标题： 太阳邻域B型恒星的磷丰度 显示英文标题

标题： Phosphorus Abundances of B-Type Stars in the Solar Neighborhood

摘要： 磷的丰度约为80颗显然明亮的、具有清晰谱线的早型至晚型B型恒星，在上主序星上的测定是通过应用非局部热平衡分析方法对6043.084 A的P II谱线进行分析，目的是为了获得银河系气体中磷的丰度信息（这些年轻的恒星就是从其中形成的），并与参考太阳丰度（A_sun = 5.45）进行比较。 这些样本恒星根据其磷的丰度被分成两个明显的组别：(1) 化学异常的晚型B型恒星，属于HgMn族，显示出显著的磷过量（超太阳丰度约0.5--1.5 dex），其程度随着有效温度T_eff逐渐增加。 (2) 相反，正常B型恒星的磷丰度相对均匀，尽管在LTE和非LTE情况下观察到明显差异。 虽然它们的LTE丰度接近太阳，但观察到与T_eff有关的轻微渐变趋势。 然而，在应用了负的非LTE修正（约0.1-0.5 dex）后，这种T_eff依赖性成功被消除，但得到的非LTE丰度（其平均值约为5.20）相对于太阳明显缺乏，约低0.2--0.3 dex。 这一系统性差异的原因（与银河系化学演化相矛盾）尚待进一步研究。 显示英文摘要

摘要： Phosphorus abundances of ~80 apparently bright sharp-lined early-to-late B-type stars on the upper main sequence are determined by applying the non-LTE analysis to the P II line at 6043.084 A, with an aim of getting information on the P abundance of the galactic gas (from which these young stars were formed) in comparison with the reference solar abundance (A_sun = 5.45). These sample stars turned out to be divided into two distinct groups with respect to their P abundances: (1) chemically peculiar late B-type stars of HgMn group show considerable overabundances of P (supersolar by ~0.5--1.5 dex), the extent of which progressively increases with T_eff. (2) In contrast, the P abundances of normal B-type stars are comparatively homogeneous, though a notable difference is observed between the LTE and non-LTE cases. Although their LTE abundances are near-solar, a slight gradual trend with T_eff is observed. However, after applying the negative non-LTE corrections (amounting ~0.1-0.5 dex), this T_eff-dependence is successfully removed, but the resulting non-LTE abundances (their mean is ~5.20) are appreciably underabundant relative to the Sun by ~0.2--0.3 dex. The cause of this systematic discrepancy (contradicting the galactic chemical evolution) is yet to be investigated.