Collaborative Research: The Radiation Magnetohydrodynamics of Tidal Disruption Events

潮汐破坏事件（TDE）是一种天体物理现象，当一颗恒星足够接近一个超大质量黑洞（SMBH）时，就会被黑洞的潮汐力拉开。当这种情况发生时，恒星的部分质量被黑洞周围的吸积盘捕获，当这些物质落入黑洞时，它会加速，产生电磁辐射，这可以被天文望远镜探测到。为了更好地研究这些可以帮助科学家理解强引力场、星系核心周围空间和吸积物理的事件，威斯康星大学密尔沃基分校和弗吉尼亚大学之间的一项研究合作将使用数值模拟来探测tde的辐射磁流体动力学（研究高磁化等离子体的发射）以及物理如何通过观测特征表现出来。研究人员还将为学生和社区提供外展和教育机会，包括在密尔沃基的曼弗雷德奥尔森天文馆进行演讲，在计算科学暑期学校授课，并在VA-NC联盟和UVA-Spelman交换暑期项目中指导本科生，目的是增加代表性不足的群体在STEM研究领域的参与。研究人员将使用数字代码MANGA和Athena++，他们已经为此进行了大量的算法投资，并且它们是这种tde的理想数值模拟。研究人员将真实地模拟恒星从最初的破坏到后退和随后的吸积的潮汐破坏。特别是，他们将确定磁场和辐射压力如何影响恒星破裂产生的潮汐流，驱动流-流碰撞的演变，并影响随后对黑洞的吸积，从而使他们能够探索TDE事件中超级爱丁顿吸积的物理学及其观测特征。这项工作对于解释在不久的将来将通过当前的瞬态调查和维拉鲁宾天文台发现的大量事件至关重要。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

A tidal disruption event (TDE) is an astrophysical phenomenon that occurs when a star approaches sufficiently close to a supermassive black hole (SMBH) to be pulled apart by the black hole’s tidal force. As this happens, part of the star’s mass is captured in an accretion disk around the black hole (BH), and as this matter falls into the black hole, it accelerates, generating electromagnetic radiation, which can be detected by astronomical telescopes. To better study these events, which can help scientists understand strong gravitational fields, the space around the cores of galaxies, and physics of accretion, a research collaboration between the University of Wisconsin-Milwaukee and the University of Virginia will use numerical simulations to probe the radiation magnetohydrodynamics (the study of emission from highly magnetized plasmas) of TDEs and how the physics is manifest through observational signatures. The investigators will also provide outreach and educational opportunities for students and the community, including presentations at the Manfred Olson Planetarium in Milwaukee, teaching at a summer school in computational science, and mentoring undergraduate students in the VA-NC Alliance and UVA-Spelman exchange summer programs, with the goal of increasing participation of underrepresented groups in STEM research fields.The investigators will use the numerical codes MANGA and Athena++, for which they have made significant algorithmic investments, and which are ideal for numerical simulations of this TDEs. The investigators will realistically model the tidal disruption of stars from initial disruption to fallback and subsequent accretion. In particular, they will determine how magnetic fields and radiation pressure affect the tidal streams from the star’s disruption, drive the evolution of stream-stream collisions, and impact the subsequent accretion onto the black hole, allowing them explore the physics of super-Eddington accretion in TDE events and their observational signatures. This work is crucial for the intepretation of the the large number of events that will be discovered with the current transient surveys and the Vera Rubin Observatory in the near future.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.