Collaborative Research: Tidal Disruption of Stars in Galaxy Centers: Connecting Models to Observations

合作研究：星系中心恒星的潮汐扰动：将模型与观测结果联系起来

• 批准号: 1616754
• 负责人: Daniel Kasen
• 金额: $ 28.52万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1616754&HistoricalAwards=false
• 关键词: Collaborative; Research; Tidal; Disruption; Stars

Abstract for 1615881/Ramirez-Ruiz + 1616754/Kasen1. Galaxies like our own Milky Way are vast collections of hundreds of billions of stars orbiting in a disk perhaps 100,000 light-years in diameter. Lurking in the centers of many and perhaps all galaxies are supermassive black holes?mysterious objects containing millions or billions of times as much mass as our own Sun, but crammed into a volume that would fit easily within the inner solar system. In the past few years, astronomers have discovered luminous flares emanating from the core regions of nearby galaxies. These are thought to originate from the disruption of individual stars that were orbiting so close to the black hole that they were ripped apart by its strong gravitational force. The energy emitted as the remains of the star fall into the black hole produces the luminous flare. The collaborators on this project will carry out detailed numerical modeling of these events and will make publicly available their computer codes. The collaborators also plan to make their work accessible to a wide audience by teaming experts with students in the visual arts and digital media to produce visual simulations of great power and beauty. In addition, they will participate in a strong program to recruit and mentor astronomy students from under-represented groups.2. Over the past several years, wide-field transient surveys have begun to deliver more and better data about tidal disruption events (TDEs). A TDE is produced when a star is tidally disrupted by a supermassive black hole (SMBH) in the core of a galaxy. Because the theoretical understanding of such events remains incomplete, the collaborators will bring together experts in numerical hydrodynamics and non-equilibrium radiative transfer to study how matter from the tidally disrupted star loses kinetic energy and accretes onto the SMBH, identify the radiative processes that generate the X-ray/ultraviolet/optical spectra and light curves of TDEs, develop a numerical toolset to be used in analyzing TDEs, and apply it to constrain the properties of the star and the SMBH in observed events. For TDEs with well-resolved light curves, their models will enable a better characterization of the SMBHs and the dense stellar clusters that surround them. Building upon existing strengths of the partner institutions, the collaborators will also cross-fertilize the training of computational scientists and students in the visual arts and digital media using state-of-the-art astrophysical simulations as common ground. The resulting visual products will be used to disseminate the results, help to inform the general public about science and the universe, and provide raw material for science curricula, documentaries, and astronomy presentations. The investigators will also continue their program to recruit and mentor astronomy students from under-represented groups.

摘要：1615881/Ramirez-Ruiz + 1616754/Kasen1。像我们的银河系这样的星系是由数千亿颗恒星组成的巨大集合，它们围绕着一个直径约为10万光年的圆盘运行。潜伏在许多甚至所有星系中心的都是超大质量黑洞？这些神秘的物体的质量是太阳的数百万或数十亿倍，但却被塞进了一个很容易容纳内太阳系的体积。在过去的几年里，天文学家发现了从附近星系的核心区域发出的发光耀斑。这种现象被认为是由于轨道离黑洞太近的单个恒星被黑洞的强大引力撕裂而产生的。恒星残骸落入黑洞时释放出的能量产生了明亮的耀斑。该项目的合作者将对这些事件进行详细的数值模拟，并将公开他们的计算机代码。合作者还计划通过将视觉艺术和数字媒体专业的专家与学生组成团队，制作出强大力量和美的视觉模拟，让更多的观众可以接触到他们的作品。此外，他们还将参与一项强大的计划，从代表性不足的群体中招募和指导天文学学生。在过去的几年里，大范围的瞬态调查已经开始提供更多和更好的潮汐中断事件（tde）数据。当一颗恒星被星系核心的超大质量黑洞（SMBH）潮汐破坏时，就会产生TDE。由于对这些事件的理论理解仍然不完整，合作者将汇集数值流体动力学和非平衡辐射转移方面的专家，研究潮汐破坏恒星的物质如何失去动能并吸积到SMBH上，确定产生tde的x射线/紫外/光学光谱和光曲线的辐射过程，开发用于分析tde的数值工具集。并应用它来约束观测事件中恒星和SMBH的特性。对于具有良好分辨率的光曲线的tde，它们的模型将能够更好地表征SMBHs及其周围密集的星团。在合作机构现有优势的基础上，合作者还将利用最先进的天体物理模拟作为共同点，在视觉艺术和数字媒体方面对计算科学家和学生进行交叉培训。由此产生的视觉产品将用于传播结果，帮助公众了解科学和宇宙，并为科学课程、纪录片和天文学演示提供原材料。研究人员还将继续他们的计划，从代表性不足的群体中招募和指导天文学学生。