2001/06/18 by Jason Pruet, Neal Dalal · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Gamma-ray bursts and supernovae #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/340750
published as Astrophys.J. 573 (2002) 770 · 12 pages, 3 figures
arxiv created 2001/06/18 · openalex publication_date 2002/07/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Roughly half of the observed gamma-ray bursts (GRBs) may arise from the shocking of an ultrarelativistic shell of protons with the interstellar medium (ISM). Any neutrons originally present in the GRB fireball may, depending on the characteristics of the central engine, dynamically decouple as the fireball accelerates. This leads to outflow consisting of separate fast-proton and slow-neutron components. We derive detailed implications of neutron decoupling for the observed light curves of short bursts. In particular, we show that the collision of a neutron-decayed shell with a decelerating outer shell is expected to result in an observable second peak in the GRB light curve. There may also be substantial optical emission associated with such an event. Two peaked bursts arising from neutron decoupling will generally have an interpeak duration equal to the duration of the second peak. We also discuss interesting inferences about central-engine characteristics allowed by existing BATSE data and a consideration of neutron decoupling.