Tidal Dissipation and Evolution of Stars Around Massive Black Holes: An Eccentric Path to Tidal Disruption

潮汐消散和大质量黑洞周围恒星的演化：潮汐瓦解的怪异路径

• 批准号: 1715246
• 负责人: Dong Lai
• 金额: $ 55.46万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1715246&HistoricalAwards=false
• 关键词: Tidal; Dissipation; Evolution; Stars; Around

Tidal disruption events (TDEs) occur when a star passes close to a massive black hole (MBH) and is torn apart by tidal forces. These events produce luminous, short-lived flares, which can be observed from Earth. Most "normal" TDEs occur when the star passes within the tidal radius of the MBH, leading to a one-time shredding of the star. However, it is possible that stars are captured into highly eccentric orbits with closest approach distance larger than the tidal radius. These stars will not be immediately disrupted but will undergo multiple tidal encounters with the MBH.  A research team at Cornell University will study the physics of such encounters, including the oscillations and waves set up in the star, and then use powerful computer models to determine how the evolution of the star and its orbit around the MBH are affected and whether the star will ultimately be torn apart.  The research team will include both graduate and undergraduate students and will produce visualizations and animations of the results for use in educational and outreach programs.The research team will study a new regime for TDEs, involving multiple pericenter passages of a star with a MBH, leading to a qualitatively different evolutionary path toward tidal disruption and a potentially distinct observational signature.  The projects that will be undertaken range from well-defined to exploratory and the work has the potential to lead to new discoveries. The research will enhance the understanding of the interaction between stars and MBHs at the centers of galaxies and will help interpret ongoing and future observations of luminous transient sources.

当一颗星星靠近一个大质量黑洞（MBH）时，就会发生潮汐破裂事件（TDE），并被潮汐力撕裂。 这些事件产生明亮的，短暂的耀斑，可以从地球上观察到。 大多数“正常”的TDE发生在星星经过MBH的潮汐半径时，导致星星一次性粉碎。 然而，有可能恒星被捕获到高度偏心的轨道上，最近的接近距离大于潮汐半径。 这些恒星不会立即被破坏，但会与MBH发生多次潮汐相遇。康奈尔大学的一个研究小组将研究这种相遇的物理学，包括星星中产生的振荡和波，然后使用强大的计算机模型来确定星星的演化及其围绕MBH的轨道如何受到影响，以及星星最终是否会被撕裂。 该研究小组将包括研究生和本科生，并将产生可视化和动画的结果，用于教育和推广计划。研究小组将研究一个新的制度，为TDEs，涉及多个近心通道的星星与MBH，导致潮汐破坏的性质不同的演化路径和可能不同的观测信号。将进行的项目范围从明确的探索和工作有可能导致新的发现。 这项研究将加强对星系中心恒星和MBH之间相互作用的理解，并将有助于解释正在进行的和未来的发光瞬态源观测。