在多硫和分子八硫库存中缺少星际硫的冠冕
Ashanie Herath1,2, Mason McAnally1,2, Andrew M Turner1,2
1Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI, USA.
Nature communications
|July 2, 2025
概括
实验室实验显示,宇宙射线在星际冰上将硫化 (H2S) 转化为复杂的硫分子. 这解决了冷分子云中长期存在的硫耗尽问题.
科学领域:
- 天体化学是天体化学.
- 宇宙冰化学 宇宙冰化学
- 天体生物学 天体生物学
背景情况:
- 硫耗尽问题,即冷分子云中预测和观察到的硫丰度之间的差异,几十年来一直困扰着科学家.
- 了解硫在星际环境中的化学进化对于天体生物学和行星科学至关重要.
研究的目的:
- 在寒冷的星际环境中,研究硫合并到复杂分子中的化学途径.
- 为分子云中观测到的硫耗尽提供基于实验室的解释.
主要方法:
- 在寒冷条件下 (5K) 进行星际冰化学实验室模拟.
- 用银河系宇宙射线处理硫化 (H2S) 冰.
- 对反应产物的分析,包括硫 (H2Sn) 和八硫 (S8).
主要成果:
- 硫化 (H2S) 在被冰覆盖的星际颗粒上转化为高分子量硫 (H2Sn,n=2-11) 和八硫 (S8).
- 这个过程有效地将气态H2S隔离到固态,复杂的硫分子中,解决了硫耗尽问题.
- 八度硫 (S8) 的形成与最近在小行星瑞古发现的元素硫相一致,将星际硫与太阳系天体联系起来.
结论:
- 银河系宇宙射线对星际颗粒上的H2S进行处理,为冷分子云中缺少的硫提供了一个合理的机制.
- 由此产生的复杂的硫分子,如八硫,可以纳入形成的行星系统中,可能将它们种植在必不可少的元素中.
- 这项研究确立了星际硫化学与它在太阳系中的存在之间的直接联系,比如金牛座分子云和小行星Ryugu.
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