forschungsgemeinschaft, Korea Astronomy and Space Science Institute, Ministerio de Ciencia e Innovación, National Astronomical Observatory of Japan, HORIZON EUROPE Framework Programme, National Institutes of Natural Sciences, European Regional Development Fund, Agencia Estatal de Investigación
Awards: G121809054, G1397962376, G1622782223, G2123792313, G2309174360, G2436430949, G2660406951, G302750986, G3439265645, G3480869486, G3518538256, G4442677895, G4526231891, G464105488, G5080475149, G5934669618, G5950425101, G617610489, G7084143925, G7823692103, SFB 1601: Die kosmische Entwicklung der Lebensräume massereicher Sterne, G8920660035, G897484643
OpenAlex ID: W4415787231