RUI: Resolving Astrophysical Water Formation Pathways on Dust Grain Surfaces

RUI：解决尘埃颗粒表面的天体物理水形成路径

• 批准号: 1616992
• 负责人: Gerardo Dominguez
• 金额: $ 30.58万
• 依托单位: California State University San Marcos Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1616992&HistoricalAwards=false
• 关键词: RUI; Resolving; Astrophysical; Water; Formation

Dust grains in cold interstellar gas clouds provide sites for chemical reactions of simple atoms and molecules. Reactions on dust grains can produce molecules such as water, which is one of nature's most important compounds, and is essential to life as we currently know it. This research project will use advanced experimental techniques to study how water forms on cold surfaces similar to those of dust grains in space. Results from the study will help astronomers understand how processes on interstellar dust grains can produce water in space. Understanding these processes could also allow astronomers to understand the origins of Earth's water. The project, conducted at an undergraduate institution with a largely Hispanic student body, will train students in methods of advanced scientific research.The principal investigator will undertake laboratory studies of water formation on cold surfaces to: (1) understand the predominant formation pathways of water on dust grains in cold molecular clouds and protoplanetary disks; and (2) explain the anomalously high 16-oxygen abundance in the Sun relative to the terrestrial planets. Specifically, the studies will gauge the relative importance of two water formation pathways --- H + oxygen and H + ozone --- by depositing H atoms and oxygen or ozone molecules on a cold surface and then analyzing the isotopic composition of the water molecules produced. This will be done using a cavity-ringdown spectrometer calibrated for isotopic analysis, allowing a direct measurement of the branching ratios of the reactions to within 1%. The investigator will conduct this project at an undergraduate institution with a predominantly Hispanic student body. This will allow him to provide training in laboratory astrophysics to students from diverse backgrounds.

寒冷的星际气体云中的尘埃颗粒为简单原子和分子的化学反应提供了场所。 水是自然界中最重要的化合物之一，是生命所必需的物质。该研究项目将利用先进的实验技术，研究水是如何在类似于太空尘埃颗粒的冷表面上形成的。 这项研究的结果将有助于天文学家了解星际尘埃颗粒的过程如何在太空中产生水。 了解这些过程也可以让天文学家了解地球水的起源。 该项目在一所本科院校进行，学生主要是西班牙裔，将培训学生先进的科学研究方法，首席研究员将进行冷表面水形成的实验室研究，以：（1）了解冷分子云和原行星盘中尘埃颗粒上水的主要形成途径;以及（2）解释太阳中相对于类地行星而言异常高的16-氧丰度。 具体来说，这些研究将通过将H原子和氧或臭氧分子沉积在冷表面上，然后分析产生的水分子的同位素组成，来衡量两种水形成途径- H +氧和H +臭氧的相对重要性。 这将使用校准用于同位素分析的腔衰荡光谱仪来完成，允许直接测量反应的分支比，误差在1%以内。 研究者将在一个以西班牙裔学生为主的本科院校进行本项目。 这将使他能够为来自不同背景的学生提供实验室天体物理学方面的培训。