{"paper":{"title":"The Bright and the Slow -- GRBs 100724B \\& 160509A with high-energy cutoffs at $\\lesssim100\\;$MeV","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"F. Longo, G. Vianello, J. Cohen-Tanugi, J. Granot, N. Omodei, R. Gill","submitted_at":"2017-06-05T18:12:49Z","abstract_excerpt":"We analyze the prompt emission of GRB 100724B and GRB 160509A, two of the brightest Gamma-Ray Bursts (GRBs) observed by Fermi at $\\lesssim{\\rm MeV}$ energies but surprisingly faint at $\\gtrsim100\\;$MeV energies. Time-resolved spectroscopy reveals a sharp high-energy cutoff at energies $E_c\\sim20-60\\;$MeV for GRB~100724B and $E_c\\sim80-150\\;$MeV for GRB~160509A. We first characterize phenomenologically the cutoff and its time evolution. We then fit the data to two models where the high-energy cutoff arises from intrinsic opacity to pair production within the source ($\\tau_{\\gamma\\gamma}$): (i) "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1706.01481","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"}