Globular clusters (GCs), as old as our Galaxy, constantly lose their members to the field as they cross through the Milky Way (MW). These GC escaped stars (or escapees) are suggested to contribute significantly to the MW halo. If a star has left the host GC a long time ago, chemical finger prints, e.g., N enrichment, may reveal its origin. In this work, we aim to establish dynamical connections between N-rich field stars recently identified by LAMOST and the existing MW GCs. By constructing the full action distribution, and combining with metallicity, we found 29 potential GC progenitors for 15 N-rich field stars. Particularly, some of them may be related to MW accretion events. On the other hand, if a star recently left its host GC via tidal evaporation, it still maintain the kinematic properties of the cluster. Here we identify extra-tidal candidates based on their spatial locations, proper motions (PMs), and their position on color-magnitude-diagrams (CMDs). We successfully identified more than 1600 extra-tidal candidates in the vicinity of six Gaia-Enceladus (GE)-related GCs (i.e., NGC 1851, NGC 1904, NGC 6205, NGC 6341, NGC 6779, NGC 7089). The density map of the extra-tidal candidates is confirmed to be an efficient way to find extra-tidal structures. The possible two density peaks at opposite directions of the inner boundary is a good indicator for long stellar stream. Among 95 extra-tidal candidates with spectroscopic radial velocities and metallicity, 54 of them are confirmed to be GC escaped stars, as they share similar properties as host GCs. These extra-tidal candidates are ideal targets for follow-up spectroscopic observation, as it greatly improves the scientific outcome. Once statistically significant number of spectroscopic radial velocities and metallicities are available, the GC dynamical evolution (e.g., mass loss, rotation) can be carefully investigated.
Globular clusters of the Gaia Enceladus/Sausage -- I. Orbital and dynamical evolution on cosmological timescales
Main Astronomical Observatory, National Academy of Sciences of Ukraine（乌克兰国家科学院主天文台）；Nicolaus Copernicus Astronomical Centre Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天文学中心）；Fesenkov Astrophysical Institute（费森科夫天体物理研究所）
On the connection between nitrogen-enhanced field stars and the Galactic globular clusters
Institute of Astronomy, University of Cambridge（剑桥大学天文研究所）；School of Mathematics and Physics, The University of Queensland（昆士兰大学数理学院）；Center for Computational Astrophysics, Flatiron Institute（平顿研究所计算天体物理学中心）；Department of Astronomy and Astrophysics, The University of Chicago（芝加哥大学天文学与天体物理学系）
On the Chemical and Kinematic Consistency Between N-rich Metal-poor Field Stars and Enriched Populations in Globular Clusters
有趣的化学奇特场星可能反映了它们的恒星演化历史，以及它们在与现在发现的地方不同的环境中的可能起源，这是银河系考古学中最重要的研究领域之一。为了进一步探索这一点，我们已经使用了CN-CH波段约4000 A，以确定富N金属贫场星在LAMOST DR 3。在这里，我们将我们的富N贫金属场星样本扩展到LAMOST DR 5中的~100颗恒星，其中53颗是在这项工作中新发现的。我们研究了我们的样品和APOGEE DR 14之间的共同恒星的轻元素。虽然Mg、Al和Si的丰度通常与富N贫金属场星来自球状星团中富集的星族的假设一致，但对于C、N和O的丰度仍然没有定论。在整合了我们的富N场星和正常贫金属场星的对照样本的轨道之后，我们发现富N场星与对照样本相比具有不同的轨道参数分布，具体地，远心距离，最大垂直振幅（Zmax），轨道能量和z方向角动量（Lz）。富N场星的轨道参数表明它们大多数是内晕星。富N场星的运动学支持它们可能的GC起源。我们真正的富N场星样本的空间和速度分布是重要的观测证据，以限制模拟这些有趣的物体的起源。
A Tale of Two Origins: In-Situ versus Accreted Nitrogen-Rich Field Stars in the MW
School of Physics and Astronomy, Sun Yat-sen University（中山大学物理学院）；CSST Science Center for the Guangdong-Hong Kong-Macau Greater Bay Area（粤港澳大湾区嫦娥科学中心）；Universidad Católica del Norte（北天主教学会大学）；Department of Astronomy, AlbaNova University Center, Stockholm University（斯德哥尔摩大学阿尔巴诺瓦大学中心天文学系）；Instituto de Astrofísica de Canarias（加那利天体物理学研究所）；Departamento de Astrofísica, Universidad de La Laguna（拉古纳大学天体物理学系）；CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台光学天文重点实验室）；School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）
APOGEE chemical abundances of stars in the MW satellites Fornax, Sextans, Draco and Carina
Sun Yat-sen University（中山大学）；CSST Science Center for the Guangdong-Hong Kong-Macau Greater Bay Area（中国空间站科学中心粤港澳大湾区分中心）；Universidad Católica del Norte（北天主教大学）；Nanjing University（南京大学）
A Census of Pulsars in Possible Association with Galactic Open Clusters
School of Physics and Technology, Wuhan University（武汉大学物理科学与技术学院）；Department of Physics, Faculty of Arts and Sciences, Beijing Normal University（北京师范大学文理学院物理系）；Advanced Institute of Natural Sciences, Beijing Normal University（北京师范大学前沿科学中心）；Institute for Gravitational Wave Astronomy, Henan Academy of Sciences（河南省科学院引力波天文研究院）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Institute for Frontier in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与空间科学学院）
Cosmic CORALS: Timing the Universe with high-z star clusters
Università di Bologna（博洛尼亚大学）；INAF - Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天文与空间科学观测站）；Université de Genève（日内瓦大学）；ETH Zurich（苏黎世联邦理工学院）；University of Barcelona（巴塞罗那大学）；ICREA（加泰罗尼亚高级研究学院）；IEEC, Institut d’Estudis Espacials de Catalunya（加泰罗尼亚空间研究院）
