{"paper":{"title":"Observational constraints on the spin/anisotropy of the CCOs of Cassiopeia A, Vela Jr. and G347.3-0.5 and a single surviving continuous gravitational wave candidate","license":"http://creativecommons.org/licenses/by/4.0/","headline":"A deep volunteer search sets the tightest limits yet on neutron star ellipticity and crustal anisotropy in three supernova remnants, leaving one candidate signal.","cross_cats":["hep-ph"],"primary_cat":"gr-qc","authors_text":"Bernd Machenschalk, B. McGloughlin, B. Steltner, Heinz-Bernd Eggenstein, Jing Ming, J. Martins, Maria Alessandra Papa, M. Bensch, R. Prix, V. Dergachev","submitted_at":"2025-12-17T18:24:20Z","abstract_excerpt":"We carry out the deepest and broadest search for continuous gravitational-wave signals from three neutron stars at the center of the supernova remnants Cassiopeia A, Vela Jr., and G347.3-0.5. This search was made possible by the computing power shared by thousands of Einstein@Home volunteers. After the initial Einstein@Home search, which used O3a data, we perform a multi-stage follow-up of the most promising $\\approx$ 45 million signal candidates. In the last stages, we use independent data (O3b and O4a) to further investigate the remaining candidates from the previous stages. We set the most "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We set the most stringent constraints to date on the gravitational-wave amplitude, equatorial ellipticity, r-mode saturation amplitude, and -- for the first time -- the neutron-star crustal anisotropy.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That any real continuous-wave signal from these sources would survive the multi-stage follow-up using O3b and O4a data without being rejected by the vetoes or statistical thresholds applied.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"New upper limits on gravitational-wave amplitude, ellipticity below 4e-7 for fast spins, and crustal anisotropy below 5e-3 for 1.3-100 ms periods from Cas A, Vela Jr., and G347.3-0.5, plus one surviving candidate.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A deep volunteer search sets the tightest limits yet on neutron star ellipticity and crustal anisotropy in three supernova remnants, leaving one candidate signal.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"e48cd38d09356ca87ce65638f8dcb06136fe9243b806debba72d602e396252f2"},"source":{"id":"2512.15672","kind":"arxiv","version":3},"verdict":{"id":"5496ddea-9c43-4ae3-954c-930b231c2109","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-16T21:27:48.481614Z","strongest_claim":"We set the most stringent constraints to date on the gravitational-wave amplitude, equatorial ellipticity, r-mode saturation amplitude, and -- for the first time -- the neutron-star crustal anisotropy.","one_line_summary":"New upper limits on gravitational-wave amplitude, ellipticity below 4e-7 for fast spins, and crustal anisotropy below 5e-3 for 1.3-100 ms periods from Cas A, Vela Jr., and G347.3-0.5, plus one surviving candidate.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That any real continuous-wave signal from these sources would survive the multi-stage follow-up using O3b and O4a data without being rejected by the vetoes or statistical thresholds applied.","pith_extraction_headline":"A deep volunteer search sets the tightest limits yet on neutron star ellipticity and crustal anisotropy in three supernova remnants, leaving one candidate signal."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2512.15672/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":3,"sample":[{"doi":"","year":null,"title":"\" * write output.state after.block = add.period write newline","work_id":"1504260c-aa52-462f-b8f7-4139a0d8fa4e","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":null,"title":"write newline","work_id":"927897d8-535d-410a-9cd3-bd25f995a94f","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"10.1103/physrevd.70.082001","year":2017,"title":"GWTC-4.0: Updating the Gravitational-Wave Transient Catalog with Observations from the First Part of the Fourth LIGO-Virgo-KAGRA Observing Run","work_id":"373a2c61-2309-4528-87c8-9053657b5ebd","ref_index":3,"cited_arxiv_id":"2508.18082","is_internal_anchor":true}],"resolved_work":3,"snapshot_sha256":"43844a92bdd20bef39d6208b005e8a1e600a650d2ae1c3f0de3894b7dcab98a7","internal_anchors":1},"formal_canon":{"evidence_count":1,"snapshot_sha256":"ffeb612be13f5e77ff2e23640f3174bf03c56f0941a84f500e43aa719b3d7479"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}