Collisional excitation of E - and Z -ethanimine to model cold molecular clouds
- 1Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) – UMR 6251
- 2Chemistry Department, Wehr Chemistry Building, Marquette University
- 3Department of Chemistry, Missouri University of Science and Technology
Abstract
Context . Ethanimine is a prebiotically relevant complex organic molecule that has been proposed as a key precursor of amino acids in the interstellar medium. To date, both its E and Z isomers have only been detected toward the Sgr B2(N) molecular cloud. The pronounced non-local thermodynamic equilibrium (non-LTE) effects predicted for this molecule require accurate collisional rate coefficients for reliable astrophysical modeling and future astronomical searches.
Aims . We aim to provide the first collisional datasets for both ethanimine isomers with the main cold molecular clouds collision partners, He and para -H ₂ , in order to support non-LTE radiative-transfer modeling.
Methods . State-to-state rate coefficients for collisions with He were computed by integration over mixed close-coupling (CC) and coupled-states (CS) scattering cross sections at different energy ranges. In addition, comparisons with mixed quantum-classical theory (MQCT) calculations performed for both He and para -H ₂ collisions enabled the derivation of transition-specific scaling factors, which were applied to predict collisional rate coefficients for para -H ₂ .
Results . We present the first state-to-state collisional datasets for both E - and Z -ethanimine in collision with He and para -H ₂ , including all rotational transitions involving levels below 50 cm ⁻¹ and over the 5–100 K temperature range.
Conclusions . The datasets reported here provide the first collisional information suitable for non-LTE modeling of ethanimine in cold interstellar environments. They represent a key step toward more reliable abundance determinations and may facilitate future astronomical detections of both ethanimine isomers beyond Sgr B2(N).
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BibTeX
@article{tonolo2026collisional,
title = {{Collisional excitation of E - and Z -ethanimine to model cold molecular clouds}},
author = {Francesca Tonolo and Vivek Vijay and Ernesto Quintas-Sánchez and Adrian Batista Planas and Carolin Joy and Richard Dawes and François Lique and Dmitri Babikov},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = oct,
doi = {10.1051/0004-6361/202662226},
url = {https://www.aanda.org/10.1051/0004-6361/202662226},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Collisional excitation of E - and Z -ethanimine to model cold molecular clouds
AU - Francesca Tonolo
AU - Vivek Vijay
AU - Ernesto Quintas-Sánchez
AU - Adrian Batista Planas
AU - Carolin Joy
AU - Richard Dawes
AU - François Lique
AU - Dmitri Babikov
PY - 2026
DA - 2026/10/29
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202662226
UR - https://www.aanda.org/10.1051/0004-6361/202662226
AB - Context . Ethanimine is a prebiotically relevant complex organic molecule that has been proposed as a key precursor of amino acids in the interstellar medium. To date, both its E and Z isomers have only been detected toward the Sgr B2(N) molecular cloud. The pronounced non-local thermodynamic equilibrium (non-LTE) effects predicted for this molecule require accurate collisional rate coefficients for reliable astrophysical modeling and future astronomical searches. Aims . We aim to provide the first collisional datasets for both ethanimine isomers with the main cold molecular clouds collision partners, He and para -H ₂ , in order to support non-LTE radiative-transfer modeling. Methods . State-to-state rate coefficients for collisions with He were computed by integration over mixed close-coupling (CC) and coupled-states (CS) scattering cross sections at different energy ranges. In addition, comparisons with mixed quantum-classical theory (MQCT) calculations performed for both He and para -H ₂ collisions enabled the derivation of transition-specific scaling factors, which were applied to predict collisional rate coefficients for para -H ₂ . Results . We present the first state-to-state collisional datasets for both E - and Z -ethanimine in collision with He and para -H ₂ , including all rotational transitions involving levels below 50 cm ⁻¹ and over the 5–100 K temperature range. Conclusions . The datasets reported here provide the first collisional information suitable for non-LTE modeling of ethanimine in cold interstellar environments. They represent a key step toward more reliable abundance determinations and may facilitate future astronomical detections of both ethanimine isomers beyond Sgr B2(N).
SN - 0004-6361
SN - 1432-0746
ER -