论文标题
断开点：以银河系的方式重新审视恒星“弦”的性质
Disconnecting the Dots: Re-Examining the Nature of Stellar "Strings" in the Milky Way
论文作者
论文摘要
GAIA数据的最新分析导致了新的恒星结构的识别，其中包括新的扩展恒星细丝称为Stellar“ Stellar”，首先提出的是Kounkel and Covey 2019。我们探索了弦的空间，运动和化学组成，以证明这些新发现的结构在物理上是众多的对象，而这些成员是众所周知的对象。在检查字符串构件的3D空间分布时，我们发现围绕声称的弦脊柱的空间分散在最新的Gaia DR3数据发布中并没有改善 - 尽管在视差测量值的信噪比中有明显的收益，这与对真正的FIDE结构的期望背道而驰。使用字符串的径向速度分散（平均$ \rmσ_{v_r} = 16 \; km \; km \; s^{ - 1} $）来估计它们的病毒质量，我们发现所有字符串在重力均不重。鉴于琴弦正在分散的发现，报道的字符串恒星年龄通常比其测量的分散时间大120美元。最后，我们证明了先前的工作表明，恒星弦在化学上比本地田间星是更均匀的，但是证明可以通过从空间，时间和运动学上无关的开放式群中抽取随机的恒星来获得相同的化学同质性特征。我们的结果表明，尽管某些字符串可能由实际的子结构组成，但没有一致的证据表明样品上较大的弦乐连接。这些结果强调了过度解释这些字符串的重要性及其在理解银河系恒星形成历史中的作用时需要谨慎的需求。
Recent analyses of Gaia data have resulted in the identification of new stellar structures, including a new class of extended stellar filaments called stellar "strings", first proposed by Kounkel and Covey 2019. We explore the spatial, kinematic, and chemical composition of strings to demonstrate that these newfound structures are largely inconsistent with being physical objects whose members share a common origin. Examining the 3D spatial distribution of string members, we find that the spatial dispersion around the claimed string spine does not improve in the latest Gaia DR3 data release -- despite tangible gains in the signal-to-noise of the parallax measurements -- counter to expectations of a bona fide structure. Using the radial velocity dispersion of the strings (averaging $\rmσ_{V_r} = 16\;km\;s^{-1}$) to estimate their virial masses, we find that all strings are gravitationally unbound. Given the finding that the strings are dispersing, the reported stellar ages of the strings are typically $120\times$ larger than their measured dispersal times. Finally, we validate prior work that stellar strings are more chemically homogeneous than their local field stars, but show it is possible to obtain the same signatures of chemical homogeneity by drawing random samples of stars from spatially, temporally, and kinematically unrelated open clusters. Our results show that while some strings may be composed of real sub-structures, there is no consistent evidence for larger string-like connections over the sample. These results underline the need for caution in over-interpreting the significance of these strings and their role in understanding the star formation history of the Milky Way.
