Interstellar Detection of 2-Cyanocyclopentadiene, C$_5$H$_5$CN, a Second Five-Membered Ring Toward TMC-1

Interstellar Detection of the Highly Polar Five-Membered Ring Cyanocyclopentadiene

Much like six-membered rings, five-membered rings are ubiquitous in organic chemistry, frequently serving as the building blocks for larger molecules, including many of biochemical importance. From a combination of laboratory rotational spectroscopy and a sensitive spectral line survey in the radio band toward the starless cloud core TMC-1, we report the astronomical detection of 1-cyano-1,3-cyclopentadiene, $c$-C$_5$H$_5$CN}, a highly polar, cyano derivative of cyclopentadiene, $c$-C$_5$H$_6$. The derived abundance of $c$-C$_5$H$_5$CN} is far greater than predicted from astrochemical models w…

氰基环戊二烯与氦原子的转动非弹性散射

Rotationally inelastic scattering of cyanocyclopentadiene by helium atoms

本文计算了氰基环戊二烯与氦原子的首个势能面，并通过量子散射计算获得转动激发速率系数，发现倾向于Δk_a=0跃迁，为星际丰度估算提供数据。

Aromatics and Cyclic Molecules in Molecular Clouds: A New Dimension of Interstellar Organic Chemistry

Astrochemistry lies at the nexus of astronomy, chemistry, and molecular physics. On the basis of precise laboratory data, a rich collection of more than 200 familiar and exotic molecules have been identified in the interstellar medium, the vast majority by their unique rotational fingerprint. Despite this large body of work, there is scant evidence in the radio band for the basic building blocks of chemistry on earth -- five and six-membered rings -- despite long standing and sustained efforts during the past 50 years. In contrast, a peculiar structural motif, highly unsaturated carbon in a ch…

在 GOTHAM 对 TMC-1 的观测中探测到星际 $E$-1-氰基-1,3-丁二烯

Detection of Interstellar $E$-1-cyano-1,3-butadiene in GOTHAM Observations of TMC-1

本文利用 GOTHAM 巡天数据在 TMC-1 中首次探测到 $E$-1-氰基-1,3-丁二烯，并以该分子为代理约束了 1,3-丁二烯的气相丰度，结合 NAUTILUS 模型发现其丰度增加约两个数量级，进而探讨了自下而上形成芳香族分子的路径。

Detection of Interstellar H$_2$CCCHC$_3$N

The chemical pathways linking the small organic molecules commonly observed in molecular clouds to the large, complex, polycyclic species long-suspected to be carriers of the ubiquitous unidentified infrared emission bands remain unclear. To investigate whether the formation of mono- and poly-cyclic molecules observed in cold cores could form via the bottom-up reaction of ubiquitous carbon-chain species with, e.g. atomic hydrogen, a search is made for possible intermediates in data taken as part of the GOTHAM (GBT Observations of TMC-1 Hunting for Aromatic Molecules) project. Markov-Chain Mont…

在极低光度天体（VeLLO）MC27/L1521F中检测多环芳烃菲（C$_{13}$H$_{10}$）

Detection of the Polycyclic Aromatic Hydrocarbon Phenalene (C$_{13}$H$_{10}$) in the Very Low Luminosity Object (VeLLO) MC27/L1521F

研究在极低光度天体MC27/L1521F中检测多环芳烃菲，通过比较其与单环芳烃苯甲腈在两个源中的丰度，发现菲在该天体中增强四倍，支持PAHs在冷星际介质广泛存在及与恒星形成早期阶段的关系。