Year: 2025
Type: article
Abstract: Pulse profile stability is a central assumption of standard pulsar timing methods. Thus, it is important for pulsar timing array experiments such as the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) to account for any pulse profile variability present in their data sets. We show that in the NANOGrav 15 yr data set, the integrated pulse profile of PSR J1022+1001 as seen by the Arecibo radio telescope at 430, 1380, and 2030 MHz varies considerably in its shape from observation to observation. We investigate the possibility that this is due to the “ideal feed assumption” (IFA), on which NANOGrav’s routine polarization calibration procedure relies. PSR J1022+1001 is ∼90% polarized in one pulse profile component, and also has significant levels of circular polarization. Time-dependent deviations in the feed’s polarimetric response (PR) could cause mixing between the intensity I and the other Stokes parameters, leading to the observed variability. We calibrate the PR using a mixture of measurement equation modeling and measurement equation template matching techniques. The resulting profiles are no less variable than those calibrated using the IFA method, nor do they provide an improvement in the timing quality of this pulsar. We observe the pulse shape in 25 MHz bandwidths to vary consistently across the band, which cannot be explained by interstellar scintillation in combination with profile evolution with frequency. Instead, we favor phenomena intrinsic to the pulsar as the cause.
Source: The Astrophysical Journal
Authors: William Fiore, Maura A. McLaughlin, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Paul R. Brook, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Lankeswar Dey, Timothy Dolch, Elizabeth C. Ferrara, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Jeffrey S. Hazboun, Ross J. Jennings, Megan L. Jones, David L. Kaplan, Matthew Kerr, Michael T. Lam, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Alexander McEwen, Natasha McMann, Bradley W. Meyers, Cherry Ng, David J. Nice, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Ann Schmiedekamp, Carl Schmiedekamp, Brent J. Shapiro-Albert, Ingrid H. Stairs, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Haley M. Wahl
Institutions: West Virginia University, University of British Columbia, University of Wisconsin–Milwaukee, Newcastle University, Goddard Space Flight Center, Widener University, University of Birmingham, National Academy of Sciences, National Academies of Sciences, Engineering, and Medicine, George Mason University, National Radio Astronomy Observatory, Hillsdale College, Eureka Scientific, University of Maryland, College Park, University of Montana, Oregon State University, United States Naval Research Laboratory, Naval Research Laboratory Space Science Division, Rochester Institute of Technology, Search for Extraterrestrial Intelligence, University of Toronto, Vanderbilt University, Curtin University, International Centre for Radio Astronomy Research, Lafayette College, Eötvös Loránd University, Arecibo Observatory, University of Puerto Rico-Mayaguez, Pennsylvania State University, United States Army, Max Planck Institute for Gravitational Physics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, Vanderbilt University, Canadian Institute for Advanced Research, University of Central Florida, University of Toronto, Eötvös Loránd Tudományegyetem, Goddard Space Flight Center, Natural Sciences and Engineering Research Council of Canada, Science and Technology Facilities Council, Office of Naval Research
Awards: NANOGrav@UPRM: Growing and Characterizing the NANOGrav Gravitational-Wave Detector, G118299772, NANOGrav Physics Frontier Center, G201248631, AccelNet-Implementation: The International Pulsar Timing Array, WOU-MMA: Probing Supermassive Binary Black Holes with Pulsar Timing Arrays, Astrophysics at the University of Birmingham - Consolidated grant 2022-2025, G4961910479, RII Track-1: Gravitational Wave Astronomy and the Appalachian Freshwater Initiative, Management and Operations of the Arecibo Observatory, Collaborative research: Completing the most sensitive low-frequency survey for radio pulsars and transients, The Construction of a Pulsar Interstellar Medium Array Detector, G6866600364, G7484881787, The NANOGrav Physics Frontiers Center
OpenAlex ID: W4410130929