An analysis of <i>Chandra</i> Deep follow-up gamma-ray bursts

Bin-Bin Zhang, Hendrik Van Eerten, David N. Burrows, Geoffrey Scott Ryan, Philip A. Evans, Judith L. Racusin, Eleanora Troja, Andrew MacFadyen

OAI: oai:purehost.bath.ac.uk:publications/39c1d1e2-8848-4ce7-a133-6170d6bc4341 • DOI: https://doi.org/10.1088/0004-637X/806/1/15

We present a sample of 27 gamma-ray bursts (GRBs) with detailed Swift light curves supplemented by late-time Chandra observations. To answer the missing jet-break problem in general, we develop a numerical-simulation-based model that can be directly fit to the data using Monte Carlo methods. Our numerical model takes into account all the factors that can shape a jet break: (i) lateral expansion, (ii) edge effects, and (iii) off-axis effects. Our results provide improved fits to the light curves and constraints on physical parameters. More importantly, our results suggest that off-axis effects are important and must be included in interpretations of GRB jet breaks.

gamma-ray burst: general methods: numerical