标题： 宇宙学中首次测量本地星际介质中$^3$氦丰度的启示 显示英文标题

标题： Cosmological Implications of the First Measurement of the Local ISM Abundance of $^3$He

摘要： Deuterium plays a crucial role in testing big-bang nucleosynthesis. Its chemical evolution, while simple (it is burned to $^3$He), is intertwined with the more complicated evolution of $^3$He. Gloeckler & Geiss' new measurement of the $^3$He abundance and the HST measurement of D, both in the local ISM today, can be compared to the pre-solar nebula abundances of D and $^3$He. Within the uncertainties, the sum of D + $^3$He relative to hydrogen is unchanged. 这为Yang等（1984）最初提出的D +$^3$He的宇宙学应用提供了一些验证，并进一步表明，在过去45亿年里，最多只有适度的恒星产生了$^3$He，这与恒星建模相矛盾，或者只是适度的恒星破坏了$^3$He，这与某些“太阳勺”相矛盾。 虽然早期银河系的D +$^3$He演化不能被直接限制，但预计它将由大量恒星主导，这些恒星会耗尽它们的$^3$He并产生金属。 基于银河系金属丰度以及过去45亿年氘（D）和氦-3 ($^3$He) 的恒定性，我们得出了一个更基于观测的宇宙重子密度下限；虽然与杨等人（1984年）基于氘（D）和氦-4 ($^3$He) 得出的原始界限相差不大，但它缓解了大爆炸核合成理论预言的氦-4 ($^4$He) 丰度与氘（D）和氦-3 ($^3$He) 丰度之间的部分宇宙学张力。 显示英文摘要

摘要： Deuterium plays a crucial role in testing big-bang nucleosynthesis. Its chemical evolution, while simple (it is burned to $^3$He), is intertwined with the more complicated evolution of $^3$He. Gloeckler \& Geiss' new measurement of the $^3$He abundance and the HST measurement of D, both in the local ISM today, can be compared to the pre-solar nebula abundances of D and $^3$He. Within the uncertainties, the sum of D + $^3$He relative to hydrogen is unchanged. This provides some validation of the cosmological utility of D + $^3$He, first suggested by Yang et al (1984), and further, indicates that over the past 4.5 Gyr there has been at most modest stellar production of $^3$He, in contradiction with stellar modeling, or modest stellar destruction of $^3$He, in contradiction with some ``solar spoons.'' While the earlier Galactic evolution of D + $^3$He cannot be constrained directly, it is expected to be dominated by massive stars, which deplete their $^3$He and produce metals. Based on the Galactic metallicity and the constancy of D + $^3$He over the past 4.5 Gyr, we derive a more empirically based lower bound to the cosmological baryon density; while not dramatically different from the original bound of Yang et al (1984) based on D + $^3$He, it alleviates some of the cosmic tension between the big-bang $^4$He abundance and those of D and $^3$He.