发表机构
University of Science and Technology of China; Central China Normal University; Guizhou University（中国科学技术大学; 华中师范大学; 贵州大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究在光学余辉存在时为广角巡天望远镜识别千新星的问题，利用基于费舍尔信息矩阵的数值框架模拟，发现识别受距离限制，提出分阶段观测策略，可提高识别精度，为优化观测资源提供物理基础。
AI 中文摘要
识别与双中子星合并相关的千新星通常因占主导的同步辐射余辉而变得复杂。在这项工作中，我们评估了广角巡天望远镜（WFST）在识别余辉 - 千新星复合瞬变中的千新星信号方面的性能。使用基于费舍尔信息矩阵的数值框架，我们针对两种情况各模拟了10000次实现：基于AT2017gfo的模板模型和考虑千新星多样性的物理采样总体。结果表明千新星识别主要受源距离限制。在两种情况下，识别效率对余辉微观物理参数的变化基本不敏感，对于类似AT2017gfo的事件，在约600 Mpc内的距离处识别效率超过80%。在我们采用的假设下，估计WFST每年可识别约1 - 16颗千新星。此外，发现基于颜色的滤光片的辨别能力迅速饱和，在合并后的第二晚达到稳定平台期。因此我们提出一种分阶段观测策略，在第一晚优先进行高 cadence的g和r波段监测，并从第二晚起纳入z波段。该策略通过利用千新星产生日益突出的红超量来提高识别精度。我们的结果为在多信使时代优化WFST观测资源以有效探测和表征千新星提供了物理基础。
英文摘要
Identifying kilonovae associated with binary neutron star mergers is often complicated by the presence of a dominant synchrotron afterglow. In this work, we evaluate the performance of the Wide Field Survey Telescope (WFST) in identifying kilonova signals in composite afterglow-kilonova transients. Using a numerical framework based on the Fisher information matrix, we simulate $10,000$ realizations for each of two scenarios: an AT2017gfo-based template model and a physically sampled population that accounts for kilonova diversity. Our results indicate that kilonova identification is primarily limited by source distance. In both scenarios, the identification efficiency is largely insensitive to variations in afterglow microphysical parameters and exceeds $80\%$ at distances within approximately $600~\rm Mpc$ for AT2017gfo-like events. Under our adopted assumptions and a short gamma-ray burst (sGRB)-triggered target-of-opportunity (ToO) observational strategy, we estimate that the WFST could identify $0.1-1.2$ kilonovae per year in the optimistic scenario. Furthermore, we find that the discriminating power of color-based filters rapidly saturates, reaching a stable plateau by the second night after the merger. We therefore propose a staged observing strategy that prioritizes high-cadence $g$ and $r$-band monitoring during the first night and incorporates the $z$ band from the second night onward. This strategy improves the identification precision by exploiting the increasingly prominent red excess produced by the kilonova. Our results provide a physical basis for optimizing WFST observing resources to efficiently detect and characterize kilonovae in the multimessenger era.
Comments26 pages, 13 figures,
