Department of Chemistry, Union College, Schenectady, New York 12308, United States.
Department of Astronomy, University of Virginia, Charlottesville, Virginia 22904, United States.
J Phys Chem A. 2022 May 5;126(17):2716-2728. doi: 10.1021/acs.jpca.2c01435. Epub 2022 Apr 20.
We have conducted an extensive search for nitrogen-, oxygen-, and sulfur-bearing heterocycles toward Taurus Molecular Cloud 1 (TMC-1) using the deep, broadband centimeter-wavelength spectral line survey of the region from the GOTHAM large project on the Green Bank Telescope. Despite their ubiquity in terrestrial chemistry, and the confirmed presence of a number of cyclic and polycyclic hydrocarbon species in the source, we find no evidence for the presence of any heterocyclic species. Here, we report the derived upper limits on the column densities of these molecules obtained by Markov Chain Monte Carlo (MCMC) analysis and compare this approach to traditional single-line upper limit measurements. We further hypothesize why these molecules are absent in our data, how they might form in interstellar space, and the nature of observations that would be needed to secure their detection.
我们利用绿岸望远镜上的 GOTHAM 大型项目对金牛座分子云 1（TMC-1）进行了深度、宽带厘米波长谱线调查，广泛搜索了含氮、氧和硫的杂环化合物。尽管它们在地球化学中无处不在，并且该源中已经确认存在一些环状和多环烃类物质，但我们没有发现任何杂环化合物存在的证据。在这里，我们通过马尔可夫链蒙特卡罗（MCMC）分析报告了这些分子的柱密度的导出上限，并将这种方法与传统的单谱线上限测量进行了比较。我们进一步假设了这些分子在我们的数据中缺失的原因，它们在星际空间中可能形成的方式，以及需要进行什么样的观测才能确保它们的探测。
