E-和Z-乙亚胺的碰撞激发以模拟冷分子云
Collisional excitation of E- and Z-ethanimine to model cold molecular clouds
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中文总结 AI 辅助
本研究为E-和Z-乙亚胺与He及para-H2的碰撞提供首个态到态速率系数数据集，支持冷分子云中的non-LTE辐射转移建模，促进丰度测定和未来天文探测。
中文摘要 AI 辅助
背景。乙亚胺是一种具有前生物意义的复杂有机分子，已被提出作为星际介质中氨基酸的关键前体。迄今为止，其E和Z两种异构体仅在Sgr B2(N)分子云中被探测到。预测该分子存在显著的非局部热力学平衡（non-LTE）效应，这需要精确的碰撞速率系数以进行可靠的天体物理建模和未来的天文搜索。目标。我们旨在为两种乙亚胺异构体提供与主要冷分子云碰撞伙伴He和para-H2的首个碰撞数据集，以支持non-LTE辐射转移建模。方法。通过对不同能量范围内的混合密耦合（CC）和耦合态（CS）散射截面进行积分，计算了与He碰撞的态到态速率系数。此外，与针对He和para-H2碰撞进行的混合量子经典理论（MQCT）计算进行比较，推导出跃迁特定的缩放因子，并将其应用于预测para-H2的碰撞速率系数。结果。我们提供了E-和Z-乙亚胺与He和para-H2碰撞的首个态到态碰撞数据集，包括涉及低于50 cm-1能级的所有转动跃迁，温度范围为5-100 K。结论。这里报告的数据集为乙亚胺在冷星际环境中的non-LTE建模提供了首个碰撞信息。它们代表了向更可靠的丰度测定迈出的关键一步，并可能促进未来在Sgr B2(N)之外对两种乙亚胺异构体的天文探测。
英文摘要
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-H2, 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-H2 collisions enabled the derivation of transition-specific scaling factors, which were applied to predict collisional rate coefficients for para-H2. Results. We present the first state-to-state collisional datasets for both E- and Z-ethanimine in collision with He and para-H2, 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).
发表机构
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251（雷恩大学，法国国家科学研究中心，雷恩物理研究所）
- Marquette University（马凯特大学）
- Missouri University of Science and Technology（密苏里科技大学）
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