AI 中文总结
本研究利用APOGEE DR17数据约束富氮场星的形成位点，发现其双星比例与化学正常场星无显著差异，不支持双星质量转移为主要形成通道，证实其多为球状星团逃逸体。
AI 中文摘要
近期詹姆斯·韦布空间望远镜（JWST）的观测发现，部分星系具有异常高的N/O比值，表明氮增丰可能在早期宇宙的强恒星形成环境中普遍存在。在银河系中，银场的富氮（N-rich）恒星长期以来被用作探测早期银河系形成及球状星团（GC）增丰的探针。然而，对这些恒星中双星的识别，提出了双星质量转移可能对其起源有贡献的可能性。本研究利用APOGEE DR17的多历元视向速度及元素丰度来限制这些恒星的形成位点。在266颗富氮场星中，33颗表现出ΔRV > 1 km/s的视向速度变化，其中在46颗采样充分的恒星子集中，通过F₂统计识别出10颗可靠的分光双星。由此得到的密近双星比例为（21.7±6.1%），与化学正常场星的比例（18.1±0.6%）在统计上无显著差异，未发现渐近巨星分支（AGB）双星污染所预期的过量证据。[N/Fe]与[Ce/Fe]无相关性，且不存在[C/Fe]增丰，进一步支持了这一结论。关键的是，我们检测到双星比例与[Al/Fe]呈反相关，强铝增丰恒星（[Al/Fe] ≳ 0.5）的双星比例降低至<10%。这一趋势是高密度环境的动力学特征，与球状星团核心中通过三体相互作用高效瓦解双星的情况一致。我们的结果不支持双星质量转移是富氮场星的主要形成通道；这些恒星主要是保留了其致密诞生位点动力学记忆的球状星团逃逸体。
英文摘要
Recent JWST observations have revealed galaxies with unusually high N/O ratios, suggesting that nitrogen enrichment may be common in intense star-forming environments in the early Universe. In the Milky Way, nitrogen-rich(N-rich) stars in the Galactic field have long served as probes of early Galaxy formation and globular cluster enrichment. However, the identification of binaries among these stars raises the possibility that binary mass transfer could contribute to their origin. In this work, we utilize multi-epoch radial velocities and element abundances from APOGEE DR17 to constrain their formation sites. Among 266 N-rich field stars, 33 exhibit radial velocity variations of $Δ{\rm RV} > 1\,{\rm km/s}$, including 10 robust spectroscopic binaries identified using the $F_2$ statistic within a well-sampled subset of 46 stars. The resulting close-binary fraction ($21.7\pm6.1\%$) is statistically indistinguishable from that of chemically normal field stars ($18.1\pm0.6\%$), showing no evidence of the excess expected from AGB binary pollution. This is further supported by the absence of correlation between [N/Fe] and [Ce/Fe] and the lack of [C/Fe] enhancement. Crucially, we detect an anti-correlation between binary fraction and [Al/Fe], with strongly Al-enhanced stars ($[\mathrm{Al/Fe}] \gtrsim 0.5$) exhibiting a reduced binary fraction ($< 10\%$). This trend serves as a dynamical fingerprint of high-density environments, consistent with the efficient disruption of binaries via three-body interactions in GC cores. Our results do not support binary mass transfer as the dominant formation channel for N-rich field stars; they are predominantly GC escapees that retain the dynamical memory of their dense birth sites.
