Elucidating the Diversity of Outflows in Tidal Disruption Events

人们早就知道，星系中心超大质量黑洞（SMBH）的巨大气体流出与星系本身的环境之间的反馈在星系演化中起着关键作用。 然而，这些外流的机制和SMBH吸积的确定模型仍然难以捉摸。 当一颗星星被分散到一个穿过SMBH潮汐半径的轨道上时，研究这些现象的一个重要机会就出现了，当SMBH消耗来自被破坏的星星的气体时，吸积率暂时增加了几个数量级。 来自亚利桑那大学的一个研究小组将利用这些潮汐破坏事件（TDEs）的无线电观测，结合补充的多波长数据，对当地宇宙中SMBH的质量喷射进行首次系统调查。 该项目还包括通过与佛兰德劳天文馆和科学中心的伙伴关系，为提高公众对天文学的认识而作出的一些相关努力。 这些活动将包括公开讲座，当地一级学校学生的实地考察，以及为期一周的5-6年级儿童夏令营，重点是黑洞。研究小组将通过对流出物和周围星际介质之间的冲击产生的无线电同步辐射的无线电和毫米波观测来跟踪TDE流出物的演变。 同步加速器无线电发射的建模将使研究人员能够计算流出物携带的能量，环境介质的密度分布以及其他难以通过观测测量的物理参数。这些计算反过来又为TDEs的数值模拟提供了信息，并为喷流、激波、吸积流和SMBH反馈提供了重要的物理见解。在过去的三年里，TDEs的发现率已经增加到每年大约10个，这为对统计上重要的人群进行系统的无线电研究提供了机会。该奖项反映了NSF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。

It has long been known that feedback between immense outflows of gas from supermassive black holes (SMBHs) in the center of galaxies and the environment of the galaxies themselves plays a key role in galaxy evolution. However, the mechanism by which these outflows are launched and a definitive model of SMBH accretion have remained elusive. An important opportunity to study these phenomena occurs when a star is scattered onto an orbit that crosses the SMBH’s tidal radius, temporarily increasing the accretion rate by orders of magnitude as the SMBH consumes gas from the disrupted star. A research team from the University of Arizona will use radio observations of these tidal disruption events (TDEs) in combination with supplemental multi-wavelength data to conduct the first systematic investigation of mass ejection from SMBHs in the local Universe. The project also includes a number of related efforts to increase public awareness of astronomy through a partnership with the Flandrau Planetarium and Science Center. These will include public talks, field trips for students from local Title I schools, and a one-week summer camp for children in grades 5-6 focused on black holes. The research team will track the evolution of TDE outflows via radio and millimeter observations of the radio synchrotron emission produced in the shock between the outflow and the ambient interstellar medium. Modeling of the synchrotron radio emission will allow the researchers to calculate the energy carried by the outflow, the density profile of the ambient medium, and other physical parameters that are otherwise difficult to measure observationally. These calculations in turn inform numerical simulations of TDEs and provide critical physical insight into jets, shocks, accretion flows, and SMBH feedback. In the past three years, the discovery rate of TDEs has increased to roughly 10 per year, providing an opportunity to conduct a systematic radio study of a statistically significant population.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.