Floss Christine, Stadermann Frank J, Bradley John, Dai Zu Rong, Bajt Sasa, Graham Giles
Laboratory for Space Sciences, Washington University, St. Louis, MO 63130, USA.
Science. 2004 Feb 27;303(5662):1355-8. doi: 10.1126/science.1093283.
Because hydrogen and nitrogen isotopic anomalies in interplanetary dust particles have been associated with carbonaceous material, the lack of similar anomalies in carbon has been a major conundrum. We report here the presence of a 13C depletion associated with a 15N enrichment in an anhydrous interplanetary dust particle. Our observations suggest that the anomalies are carried by heteroatomic organic compounds. Theoretical models indicate that low-temperature formation of organic compounds in cold interstellar molecular clouds can produce carbon and nitrogen fractionations, but it remains to be seen whether the specific effects observed here can be reproduced.
由于行星际尘埃粒子中的氢和氮同位素异常与含碳物质有关，碳中缺乏类似异常一直是一个主要难题。我们在此报告在一个无水行星际尘埃粒子中存在与15N富集相关的13C亏损。我们的观察结果表明，这些异常是由杂原子有机化合物携带的。理论模型表明，在寒冷的星际分子云中有机化合物的低温形成可以产生碳和氮的分馏，但这里观察到的具体效应是否能够重现仍有待观察。
