{"paper":{"title":"A Gamma-ray Pulsar Timing Array Constrains the Nanohertz Gravitational Wave Background","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. Berretta, A. Dom\\'inguez, A. Fiori, A. Franckowiak, A. K. Harding, A. Manfreda, A. Morselli, A. Parthasarathy, A. Reimer, B. Bhattacharyya, B. Rani, C. J. Clark, C. Sgr\\`o, D. A. Smith, D. Bastieri, D. F. Torres, D. Gasparrini, D. Green, D. Horan, D. J. Suson, D. Paneque, D. Serini, E. Bissaldi, E. Bloom, E. Burns, E. Cavazzuti, E. C. Ferrara, E. Hays, E. J. Siskind, E. Orlando, E. Troja, F. D'Ammando, F. d. Palma, F. Fan. Dirirsa, F. Gargano, F. Giordano, F. Longo, F. Loparco, G. Barbiellini, G. J\\'ohannesson, G. Mart\\'i-Devesa, G. Principe, G. Spandre, G. Theureau, G. Zaharijas, H. Cromartie, H. Poon, I. A. Grenier, I. Cognard, I.Mereu, I. Stairs, J. Ballet, J. B. Thayer, J. Coronado-Bl\\'azquez, J. F. Ormes, J. Li, J. L. Racusin, J. Roy, J. Scargle, J. Valverde, J.W. Hewitt, K. Crowter, K. Wood, L. Baldini, L. D. Venere, L. Guillemot, L. Latronico, L. Nieder, L. Scotton, M. Ajello, M. Crnogorcevic, M. E. Monzani, M. Giroletti, M. Gustafsson, M. J. Keith, M. Kerr, M. Kramer, M. Kuss, M. Negro, M. N. Lovellette, M. N. Mazziotta, M. Orienti, M. Persic, M. Pesce-Rollins, M. Razzano, M. S\\'anchez-Conde, N. Cibrario, N. D. Lalla, N. Giglietto, N. Mirabal, N. Omodei, O. Reimer, P. A. Caraveo, P. Bruel, P. F. Michelson, P. Fusco, P. Lubrano, P. M. Sa. Parkinson, P. Spinelli, P. S. Ray, R. A. Cameron, R. Bellazzini, R. Bonino, R. Buehler, R. D. Blandford, R. Ojha, R. Pillera, R. Rando, R. Spiewak, S. Buson, S. Ciprini, S. Cutini, S. D. Gaetano, S. Funk, S. Guiriec, S. J. Swihart, S. Larsson, S. Maldera, S. M. Ransom, S. Rain\\`o, S. Razzaque, S. Tabassum, S. W. Digel, T. A. Porter, T. Mizuno, V. Gammaldi, W. B. Atwood, W. Mitthumsiri, X. Hou, Y. Fukazawa, Z. Pei, Z. Wadiasingh","submitted_at":"2022-04-11T16:15:37Z","abstract_excerpt":"After large galaxies merge, their central supermassive black holes are expected to form binary systems whose orbital motion generates a gravitational wave background (GWB) at nanohertz frequencies. Searches for this background utilize pulsar timing arrays, which perform long-term monitoring of millisecond pulsars (MSPs) at radio wavelengths. We use 12.5 years of Fermi Large Area Telescope data to form a gamma-ray pulsar timing array. Results from 35 bright gamma-ray pulsars place a 95\\% credible limit on the GWB characteristic strain of $1.0\\times10^{-14}$ at 1 yr$^{-1}$, which scales as the o"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2204.05226","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2204.05226/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}