Tidal Disruption Event Rates across Cosmic Time: Forecasts for LSST, Roman, and JWST and Their Constraints on the Supermassive Black Hole Mass Function
宇宙时间尺度上的潮汐瓦解事件率:对 LSST、Roman 和 JWST 的预测及其对超大质量黑洞质量函数的约束
Measuring the mass distribution of supermassive black holes (SMBHs) over cosmic time remains particularly challenging for the low-mass (M<SUB>∙</SUB> ≲ 10<SUP>8</SUP> M<SUB>⊙</SUB>) population at z > 1. This population is also the most sensitive to SMBH seeding and early growth models. In this work, we construct a semiempirical model for the redshift evolution of the tidal disruption event (TDE) rate under multiple SMBH mass function prescriptions, and show that the observed redshift-dependent rate of TDEs is very sensitive to the SMBH mass function and its evolution with redshift. We further incorporate galaxy-scale processes that evolve with redshift—namely, increasing galaxy nuclear stellar densities, enhanced galaxy─galaxy merger rates, dust obscuration, and a possible top-heavy initial mass function at early cosmic times—and quantify their combined impact on the TDE rate. We find that including these effects generally results in a volumetric TDE rate that increases with redshift until a maximum near cosmic noon, before declining at higher redshift, where SMBHs that can disrupt stars become increasingly scarce. We forecast TDE rates in the Rubin Legacy Survey of Space and Time (LSST) and the Roman High Latitude Time Domain Survey, alongside expectations for serendipitous TDE rates in the JWST COSMOS-Web survey. Finally, we provide a methodology for using a flux-limited survey of TDEs in LSST to directly constrain the redshift evolution of the SMBH mass function.
展开 ▾首次系统性地将星系核密度、合并率、尘埃消光及 IMF 演化等红移依赖的星系过程纳入 TDE 率计算;揭示不同 SMBH 质量函数模型在 z>1 的 TDE 率差异可达一个量级,并给出利用 LSST 年探测总数与中值红移直接约束 BHMF 斜率的前景。
该工作以本地 TDE 光度函数(Yao+ 2023)为起点,结合对比鲜明的 SMBH 质量函数模型(Shankar+ 2009 半经验模型与 Genel+ 2014 Illustris 模拟),并进一步引入星系核密度、合并率及尘埃消光等随红移演化的效应,构建了半经验 TDE 红移演化率模型。相较于早期仅依赖 BHMF 的预测(如 Kochanek 2016),本文发现星系尺度过程在 z∼2 宇宙正午前后显著增强 TDE 率,且不同 BHMF 模型在 z>1 的预测差异可达一个量级。展望未来,LSST 年探测数千 TDE 的流量限制样本,配合 Roman 和 JWST 的高红移覆盖,将能够通过总探测数和样本中值红移直接约束低质量端 SMBH 质量函数的红移演化,为 SMBH 种籽与增长研究提供全新观测窗口。
预印本 2026-02-04 · 接收 2026-06-05 · 刊出 2026-07-14 · 收录 2026-07-22