Tentative Detection of FeS toward Orion SrcI
Abstract
Iron sulfide (FeS) is a key refractory compound in astrophysical environments. It is commonly found in meteorites and evidence of FeS has only been reported in solid form in a protoplanetary environment. Furthermore, FeS is of astrobiological interest since it acts as a precursor to the formation of pyrite (FeS2), which plays a key role in anaerobic metabolism. We present millimeter-wave spectroscopic calculations for gaseous FeS and report its tentative detection toward the massive disk Orion SrcI. If confirmed, this would constitute the first ever detection of gaseous FeS in the interstellar medium. Our data are consistent with a FeS column density of ∼1.7 × 1015 cm−2. Comparing to other sulfur reservoirs, the amount of sulfur locked in FeS is more than three orders of magnitude lower than that contained in SO2 and SiS. However, FeS emission may arise from a different region as it is the case for the metallic salt NaCl. Our results support the presence of FeS in interstellar grains and are consistent with grain destruction playing an important role in the origin of the FeS emission. The observations, however, are still insufficient to discern whether FeS is a main sulfur reservoir in molecular clouds or a primary carrier of refractory iron-bearing material.
Versions
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BibTeX
@misc{tasachaveli2026tentative,
title = {{Tentative Detection of FeS toward Orion SrcI}},
author = {Aitana Tasa-Chaveli and Holger S. P. Müller and Álvaro Sánchez-Monge and Asunción Fuente and Adam Ginsburg and Thomas Möller},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.06346},
eprint = {2610.06346},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.06346},
note = {CC BY-SA 4.0},
}
RIS
TY - UNPB
TI - Tentative Detection of FeS toward Orion SrcI
AU - Aitana Tasa-Chaveli
AU - Holger S. P. Müller
AU - Álvaro Sánchez-Monge
AU - Asunción Fuente
AU - Adam Ginsburg
AU - Thomas Möller
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.06346
UR - https://arxiv.org/abs/2610.06346
AB - Iron sulfide (FeS) is a key refractory compound in astrophysical environments. It is commonly found in meteorites and evidence of FeS has only been reported in solid form in a protoplanetary environment. Furthermore, FeS is of astrobiological interest since it acts as a precursor to the formation of pyrite (FeS_2), which plays a key role in anaerobic metabolism. We present millimeter-wave spectroscopic calculations for gaseous FeS and report its tentative detection toward the massive disk Orion SrcI. If confirmed, this would constitute the first ever detection of gaseous FeS in the interstellar medium. Our data are consistent with a FeS column density of ∼1.7 × 10^15 cm^−2. Comparing to other sulfur reservoirs, the amount of sulfur locked in FeS is more than three orders of magnitude lower than that contained in SO_2 and SiS. However, FeS emission may arise from a different region as it is the case for the metallic salt NaCl. Our results support the presence of FeS in interstellar grains and are consistent with grain destruction playing an important role in the origin of the FeS emission. The observations, however, are still insufficient to discern whether FeS is a main sulfur reservoir in molecular clouds or a primary carrier of refractory iron-bearing material.
ER -