关于二甲基硫醚的非生物起源：在星际介质中发现DMS
On the abiotic origin of dimethyl sulfide: discovery of DMS in the Interstellar Medium
AI总结：
本研究首次在星际介质分子云G+0.693-0.027中探测到二甲基硫醚（DMS），揭示了其非生物起源机制，并对其作为系外行星可靠生物标志物的适用性提出质疑。
摘要：
继在彗星67P/Churyumov-Gerasimenko中发现二甲基硫醚（CH$_3$SCH$_3$，DMS）的特征后，我们报告了在星际介质中首次探测到这种有机硫物种，这是在利用Yebes 40$\,$m和IRAM 30$\,$m望远镜对银河系中心分子云G+0.693-0.027进行超深分子谱线巡天探索期间获得的。我们推导出分子柱密度为$N$ = (2.6 $\pm$ 0.3)$\times$10$^{13}$ cm$^{-2}$，相对于H$_2$的丰度分数为$\sim$1.9$\times$10$^{-10}$。这意味着在该云层中，DMS的丰度比其结构异构体CH$_3$CH$_2$SH低约1.6倍，比其O类似物二甲醚（CH$_3$OCH$_3$）低约30倍，这与先前关于各种O/S对的结果高度一致。此外，我们发现G+0.693-0.027中DMS/CH$_3$OH的相对丰度（$\sim$1.7$\times$10$^{-3}$）与彗星中的（$\sim$1.3$\times$10$^{-3}$）存在显著相似性。尽管地球之外DMS的化学机制尚未完全揭示，但这一发现提供了其在星际介质中高效非生物产生的确凿观测证据，从而对在系外行星科学中将DMS作为可靠生物标志物提出了质疑。
英文摘要：
Following the discovery of dimethyl sulfide (CH$_3$SCH$_3$, DMS) signatures in comet 67P/Churyumov-Gerasimenko, we report the first detection of this organosulfur species in the interstellar medium, during the exploration of an ultradeep molecular line survey performed toward the Galactic Center molecular cloud G+0.693-0.027 with the Yebes 40$\,$m and IRAM 30$\,$m telescopes. We derive a molecular column density of $N$ = (2.6 $\pm$ 0.3)$\times$10$^{13}$ cm$^{-2}$, yielding a fractional abundance relative to H$_2$ of $\sim$1.9$\times$10$^{-10}$. This implies that DMS is a factor of $\sim$1.6 times less abundant than its structural isomer CH$_3$CH$_2$SH and $\sim$30 times less abundant than its O-analogue dimethyl ether (CH$_3$OCH$_3$) toward this cloud, in excellent agreement with previous results on various O/S pairs. Furthermore, we find a remarkable resemblance between the relative abundance of DMS/CH$_3$OH in G+0.693-0.027 ($\sim$1.7$\times$10$^{-3}$) and in the comet ($\sim$1.3$\times$10$^{-3}$). Although the chemistry of DMS beyond Earth is yet to be fully disclosed, this discovery provides conclusive observational evidence on its efficient abiotic production in the interstellar medium, casting doubts about using DMS as a reliable biomarker in exoplanet science.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
