NANOGrav 15年数据集：基于VLBI星象先验的精度提升
高能天体物理现象
2025-10-06 v2 天体物理仪器与方法
摘要
精确的脉冲星星象估计在几乎所有高精度脉冲星计时实验中发挥着 essential 作用。传统的脉冲星计时技术通过在拟合观测脉冲到达时间测量值的模型时将其作为自由参数来细化这些估计。然而，可靠的亚毫弧秒级星象估计需要多年的观测，即便如此，红噪声的能量也可能被错误地吸收到星象参数拟合中，从而偏导最终的估计并降低我们对红噪声过程（包括引力波）的灵敏度。在本工作中，我们通过使用来自长基线干涉仪（VLBI）派生的脉冲星星象估计作为计时拟合的先验来缓解这些短板。首先，我们校准了一种框架绑定，以消除VLBI和计时参考系之间的偏移。然后，我们使用VLBI信息先验和几个与两种技术都一致的星象解的计时似然性，获得最大后验星象解。我们发现了我们结果与基于计时的星象解之间的偏差，如果这些偏差是真实的，将导致在单源引力波搜索中感兴趣频率的频谱功率被吸收。然而，我们在引力波背景的低频域没有发现显著的星象拟合功率吸收。
引用
@article{arxiv.2509.21203,
title = {The NANOGrav 15-Year Data Set: Improved Timing Precision With VLBI Astrometric Priors},
author = {Sofia V. Sosa Fiscella and Michael T. Lam and Gabriella Agazie and Akash Anumarlapudi and Anne M. Archibald and Zaven Arzoumanian and Paul T. Baker and Paul R. Brook and H. Thankful Cromartie and Kathryn Crowter and Maria Silvina De Biasi 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 Jeffrey S. Hazboun and Ross J. Jennings and Megan L. Jones and David L. Kaplan and Matthew Kerr and Duncan R. Lorimer and Jing Luo and Ryan S. Lynch and Alexander McEwen and Maura A. McLaughlin and Natasha McMann and Bradley W. Meyers and Cherry Ng and David J. Nice 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 Ann Schmiedekamp and Carl Schmiedekamp and Brent J. Shapiro-Albert and Ingrid H. Stairs and Kevin Stovall and Abhimanyu Susobhanan and Joseph K. Swiggum and Haley M. Wahl},
journal= {arXiv preprint arXiv:2509.21203},
year = {2025}
}