ALMA observations of acetone in hot cores
Year: 2026
Type: article
Abstract: ABSTRACT Acetone (CH$_3$COCH$_3$) is a ubiquitous interstellar molecule and serves as an important tracer of hot core chemistry. We conducted a line survey of acetone and its precursor acetaldehyde (CH$_3$CHO) towards 60 hot cores by using the ALMA (Atacama Large Millimeter/submillimeter Array) 3 mm lines observations. We calculated the rotational temperatures and column densities of acetone using the xclass software. Acetone was detected in 15 hot cores with rotational temperatures ranging from 89 to 176 K. Its column densities range from (0.9–24) $\times$ 10$^{16}$ cm$^{-2}$. The spatial distributions of acetone exhibit similarities with those of acetaldehyde. The emissions of acetone are concentrated towards the hot core regions and generally exhibit a compact spatial distribution, whereas the emission of acetaldehyde shows a more extended spatial profile. Combined with previous studies, we found a moderately positive correlation between the column densities and rotational temperatures of acetone for the high-mass hot cores ($r = 0.59$). We also found a strong positive correlation between the column densities of acetone and acetaldehyde ($r= 0.82$), indicating a chemical relationship between them. By comparing these observational results with the three-phase model results, we found that the models overpredict the ratio of acetone to methanol relative to the observational data. This discrepancy suggests that current chemical networks may inadequately account for acetone destruction pathways or potential missing physical conditions in the model. Therefore, our large sample observations can provide constraints on chemical models and reinforce the role of acetone as a tracer of complex organic chemistry in warm, dense regions.
Authors: Xia Zhang, Xiaohu Li, Zhiping Kou
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
Funders: National Science Foundation, U.S. Nuclear Regulatory Commission, Natural Science Foundation of Xinjiang Province, National Radio Astronomy Observatory, Associated Universities, European School of Oncology, National Natural Science Foundation of China, Chinese Academy of Sciences, Alberta Livestock and Meat Agency, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, National Institutes of Natural Sciences
OpenAlex ID: W7155350980