论文标题
P-PICH星星中的重元素丰度：S过程的新站点？
Heavy element abundances in P-rich stars: A new site for the s-process?
论文作者
论文摘要
最近发现的富含磷的恒星对恒星进化和核合成理论构成了挑战，因为现有模型都无法解释其极其特殊的化学丰度模式。除了大磷增强外，此类恒星还显示出其他光（O，MG，SI，AL）和重（例如CE）元素的增强。我们已经获得了两个光学亮磷的恒星（包括新的Pich恒星）的高分辨率光谱，为此，我们已经阻止了较大数量的元素丰度（从C到PB）。 We confirm the unusual light-element abundance pattern with very large enhancements of Mg, Si, Al, and P, and possibly some Cu enhancement, but the spectra of the new P-rich star is the only one to reveal some C(+N) enhancement.When compared to other appropriate metal-poor and neutron-capture enhanced stars, the two P-rich stars show heavy-element overabundances similar to low neutron density s-process核合成，具有较高的第一（SR，Y，ZR）和第二峰（BA，LA，CE，ND）元件增强（甚至是一颗恒星的PB增强）和负[RB/SR]比率。但是，该S过程与渐近巨型分支（AGB）恒星中发生的S过程不同。显着的区别包括比其AGB对应物更大的[BA/LA]和更低的欧盟和Pb。我们的观察结果应指导出色的核合成理论家和观察者识别Pich富含Pich的祖先，这代表了S过程中S过程的核合成部位，对我们的星系的化学演化具有重要意义。
The recently discovered phosphorus-rich stars pose a challenge to stellar evolution and nucleosynthesis theory, as none of the existing models can explain their extremely peculiar chemical abundances pattern. Apart from the large phosphorus enhancement, such stars also show enhancement in other light (O, Mg, Si, Al) and heavy (e.g., Ce) elements. We have obtained high-resolution optical spectra of two optically bright phosphorus-rich stars (including a new P-rich star), for which we have deter-mined a larger number of elemental abundances (from C to Pb). We confirm the unusual light-element abundance pattern with very large enhancements of Mg, Si, Al, and P, and possibly some Cu enhancement, but the spectra of the new P-rich star is the only one to reveal some C(+N) enhancement.When compared to other appropriate metal-poor and neutron-capture enhanced stars, the two P-rich stars show heavy-element overabundances similar to low neutron density s-process nucleosynthesis,with high first- (Sr, Y, Zr) and second-peak (Ba, La, Ce, Nd) element enhancements (even some Pb enhancement in one star) and a negative [Rb/Sr] ratio. However, this s-process is distinct from the one occurring in asymptotic giant branch (AGB) stars. The notable distinctions encompass larger[Ba/La] and lower Eu and Pb than their AGB counterparts. Our observations should guide stellar nucleosynthesis theoreticians and observers to identify the P-rich star progenitor, which represents anew site for s-process nucleosynthesis, with important implications for the chemical evolution of our Galaxy.
