Browse by author
Lookup NU author(s): Dr Anne ArchibaldORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2025. The Author(s). Published by the American Astronomical Society. Evidence has emerged for a stochastic signal correlated among 67 pulsars within the 15 yr pulsar-timing data set compiled by the NANOGrav collaboration. Similar signals have been found in data from the European, Indian, Parkes, and Chinese pulsar timing arrays. This signal has been interpreted as indicative of the presence of a nanohertz stochastic gravitational-wave background (GWB). 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 the 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 GWB in the NANOGrav 15 yr 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.
Author(s): Agazie G, Anumarlapudi A, Archibald AM, Arzoumanian Z, Baier JG, Baker PT, Becsy B, Blecha L, Brazier A, Brook PR, Burke-Spolaor S, Casey-Clyde JA, Charisi M, Chatterjee S, Cohen T, Cordes JM, Cornish NJ, Crawford F, Cromartie HT, Crowter K, DeCesar ME, Demorest PB, Deng H, Dey L, Dolch T, Ferrara EC, Fiore W, Fonseca E, Freedman GE, Gardiner EC, Garver-Daniels N, Gentile PA, Gersbach KA, Glaser J, Good DC, Guertin L, Gultekin K, Hazboun JS, Jennings RJ, Johnson AD, Jones ML, Kaiser AR, Kaplan DL, Kelley LZ, Kerr M, Key JS, Laal N, Lam MT, Lamb WG, Larsen B, Lazio TJW, Lewandowska N, Liu T, Lorimer DR, Luo J, Lynch RS, Ma C-P, Madison DR, McEwen A, McKee JW, McLaughlin MA, McMann N, Meyers BW, Meyers PM, Middleton H, Mingarelli CMF, Mitridate A, Moore CJ, Ng C, Nice DJ, Ocker SK, Olum KD, Pennucci TT, Perera BBP, Pol NS, Radovan HA, Ransom SM, Ray PS, Romano JD, Runnoe JC, Saffer A, Sardesai SC, Schmiedekamp A, Schmiedekamp C, Schmitz K, Shapiro-Albert BJ, Siemens X, Simon J, Siwek MS, Sosa Fiscella SV, Stairs IH, Stinebring DR, Stovall K, Susobhanan A, Swiggum JK, Taylor SR, Turner JE, Unal C, Vallisneri M, Vecchio A, Vigeland SJ, Wahl HM, Witt CA, Wright D, Young O
Publication type: Article
Publication status: Published
Journal: Astrophysical Journal
Year: 2025
Volume: 978
Issue: 2
Online publication date: 10/01/2025
Acceptance date: 15/11/2024
Date deposited: 27/01/2025
ISSN (print): 0004-637X
ISSN (electronic): 1538-4357
Publisher: Institute of Physics
URL: https://doi.org/10.3847/1538-4357/ad93aa
DOI: 10.3847/1538-4357/ad93aa
Altmetrics provided by Altmetric
