{"paper":{"title":"The Very Late Time Afterglow of GW170817 Favors a Wobbling Jet","license":"http://creativecommons.org/licenses/by/4.0/","headline":"A wobbling jet that drags a ring on the sky explains the shallow late afterglow of GW170817 without extra components.","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Aman Katira, Da-Ming Wei, Hao Wang, Lei Lei, Muskan Yadav, Ore Gottlieb, Yi-Zhong Fan","submitted_at":"2026-05-13T16:04:26Z","abstract_excerpt":"GW170817 remains the only binary neutron star merger detected through multimessenger emission. Its afterglow has been monitored for nearly a decade, offering an unprecedented opportunity to probe the properties of the outflow. The shallow decay of the very late-time afterglow challenges the prediction of a collimated structured jet. Motivated by recent general-relativistic magnetohydrodynamic simulations, we propose that the GW170817 afterglow is powered by a wobbling jet that drags a ring on the sky. This structure predicts a post-break decay rate shallower than that of a collimated jet, as o"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Through a Bayesian analysis of the multimessenger data, we find a ring-shaped jet is favored over a collimated jet at a significance level of 4.8σ. Our results imply a wobbling angle of ∼27°.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That a wobbling jet necessarily drags a ring-shaped structure whose post-break emission produces a shallower decay than a collimated jet, with no additional components required.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A ring-shaped wobbling jet explains the shallow late-time afterglow decay of GW170817 better than a collimated jet at 4.8 sigma significance, implying a ~27 degree wobble angle.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A wobbling jet that drags a ring on the sky explains the shallow late afterglow of GW170817 without extra components.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"7eb88d3a61cda707b58e2fa584c6efca653bd07dc0c5ad2f782103deaf418b05"},"source":{"id":"2605.13719","kind":"arxiv","version":1},"verdict":{"id":"5ffe2919-ae1c-4d30-b457-1b3615b5234c","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T17:40:08.514045Z","strongest_claim":"Through a Bayesian analysis of the multimessenger data, we find a ring-shaped jet is favored over a collimated jet at a significance level of 4.8σ. Our results imply a wobbling angle of ∼27°.","one_line_summary":"A ring-shaped wobbling jet explains the shallow late-time afterglow decay of GW170817 better than a collimated jet at 4.8 sigma significance, implying a ~27 degree wobble angle.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That a wobbling jet necessarily drags a ring-shaped structure whose post-break emission produces a shallower decay than a collimated jet, with no additional components required.","pith_extraction_headline":"A wobbling jet that drags a ring on the sky explains the shallow late afterglow of GW170817 without extra components."},"references":{"count":56,"sample":[{"doi":"","year":2017,"title":"GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral","work_id":"a19136e8-99c2-49be-b029-60af2e20c6ee","ref_index":1,"cited_arxiv_id":"1710.05832","is_internal_anchor":true},{"doi":"","year":2017,"title":"and others , Journal =","work_id":"f58cfd8e-a290-4b7c-b694-f252bed9dae9","ref_index":2,"cited_arxiv_id":"1710.05833","is_internal_anchor":true},{"doi":"","year":2017,"title":"Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A","work_id":"698d844c-7eca-45ec-8b87-a02243aaec15","ref_index":3,"cited_arxiv_id":"1710.05834","is_internal_anchor":true},{"doi":"","year":2017,"title":"The X-ray counterpart to the gravitational wave event GW 170817","work_id":"eaad92db-58de-4195-8ed0-f63515cf0a3b","ref_index":4,"cited_arxiv_id":"1710.05433","is_internal_anchor":true},{"doi":"","year":2018,"title":"A cocoon shock breakout as the origin of the $ \\gamma $-ray emission in GW170817","work_id":"002e39d8-a5f5-4e9c-9243-9bd85599dcbf","ref_index":5,"cited_arxiv_id":"1710.05896","is_internal_anchor":true}],"resolved_work":56,"snapshot_sha256":"5d414b6622060f16bf541067b0c501bec7cb200cb27fd4a3ee6ee02c71da391c","internal_anchors":26},"formal_canon":{"evidence_count":2,"snapshot_sha256":"e02c3cc94aee6300fcfd16e1ff4dfa7f8c965733592af896748682bfa5d3a246"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}