论文标题
彗星67p/churyumov-gerasimenko的昏迷中的分子依赖性氧同位素比
Molecule dependent oxygen isotopic ratios in the coma of comet 67P/Churyumov-Gerasimenko
论文作者
论文摘要
地球上三个稳定的氧同位素16o，17o和18o的比率，据我们在太阳系中所知，最多只有几个百分之几的差异，而陨石中有一些异常值。然而，在星际培养基中，某些特定分子中有一些高分数的同位素比。这项工作的目的是研究在67p/churyumov-gerasimenko昏迷中发现的不同挥发性分子中的氧同位素比，并将它们与星际云的发现进行比较，以评估共同点和差异。为了实现这一目标，我们在Rosetta围绕彗星的任务中分析了Rosina乐器的数据。可以确定16o/18o的比率，用于O2，甲醇，甲醛，羰基硫化物和一氧化硫/二氧化硫。对于O2，也可以使用16o/17o的比率。某些比率在繁重的同位素中非常富含，尤其是对于硫轴承分子和甲醛，而对于甲醇，该比与太阳系中的比率兼容。 O2之间落在两者之间，但其氧同位素比显然与水有所不同，水很可能排除了水的起源，无论是通过辐射分解，升华期间的散布还是从击中核心击中原子核的埃利 - 里德的过程中，如文献中所假定的。
The ratios of the three stable oxygen isotopes 16O, 17O and 18O on Earth and, as far as we know in the solar system, show variations on the order of a few percent at most, with a few outliers in meteorites. However, in the interstellar medium there are some highly fractionated oxygen isotopic ratios in some specific molecules. The goal of this work is to investigate the oxygen isotopic ratios in different volatile molecules found in the coma of comet 67P/Churyumov-Gerasimenko and compare them with findings from interstellar clouds in order to assess commonalities and differences. To accomplish this goal, we analyzed data from the ROSINA instrument on Rosetta during its mission around the comet. 16O/18O ratios could be determined for O2, methanol, formaldehyde, carbonyl sulfide and sulfur monoxide/dioxide. For O2 the 16O/17O ratio is also available. Some ratios are strongly enriched in the heavy isotopes, especially for sulfur bearing molecules and formaldehyde, whereas for methanol the ratios are compatible with the ones in the solar system. O2 falls in-between, but its oxygen isotopic ratios clearly differ from water, which likely rules out an origin of O2 from water, be it by radiolysis, dismutation during sublimation or the Eley-Rideal process from water ions hitting the nucleus as postulated in the literature.
