发表机构
New Mexico Institute of Mining and Technology; National Radio Astronomy Observatory; Oregon State University; Green Bank Observatory; SETI Institute; University of Wisconsin-Milwaukee; University of North Carolina, Chapel Hill; Newcastle University; NASA Goddard Space Flight Center; Widener University; Lafayette College; Institute for Gravitational Wave Astr（新墨西哥矿业理工学院; 国家射电天文台; 俄勒冈州立大学; 格林班克天文台; SETI研究所; 威斯康星大学密尔沃基分校; 北卡罗来纳大学教堂山分校; 纽卡斯尔大学; 美国宇航局戈达德太空飞行中心; 韦德纳大学; 拉斐特学院; 引力波天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
提出一个模拟框架，用于预测脉冲星测时阵列中每颗脉冲星的最优观测仪器、频率和积分时间，应用于NANOGrav源列表，表明从头构建的DSA PTA更灵敏，且时间优化对GWB灵敏度提升约5%。
AI 中文摘要
脉冲星测时阵列（PTA）实验通过协调对毫秒脉冲星的射电测时观测，已获得纳赫兹频率引力波背景（GWB）存在的证据。随着下一代射电望远镜的投入使用，这一证据的显著性预计将增强，且GWB的起源（一个或多个）有望在持续观测中被揭示。我们提出一个框架，用于模拟一组望远镜对一组脉冲星的测时观测，以预测每颗脉冲星的最优仪器、观测频率和积分时间。我们将此方法应用于NANOGrav的85颗脉冲星源列表，这些脉冲星由绿岸望远镜、甚大阵列、加拿大氢强度测绘实验（CHIME）以及深同步阵列（DSA）观测，DSA是正在内华达州建造的射电碟形天线阵列。我们讨论了这些脉冲星测时精度的主要噪声贡献，并表明大多数并非由固有脉冲相位抖动噪声主导。我们还确定了哪些脉冲星应使用DSA和CHIME或仅使用DSA进行测时，并表明从头构建的DSA PTA比使用现有仪器的PTA更灵敏。最后，我们在固定时间预算下求解每颗脉冲星的最优积分时间，以最大化GWB信噪比。我们表明，对于使用DSA观测的这些脉冲星，优化积分时间几乎没有益处。通过PTA的蒙特卡洛实现，我们表明，与早期科学、固定源列表情况下的每源等时观测相比，时间优化观测的GWB灵敏度提高了约5%。
英文摘要
Pulsar timing array (PTA) experiments have seen evidence for a nanohertz-frequency gravitational wave background (GWB) through coordinated radio timing observations of millisecond pulsars. The significance of this evidence is expected to grow and the GWB's progenitor(s) uncovered with continued observations, especially as the next generation of radio telescopes comes online. We present a framework for simulating timing observations of a set of pulsars with a set of telescopes to predict the per-pulsar optimal instrument, observing frequency, and integration time. We apply this methodology to the NANOGrav source list of 85 pulsars observed with the Green Bank Telescope, Very Large Array, Canadian Hydrogen Intensity Mapping Experiment (CHIME), and the Deep Synoptic Array (DSA), a radio dish array under construction in Nevada. We discuss the dominant noise contributions to the timing precision of these pulsars and show that most are not dominated by intrinsic pulse phase jitter noise. We also determine which pulsars should be timed with DSA and CHIME or only DSA and show that an ab initio DSA PTA is more sensitive than one which uses current instruments. Finally, we solve for the optimal integration time per pulsar, subject to a fixed time budget, that maximizes the GWB signal-to-noise. We show that there is little benefit to optimizing over integration time for these pulsars observed with DSA. Through Monte Carlo realizations of the PTA, we show that the GWB sensitivity improves by $\sim 5\%$ for time-optimized observations compared to the equal-time-per-source scenario with an early-science, fixed source list.
Comments38 pages, 12 figures, submitted to The Astrophysical Journal
