论文标题
金属差的本地恒星形成星系中的元素丰度受弱光谱线约束
Element abundances in metal poor local star-forming galaxies constrained by the weak spectral lines
论文作者
论文摘要
我们从不同的调查中收集了一些从当地宇宙中的星形星系观察到的一些重要的光谱数据。为了限制模型，选择了来自不同元素的线数的对象。特别是，我们研究了相对较弱的线，例如[OIII] 4363，HEII4686，HEI4471和HEI5876。我们通过恒星和冲击的光电离效果详细建模了光谱。我们发现，相对于大多数元素的H的丰度低于太阳能，但不如直接强线和TE方法评估的元素低。通过[SII] 6717，6731和[SIII] 6312线出现的硫不会耗尽，揭示了ISM的强烈贡献。我们已经添加了样品中含有CIV/HB和CIII和Hb线比的局部低金属矮星系的光谱光谱，以便以相对精度的C/H相对丰度确定。结果表明，在某些物体中，他/H比太阳能低，并表明云的几何厚度限制了HEII/HB线的比率。我们通过将恒星形成区域的风与ISM云混合来解释低HE/H。
We have collected from different surveys some significant spectroscopic data observed from star-forming galaxies in the local Universe. The objects showing a relatively rich spectrum in number of lines from different elements were selected in order to constrain the models. In particular, we looked at the relatively weak lines such as [OIII]4363, HeII4686, HeI4471 and HeI5876. We have modelled in detail the spectra by the coupled effect of photoionization from the stars and shocks. We have found that the abundances relative to H of most of the elements are lower than solar but not as low as those evaluated by the direct strong line and the Te methods. Sulfur which appears through the [SII]6717, 6731 and [SIII]6312 lines is not depleted, revealing a strong contribution from the ISM. We have added to the sample the optical-UV spectra of local low-metallicity dwarf galaxies containing the CIV/Hb and CIII]/Hb line ratios in order to determine with relative precision the C/H relative abundance. The results show He/H lower than solar in some objects and suggest that the geometrical thickness of the clouds constrains the HeII/Hb line ratios. We explain the low He/H by mixing of the wind from the star-forming region with ISM clouds.
