Oxygen Gas-Phase Abundance Revisited
Oxygen Gas-Phase Abundance Revisited
复制标题
重新审视氧气气相丰度
DOI：
10.1086/375530
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
H. Moos
中科院分区：
文献类型：
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作者：
M. André;M. André;C. Oliveira;J. Howk;R. Ferlet;J. Désert;G. Hébrard;S. Lacour;A. D. Étangs;A. Vidal;H. Moos
我们提出了新的测量星际气相氧丰度沿着视线朝向19个早期型银河系恒星在平均距离为2.6千秒差距。利用哈勃空间望远镜/空间望远镜成像光谱仪（HST/STIS）观测到的1355 μ s弱系间跃迁，推导出O I柱密度。利用HST/STIS对Lyα的观测和远紫外光谱探测器（FUSE）对分子氢的观测，得到了总氢柱密度[N（H）+ 2N（H2）]。这些视线的分子氢含量范围为f（H2）= 2N（H2）/[N（H）+2N（H2）] = 0.03至0.47。6.3 × 1021 cm-2 mag-1的平均EB-Htot/EB-V平均值与15%的标准差与以前的调查一致。沿着这些视线的平均氧丰度沿着是106（O/H）气体= 408 ± 13（平均值为1 σ），这些视线探测了遥远星际介质中的大范围银河系环境。我们没有看到任何证据表明，随着分子氢分数的增加，气相氧丰度降低，（O/H）气体的相对恒定性表明，含有氧的尘埃成分不容易被破坏。我们估计，如果60%的尘埃颗粒对冲击的破坏有弹性，那么遥远的星际总氧丰度可以与最近测量的106（O/H）气体的值= 517 ± 58（1 σ）相一致。我们注意到，在500秒差距内或从附近的B星星调查得出的星际气体的氧丰度较小，与当地的元素赤字是一致的。
We present new measurements of the interstellar gas-phase oxygen abundance along the sight lines toward 19 early-type Galactic stars at an average distance of 2.6 kpc. We derive O I column densities from Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations of the weak 1355 Å intersystem transition. We derive total hydrogen column densities [N(H ) + 2N(H2)] using HST/STIS observations of Lyα and Far Ultraviolet Spectroscopic Explorer (FUSE) observations of molecular hydrogen. The molecular hydrogen content of these sight lines ranges from f(H2) = 2N(H2)/[N(H ) + 2N(H2)] = 0.03 to 0.47. The average ⟨Htot/EB-V⟩ of 6.3 × 1021 cm-2 mag-1 with a standard deviation of 15% is consistent with previous surveys. The mean oxygen abundance along these sight lines, which probe a wide range of Galactic environments in the distant interstellar medium, is 106 (O/H)gas= 408 ± 13 (1 σ in the mean). We see no evidence for decreasing gas-phase oxygen abundance with increasing molecular hydrogen fraction, and the relative constancy of (O/H)gas suggests that the component of dust containing the oxygen is not readily destroyed. We estimate that, if 60% of the dust grains are resilient against destruction by shocks, the distant interstellar total oxygen abundance can be reconciliated with the solar value derived from the most recent measurements of 106 (O/H)gas☉= 517 ± 58 (1 σ). We note that the smaller oxygen abundances derived for the interstellar gas within 500 pc or from nearby B star surveys are consistent with a local elemental deficit.