标题： B超巨星风中广泛聚集的特征 显示英文标题

标题： Signature of wide-spread clumping in B supergiant winds

摘要： 我们旨在建立OB星风中团块效应的额外观测特征。测试团块对关键风形成光谱线的作用，以指导团块风模型的发展，从而提高大质量恒星质量损失确定的可靠性。使用经验线合成模型分析B0至B5超巨星的SiIV 1400共振线双线。重点是解码来自SiIV双线红、蓝组分径向光学深度（tau_(rad)(w)）比值的风团块信息。特别是利用了对于具有相对较低风终端速度的目标，两个双线组分相互解耦并独立形成这一事实。线合成分析表明，蓝组分与红组分的tau_(rad)(w)平均比值很少接近约2的典型值（从原子常数预期），而是分布在约1到2之间的范围内。这些结果被解释为光球部分被流出气体中的光学厚结构遮挡。本研究确立的光谱特征证明了B型超巨星风中团块的广泛存在。未饱和双线轮廓中的附加信息提供了一种量化风孔隙度的方法。 显示英文摘要

摘要： We seek to establish additional observational signatures of the effects of clumping in OB star winds. The action of clumping on strategic wind-formed spectral lines is tested to steer the development of models for clumped winds and thus improve the reliability of mass-loss determinations for massive stars.The SiIV 1400 resonance line doublets of B0 to B5 supergiants are analysed using empirical line-synthesis models. The focus is on decoding information on wind clumping from measurements of ratios of the radial optical depths (tau_(rad)(w)) of the red and blue components of the SiIV doublet. We exploit in particular the fact that the two doublet components are decoupled and formed independently for targets with relatively low wind terminal velocities. Line-synthesis analyses reveal that the mean ratio of tau_(rad)(w) of the blue to red SiIV components are rarely close to the canonical value of ~ 2 (expected from atomic constants), and spread instead over a range of values between ~1 and 2. These results are interpreted in terms of a photosphere that is partially obscured by optically thick structures in the outflowing gas.The spectroscopic signatures established in this study demonstrate the wide-spread existence of wind clumping in B supergiants. The additional information in unsaturated doublet profiles provides a means to quantify the porosity of the winds.