{"paper":{"title":"Magnetohydrodynamic Simulations of Gamma-Ray Burst Jets: Beyond the Progenitor Star","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.HE","authors_text":"(2) Department of Physics, Alexander Tchekhovskoy (1), Cosmology, Jonathan C. McKinney (2) ((1) Harvard-CfA, Kavli Institute for Particle Astrophysics, Ramesh Narayan (1), Stanford University)","submitted_at":"2009-08-31T20:16:00Z","abstract_excerpt":"Achromatic breaks in afterglow light curves of gamma-ray bursts (GRBs) arise naturally if the product of the jet's Lorentz factor \\gamma and opening angle \\Theta_j satisfies (\\gamma \\Theta_j) >> 1 at the onset of the afterglow phase, i.e., soon after the conclusion of the prompt emission.  Magnetohydrodynamic (MHD) simulations of collimated GRB jets generally give (\\gamma \\Theta_j) <~ 1, suggesting that MHD models may be inconsistent with jet breaks.  We work within the collapsar paradigm and use axisymmetric relativistic MHD simulations to explore the effect of a finite stellar envelope on th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0909.0011","kind":"arxiv","version":3},"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"}