The NANOGrav 15 Yr Data Set: Removing Pulsars One by One from the Pulsar Timing Array
Abstract
Evidence has emerged for a stochastic signal correlated among 67 pulsars within the 15-year pulsar-timing data set compiled by the NANOGrav collaboration. Similar signals have been found in data from the European, Indian, Parkes, and Chinese PTAs. This signal has been interpreted as indicative of the presence of a nanohertz stochastic gravitational wave background. To explore the internal consistency of this result we investigate how the recovered signal strength changes as we remove the pulsars one by one from the data set. We calculate the signal strength using the (noise-marginalized) optimal statistic, a frequentist metric designed to measure correlated excess power in the residuals of the arrival times of the radio pulses. We identify several features emerging from this analysis that were initially unexpected. The significance of these features, however, can only be assessed by comparing the real data to synthetic data sets. After conducting identical analyses on simulated data sets, we do not find anything inconsistent with the presence of a stochastic gravitational wave background in the NANOGrav 15-year data. The methodologies developed here can offer additional tools for application to future, more sensitive data sets. While this analysis provides an internal consistency check of the NANOGrav results, it does not eliminate the necessity for additional investigations that could identify potential systematics or uncover unmodeled physical phenomena in the data.
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Cite
@article{arxiv.2411.14846,
title = {The NANOGrav 15 Yr Data Set: Removing Pulsars One by One from the Pulsar Timing Array},
author = {Gabriella Agazie and Akash Anumarlapudi and Anne M. Archibald and Zaven Arzoumanian and Jeremy G. Baier and Paul T. Baker and Bence Becsy 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 Tyler Cohen and James M. Cordes and Neil J. Cornish and Fronefield Crawford and H. Thankful Cromartie and Kathryn Crowter and Megan E. DeCesar and Paul B. Demorest and Heling Deng and Lankeswar Dey and Timothy Dolch and Elizabeth C. Ferrara and William Fiore and Emmanuel Fonseca and Gabriel E. Freedman and Emiko C. Gardiner and Nate Garver-Daniels and Peter A. Gentile and Kyle A. Gersbach and Joseph Glaser and Deborah C. Good and Lydia Guertin and Kayhan Gultekin and Jeffrey S. Hazboun and Ross J. Jennings and Aaron D. Johnson and Megan L. Jones and Andrew R. Kaiser and David L. Kaplan and Luke Zoltan Kelley and Matthew Kerr and Joey S. Key and Nima Laal and Michael T. Lam and William G. Lamb and Bjorn Larsen and T. Joseph W. Lazio and Natalia Lewandowska 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 Patrick M. Meyers and Hannah Middleton and Chiara M. F. Mingarelli and Andrea Mitridate and Christopher J. Moore 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 Jessie C. Runnoe and Alexander Saffer 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 Alberto Vecchio and Sarah J. Vigeland and Haley M. Wahl and Caitlin A. Witt and David Wright and Olivia Young},
journal= {arXiv preprint arXiv:2411.14846},
year = {2025}
}
Comments
21 pages, 11 figures, 2 tables