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arXiv · 2306.16222

The NANOGrav 15-year Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries

Gabriella Agazie·Akash Anumarlapudi·Anne M. Archibald·Zaven Arzoumanian·Paul T. Baker·Bence Bécsy·Laura Blecha·Adam Brazier·Paul R. Brook·Sarah Burke-Spolaor·Robin Case·J. Andrew Casey-Clyde·Maria Charisi·Shami Chatterjee·Tyler Cohen·James M. Cordes·Neil Cornish·Fronefield Crawford·H. Thankful Cromartie·Kathryn Crowter·Megan DeCesar·Paul B. Demorest·Matthew C. Digman·Timothy Dolch·Brendan Drachler·Elizabeth C. Ferrara·William Fiore·Emmanuel Fonseca·Gabriel Freedman·Nathaniel Garver-Daniels·Peter Gentile·Joseph Glaser·Deborah Good·Kayhan Gültekin·Jeffrey Hazboun·Sophie Hourihane·Ross Jennings·Aaron D. Johnson·Megan Jones·Andrew R. Kaiser·David Kaplan·Luke Zoltan Kelley·Matthew Kerr·Joey Key·Nima Laal·Michael Lam·William G. Lamb·T. Joseph W. Lazio·Natalia Lewandowska·Tingting Liu·Duncan R. Lorimer·Jing Santiago Luo·Ryan S. Lynch·Chung-Pei Ma·Dustin Madison·Alexander McEwen·James W. McKee·Maura McLaughlin·Natasha McMann·Bradley W. Meyers·Patrick M. Meyers·Chiara M. F. Mingarelli·andrea mitridate·priya natarajan·Cherry Ng·David Nice·Stella Koch Ocker·Ken Olum·Timothy T. Pennucci·Benetge Perera·Polina Petrov·Nihan Pol·Henri A. Radovan·Scott Ransom·Paul S. Ray·Joseph Romano·Shashwat C. Sardesai·Ann Schmiedekamp·Carl Schmiedekamp·Kai Schmitz·Brent J. Shapiro-Albert·Xavier Siemens·Joseph Simon·Magdalena Siwek·Ingrid Stairs·Dan Stinebring·Kevin Stovall·Abhimanyu Susobhanan·Joseph Swiggum·Jacob Taylor·Stephen Taylor·Jacob E. Turner·Caner Unal·Michele Vallisneri·Rutger van Haasteren·Sarah J. Vigeland·Haley M. Wahl·Caitlin Witt·Olivia Young
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Abstract

Evidence for a low-frequency stochastic gravitational wave background has recently been reported based on analyses of pulsar timing array data. The most likely source of such a background is a population of supermassive black hole binaries, the loudest of which may be individually detected in these datasets. Here we present the search for individual supermassive black hole binaries in the NANOGrav 15-year dataset. We introduce several new techniques, which enhance the efficiency and modeling accuracy of the analysis. The search uncovered weak evidence for two candidate signals, one with a gravitational-wave frequency of $\sim$4 nHz, and another at $\sim$170 nHz. The significance of the low-frequency candidate was greatly diminished when Hellings-Downs correlations were included in the background model. The high-frequency candidate was discounted due to the lack of a plausible host galaxy, the unlikely astrophysical prior odds of finding such a source, and since most of its support comes from a single pulsar with a commensurate binary period. Finding no compelling evidence for signals from individual binary systems, we place upper limits on the strain amplitude of gravitational waves emitted by such systems.

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Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Robin Case, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan DeCesar, Paul B. Demorest, Matthew C. Digman, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel Freedman, Nathaniel Garver-Daniels, Peter Gentile, Joseph Glaser, Deborah Good, Kayhan Gültekin, Jeffrey Hazboun, Sophie Hourihane, Ross Jennings, Aaron D. Johnson, Megan Jones, Andrew R. Kaiser, David Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey Key, Nima Laal, Michael Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Santiago Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin Madison, Alexander McEwen, James W. McKee, Maura McLaughlin, Natasha McMann, Bradley W. Meyers, Patrick M. Meyers, Chiara M. F. Mingarelli, andrea mitridate, priya natarajan, Cherry Ng, David Nice, Stella Koch Ocker, Ken Olum, Timothy T. Pennucci, Benetge Perera, Polina Petrov, Nihan Pol, Henri A. Radovan, Scott Ransom, Paul S. Ray, Joseph Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena Siwek, Ingrid Stairs, Dan Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph Swiggum, Jacob Taylor, Stephen Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Rutger van Haasteren, Sarah J. Vigeland, Haley M. Wahl, Caitlin Witt, Olivia Young. 2023-06-28. The NANOGrav 15-year Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries. https://doi.org/10.3847/2041-8213%2Face18a

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