论文标题

银河考古发掘(Galileo)I。跨银色巨人的最新人口普查

Galactic ArchaeoLogIcaL ExcavatiOns (GALILEO) I. An updated census of APOGEE N-rich giants across the Milky Way

论文作者

Fernández-Trincado, José G., Beers, Timothy C., Barbuy, Beatriz, Minniti, Dante, Chiappini, Cristina, Garro, Elisa R., Tang, Baitian, Alves-Brito, Alan, Villanova, Sandro, Geisler, Doug, Lane, Richard R., Diaz, Danilo G.

论文摘要

(删节)我们使用Apache Point天文台银河进化实验(Apogee-2)的第二阶段的第17个数据释放,以在银河系(MW)(MW)中提供N富红色巨星的同质普查。我们报告总共有149个新近识别的N型田野巨头朝向我们银河系的凸起,金属贫困盘和光环。它们在氮的丰度比([N/Fe] $ \ gtrsim +0.5 $)上表现出明显的富集,以及[C/Fe]丰度比([C/Fe] $ < +0.15 $)的同时耗尽,并且它们覆盖了多种金属范围($ -1.8 <$ [FE/H] $ 0. $ 0.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.77.7.7.7.7.7.7.7.7.7.7.7.7.7.77.7.77.7.7.7.7.7.77.7.77.77.77.7.7.77.1.7.7.7.77.1.7.77.1.7.77.77.77.77.7。 Apogee调查中的最终样本具有富含球形群集的候选红色巨星(类似GC)的丰度模式,包括总计$ \ sim $ 412独特的对象。据推测,这些强烈的N增强恒星已根据它们与这些系统的化学相似性从GC中剥离。即使我们还没有找到有关二进制伴侣或脉动变异性的签名的有力证据,但我们不能排除这些对象中的某些对象过去和/或当前是可变系统的一部分的可能性。特别是,我们在银河系中识别出田间恒星中的这样的恒星提供了有力的证据,表明产生异常[N/Fe]丰度比的核合成过程(ES)发生在多种金属范围内。这可能提供证据,以表明祖先星对GC的独特性和/或与可能在巨大的矮星系中潮汐切碎的簇相关的化学异常存在,例如“ Kraken/Koala”,例如Kraken/Koala,\ textit {gaia} -celedit {gaia} -Cenceladus-sausage,在其他或其他情况下,在其其他过程中。动态分析表明,新近鉴定的富含N的恒星在整个MW中表现出广泛的动力学特征,...

(ABRIDGED) We use the 17th data release of the second phase of the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) to provide a homogenous census of N-rich red giant stars across the Milky Way (MW). We report a total of 149 newly identified N-rich field giants toward the bulge, metal-poor disk, and halo of our Galaxy. They exhibit significant enrichment in their nitrogen abundance ratios ([N/Fe] $\gtrsim+0.5$), along with simultaneous depletions in their [C/Fe] abundance ratios ([C/Fe] $< +0.15$), and they cover a wide range of metallicities ($-1.8 < $ [Fe/H] $ <-0.7$). The final sample of candidate N-rich red giant stars with globular-cluster-like (GC-like) abundance patterns from the APOGEE survey includes a grand total of $\sim$ 412 unique objects. These strongly N-enhanced stars are speculated to have been stripped from GCs based on their chemical similarities with these systems. Even though we have not found any strong evidence for binary companions or signatures of pulsating variability yet, we cannot rule out the possibility that some of these objects were members of binary systems in the past and/or are currently part of a variable system. In particular, the fact that we identify such stars among the field stars in our Galaxy provides strong evidence that the nucleosynthetic process(es) producing the anomalous [N/Fe] abundance ratios occurs over a wide range of metallicities. This may provide evidence either for or against the uniqueness of the progenitor stars to GCs and/or the existence of chemical anomalies associated with likely tidally shredded clusters in massive dwarf galaxies such as "Kraken/Koala," \textit{Gaia}-Enceladus-Sausage, among others, before or during their accretion by the MW. A dynamical analysis reveals that the newly identified N-rich stars exhibit a wide range of dynamical characteristics throughout the MW, ...

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