{"paper":{"title":"Determine the Lorentz factor and the viewing angle of GRB 170817A","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"(2) HUJI, (3) NJU), Bin Liao (1), Fa-Yin Wang (3) ((1) HUST, Fei-Fei Wang (1), Qingwen Wu (1), Reetanjali Moharana (2), Wei Chen (1), Wei-Hua Lei (1), Yuan-Chuan Zou (1)","submitted_at":"2017-10-20T07:25:59Z","abstract_excerpt":"GRB 170817A is a weak short gamma-ray burst (GRB) accompanied by the gravitational wave (GW) event GW170817. It is believed, that an off beaming relativistic jet, produces this weak GRB. Here we use the $E_{\\rm p,i}- E_{\\rm iso}$ and $\\Gamma - E_{\\rm iso}$ relations to determine the Lorentz factor $\\Gamma$ and the viewing angle from the edge of the jet $\\theta'_{\\rm obs}$ of GRB 170817A. Our result shows, $\\Gamma = 13.4 ^{+9.8}_{-5.5}$ and $\\theta'_{\\rm obs} = 4.3^{+1.8}_{-1.5} \\,^{\\circ}$. This corresponds to the on-axis $E_{\\rm p,i} = 415^{+361}_{-167}$ keV and $E_{\\rm iso} = (2.4^{+1.6}_{-1"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1710.07436","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":""},"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"}