By means of N-body/SPH simulations we investigate the morphological properties of thick disks formed through minor mergers. We show that the vertical surface density profile of the post-merger thick disk follows a sech function and has an excess in the regions far from the disk mid-plane (z>2kpc). This stellar excess also follows a sech function with a larger scale height than the main thick disk component, and it is usually dominated by stars from the primary galaxy. Stars in the excess have a rotational velocity lower than that of stars in the thick disk, and they may thus be confused with stars in the inner galactic halo. The thick disk scale height increases with radius and the rate of its increase is smaller for more gas rich primary galaxies. On the contrary, the scale height of the stellar excess is independent of both radius and gas fraction. We also find that the post-merger thick disk has a radial scale length which is 10-50% larger than that of the thin disk. Two consecutive mergers have basically the same effect on heating the stellar disk as a single merger of the same total mass. To investigate how thick disks produced through secular processes may differ from those produced by minor mergers, we also simulated gravitationally unstable gas-rich disks. These disks do not produce either a stellar excess or a ratio of thick to thin disk scale lengths greater than one. Our simulation results are consistent with observations of the ratio of thick to thin disk scale lengths of the Milky Way and nearby galaxies, and with the Toomre diagram of the Milky Way. We conclude that minor mergers are a viable mechanism for the creation of galactic thick disks and investigating stars at several kpc above the mid-plane of the Milky Way and other galaxies may provide a quantitative method for studying the minor merger history of galaxies.
Lithium abundance and stellar rotation in the Galactic halo and thick disc: Contribution from low-mass giant field stars
Observatório Nacional（国家天文台）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙科学理事会-国家航空航天技术研究所）；Instituto de Astrofísica de Andalucía, CSIC（安达卢西亚天体物理研究所，西班牙科学理事会）；Observatorio Astronómico de Córdoba, Universidad Nacional de Córdoba（科尔多瓦天文台，科尔多瓦国立大学）；Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)（国家科学研究委员会）
Kinematic scaling of thin and thick discs from SAMI to NewHorizon
Yonsei University（延世大学）；CSIRO Space & Astronomy（澳大利亚联邦科学与工业研究组织空间与天文部）；Australian National University（澳大利亚国立大学）；The University of Sydney（悉尼大学）；Institut d’Astrophysique de Paris, CNRS and Sorbonne Université（巴黎天体物理研究所，法国国家科学研究中心和索邦大学）；Kyung Hee University（庆熙大学）
该研究利用 SAMI 星系和 NewHorizon 模拟数据，通过施瓦兹席尔德轨道叠加等方法，重新审视盘状恒星质量与速度弥散关系并扩展到薄厚盘，揭示了相关结果及系统误差，为未来研究盘状子结构提供方向。
The Spheroidal Bulge of the Milky Way: Chemodynamically Distinct from the Inner-Thick Disc and Bar
Leibniz-Institut für Astrophysik Potsdam (AIP)（波茨坦莱布尼茨天体物理研究所）；Universität Potsdam（波茨坦大学）；Universidad Nacional Autónoma de México（墨西哥国立自治大学）；Instituto de Astronomía, Universidad Nacional Autónoma de México（墨西哥国立自治大学天文研究所）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Universidad de La Laguna（拉古纳大学）；Max Planck Institute for Astronomy（马克斯·普朗克天体物理研究所）；Universitat de Barcelona（巴塞罗那大学）；Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona（巴塞罗那大学宇宙科学研究所）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究学院）
Through Thick and Thin: The Cosmic Evolution of Disk Scale Height
Xiamen University（厦门大学）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo（东京大学宇宙物理与数学研究所（WPI））；The Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学柯利天文与天体物理研究所）；Department of Astronomy, Peking University（北京大学天文学系）；Department of Astronomy, School of Science, The University of Tokyo（东京大学理学部天文学系）；Center for Data-Driven Discovery, Kavli IPMU (WPI), UTIAS, The University of Tokyo（东京大学UTIAS数据驱动发现中心）；Center for Astrophysical Sciences, Department of Physics & Astronomy, Johns Hopkins University（约翰霍普金斯大学物理与天文学系天体科学中心）
Dissecting the 3D chemo-dynamical structures of NGC~1381: A galaxy hosting an ancient slow bar with an accretion-related bulge and thick disc
Westlake University（西湖大学）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Astrophysics Research Institute, Liverpool John Moores University（利物浦约翰摩尔斯大学天体物理研究所）；Instituto de Astrofísica de Canarias（加那利天体物理学研究所）；Departamento de Astrofísica, Universidad de La Laguna（拉帕尔马大学天体物理学系）；Department of Astrophysics, University of Vienna（维也纳大学天体物理学系）
