如何探测天体物理纳赫兹引力波背景
广义相对论与量子宇宙学
2023-12-05 v2 高能天体物理现象
摘要
脉冲星计时数据分析已为nHz频带中的随机引力波背景提供了证据。此类背景最可能的来源是数百万个超大质量黑洞双星的信号叠加。用于搜寻此类背景并评估其显著性的标准统计技术做了若干简化假设，即：i) 高斯性；ii) 各向同性；以及最常见地 iii) 幂律谱。然而，来自有限双星集合的随机背景并不严格满足上述任一假设。为理解这些假设的影响，我们在一大批逼真的模拟数据集上测试了标准分析技术。数据集长度、观测计划和噪声水平的选择旨在模拟NANOGrav 15年数据集。基于Illustris宇宙学流体动力学模拟的模型所生成的数百万个双星模拟信号被加入数据中。我们发现，尽管基本假设未被严格满足，标准统计方法在这些模拟数据集上表现异常出色。它们能够实现对背景的可靠探测。然而，即便在固定的天体物理参数下，宇宙的不同实现也会导致背景的显著性和恢复参数出现很大方差。我们还发现，若不考虑响亮的单个双星，其存在会偏置背景的谱恢复。
引用
@article{arxiv.2309.04443,
title = {How to Detect an Astrophysical Nanohertz Gravitational-Wave Background},
author = {Bence Bécsy and Neil J. Cornish and Patrick M. Meyers and Luke Zoltan Kelley and Gabriella Agazie and Akash Anumarlapudi and Anne M. Archibald and Zaven Arzoumanian and Paul T. Baker and Laura Blecha and Adam Brazier and Paul R. Brook and Sarah Burke-Spolaor and J. Andrew Casey-Clyde and Maria Charisi and Shami Chatterjee and Katerina Chatziioannou and Tyler Cohen and James M. Cordes and Fronefield Crawford and H. Thankful Cromartie and Kathryn Crowter and Megan E. DeCesar and Paul B. Demorest and Timothy Dolch and Elizabeth C. Ferrara and William Fiore and Emmanuel Fonseca and Gabriel E. Freedman and Nate Garver-Daniels and Peter A. Gentile and Joseph Glaser and Deborah C. Good and Kayhan Gültekin and Jeffrey S. Hazboun and Sophie Hourihane and Ross J. Jennings and Aaron D. Johnson and Megan L. Jones and Andrew R. Kaiser and David L. Kaplan and Matthew Kerr and Joey S. Key and Nima Laal and Michael T. Lam and William G. Lamb and T. Joseph W. Lazio and Natalia Lewandowska and Tyson B. Littenberg and Tingting Liu and Duncan R. Lorimer and Jing Luo and Ryan S. Lynch and Chung-Pei Ma and Dustin R. Madison and Alexander McEwen and James W. McKee and Maura A. McLaughlin and Natasha McMann and Bradley W. Meyers and Chiara M. F. Mingarelli and Andrea Mitridate and Cherry Ng and David J. Nice and Stella Koch Ocker and Ken D. Olum and Timothy T. Pennucci and Benetge B. P. Perera and Nihan S. Pol and Henri A. Radovan and Scott M. Ransom and Paul S. Ray and Joseph D. Romano and Shashwat C. Sardesai and Ann Schmiedekamp and Carl Schmiedekamp and Kai Schmitz and Brent J. Shapiro-Albert and Xavier Siemens and Joseph Simon and Magdalena S. Siwek and Sophia V. Sosa Fiscella and Ingrid H. Stairs and Daniel R. Stinebring and Kevin Stovall and Abhimanyu Susobhanan and Joseph K. Swiggum and Stephen R. Taylor and Jacob E. Turner and Caner Unal and Michele Vallisneri and Rutger van Haasteren and Sarah J. Vigeland and Haley M. Wahl and Caitlin A. Witt and Olivia Young},
journal= {arXiv preprint arXiv:2309.04443},
year = {2023}
}
备注
14 pages, 8 figures, version matching published paper