Abstract
We have determined the isotopic abundance ratio of 7Li/ 6Li in the interstellar media (ISMs) along lines of sight to HD169454 and HD250290 using the High-Dispersion Spectrograph on the Subaru Telescope. We also observed ζ Oph for comparison with previous data. The observed abundance ratios were 7Li/6Li = 8.1+3.6 -1.8 and 6.3+3.0 -1.7 for HD169454 and HD250290, respectively. These values are in reasonable agreement with those observed previously in the solar neighborhood ISMs within 2σ error bars and are also consistent with our measurement of 7Li/6Li = 7.1+2.9 -1.6 for a cloud along the line of sight to ζ Oph. This is good evidence for homogeneous mixing and instantaneous recycling of the gas component in the Galactic disk. We also discuss several source compositions of 7Li, Galactic cosmic-ray interactions, stellar nucleosynthesis, and big bang nucleosynthesis.
Original language | English |
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Pages (from-to) | 1506-1518 |
Number of pages | 13 |
Journal | Astrophysical Journal |
Volume | 701 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2009 |