@inproceedings{041cb06a2e1b41eeaee55ca9e54c3828,
title = "Study of emission mechanism of GRBs probed by the gamma-ray polarization with IKAROS-GAP",
abstract = "We report a polarization measurement in prompt γ-ray emission of GRB 100826A with the Gamma-Ray Burst Polarimeter (GAP) aboard the small solar power sail demonstrator IKAROS. We detected a firm change of polarization angle (PA) during the prompt emission with 99.9% (3.5 σ) confidence level, and an average polarization degree (II) of 27 ± 11% with 99.4% (2.9 σ) confidence level. Here the quoted errors are given at 1 σ confidence level for two parameters of interest. Non-axisymmetric (e.g., patchy) structures of the magnetic fields and/or brightness inside the relativistic jet are therefore required within the observable angular scale of ∼ σ -1. Our observation strongly indicates that the polarization measurement is a powerful tool to constrain the GRB production mechanism, and more theoretical works are needed to discuss the data in more details.",
keywords = "Gamma-Ray Bursts, emission mechanism, polarization",
author = "Daisuke Yonetoku and Toshio Murakami and Tomonori Sakashita and Yoshiyuki Morihara and Shuichi Gunji and Tatehiro Mihara and Kenji Toma",
year = "2011",
month = apr,
doi = "10.1017/S174392131201366X",
language = "English",
isbn = "9781107019799",
series = "Proceedings of the International Astronomical Union",
number = "S279",
pages = "425--426",
editor = "{San Antonio}, {Peter W. A.} and Nobuyuki Kawai and Elena Pian",
booktitle = "Death of Massive Stars",
edition = "S279",
}