{"paper":{"title":"Evidence for X-ray Emission in Excess to the Jet Afterglow Decay 3.5 yrs After the Binary Neutron Star Merger GW 170817: A New Emission Component","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. Hajela, A. Kathirgamaraju, A. MacFadyen, A. McDowell, B. D. Metzger, B. Margalit, C. D. Kilpatrick, C. Guidorzi, D. Coppejans, D. Giannios, D. J. Matthews, D. Radice, E. Berger, F. S. Broekgaarden, G. Hosseinzadeh, G. Terreran, I. Heywood, J. C. Rastinejad, J. S. Bright, J. Zrake, K. D. Alexander, L. Sironi, M. Nicholl, O. Gottlieb, P. K. Blanchard, R. Barniol Duran, R. Chornock, R. Margutti, S. Bernuzzi, S. Gomez, T. Eftekhari, T. Laskar, V. A. Villar, V. Nedora, W. Fong, x. Xie, Y. Cendes","submitted_at":"2021-04-05T18:00:00Z","abstract_excerpt":"For the first $\\sim3$ years after the binary neutron star merger event GW 170817 the radio and X-ray radiation has been dominated by emission from a structured relativistic off-axis jet propagating into a low-density medium with n $< 0.01\\,\\rm{cm^{-3}}$. We report on observational evidence for an excess of X-ray emission at $\\delta t>900$ days after the merger. With $L_x\\approx5\\times 10^{38}\\,\\rm{erg\\,s^{-1}}$ at 1234 days, the recently detected X-ray emission represents a $\\ge 3.2\\,\\sigma$ (Gaussian equivalent) deviation from the universal post jet-break model that best fits the multi-wavele"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2104.02070","kind":"arxiv","version":2},"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/2104.02070/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"}