论文标题
部分可观测时空混沌系统的无模型预测
Evidence of Deep Mixing in IRS 7, a Cool Massive Supergiant Member of the Galactic Nuclear Star Cluster
论文作者
论文摘要
银河系的中心包含跨越年龄和金属性范围的恒星种群，近期的恒星构成产生了年轻和庞大的恒星。以$^{19} $ f，$^{12} $ c，$^{13} $ c，$^{13} $ c，$^{14} $ n，$^{14} $ n，$^{16} $，$^{16} $，$^{17} $，$^{17} $ O，和Fe Fe fe a s sprive an s sprive an和a l te上的模型25m $ _ {\ odot} $模型氛围，其化学反应是针对派生的光电丰度量身定制的。 We find IRS 7 to be depleted heavily in both $^{12}$C (~-0.8 dex) and $^{16}$O (~-0.4 dex), while exhibiting an extremely enhanced $^{14}$N abundance (~+1.1 dex), which are isotopic signatures of the deep mixing of CNO-cycled material to the stellar surface. $^{19} $ f丰度也大大耗尽了〜1个DEX相对于核星簇的基线氟，提供了证据，证明氟和碳一起限制了这个非常发光的超级恒定的深层混合的性质。也得出了少数同位素$^{13} $ c和$^{17} $ O的丰度，其比率为$^{12} $ c/$ c/$^{13} $ c〜5.3和$^{16} $ o/$ o/$^{17} $ O〜525。将IRS 7的衍生丰度与NSC中巨大恒星的先前丰度结果结合在一起，与大型恒星的旋转和非旋转模型进行了比较，发现IRS 7的丰度总体上遵循了恒星模型所预测的行为。 IRS 7中枯竭的氟丰度首次说明了使用$^{19} $ f丰度作为发光红色巨人的混合探针的潜力。
The center of the Milky Way contains stellar populations spanning a range in age and metallicity, with a recent star formation burst producing young and massive stars. Chemical abundances in the most luminous stellar member of the Nuclear Star Cluster (NSC), IRS 7, are presented for $^{19}$F, $^{12}$C, $^{13}$C, $^{14}$N, $^{16}$O, $^{17}$O, and Fe from an LTE analysis based on spherical modeling and radiative transfer with a 25M$_{\odot}$ model atmosphere, whose chemistry was tailored to the derived photospheric abundances. We find IRS 7 to be depleted heavily in both $^{12}$C (~-0.8 dex) and $^{16}$O (~-0.4 dex), while exhibiting an extremely enhanced $^{14}$N abundance (~+1.1 dex), which are isotopic signatures of the deep mixing of CNO-cycled material to the stellar surface. The $^{19}$F abundance is also heavily depleted by ~1 dex relative to the baseline fluorine of the Nuclear Star Cluster, providing evidence that fluorine along with carbon constrain the nature of the deep mixing in this very luminous supergiant. The abundances of the minor isotopes $^{13}$C and $^{17}$O are also derived, with ratios of $^{12}$C/$^{13}$C~5.3 and $^{16}$O/$^{17}$O~525. The derived abundances for IRS 7, in conjunction with previous abundance results for massive stars in the NSC, are compared with rotating and non-rotating models of massive stars and it is found that the IRS 7 abundances overall follow the behavior predicted by stellar models. The depleted fluorine abundance in IRS 7 illustrates, for the first time, the potential of using the $^{19}$F abundance as a mixing probe in luminous red giants.
