Author/Authors :
T. Toizumi، نويسنده , , T. Enomoto، نويسنده , , Y. Yatsu، نويسنده , , T. Nakamori، نويسنده , , N. Kawai، نويسنده , , K. Ishizaka، نويسنده , , A. Muta، نويسنده , , H. Morishita، نويسنده , , K. Akiyama، نويسنده , , N. Kisa، نويسنده , , S. Inagawa، نويسنده , , M. Kawakubo، نويسنده , , J. Nishida، نويسنده , , S. Mizunuma، نويسنده , , S. Matsunaga، نويسنده , , J. Kataoka، نويسنده ,
Abstract :
Tsubame is a university-built small satellite mission to measure polarization of hard X-ray photons (30–200 keV) from gamma-ray bursts (GRB) using azimuthal angle anisotropy of Compton-scattered photons. Polarimetry in the hard X-ray and soft gamma-ray band should play a crucial role in understanding of high energy emission mechanisms, the distribution of magnetic fields and radiation fields of gamma-ray bursts. Tsubame has two instruments: the Wide-field Bust Monitor (WBM) and the Hard X-ray Compton Polarimeter (HXCP). The WBM detects a burst and determines on board the direction of the burst occurrence with an accuracy of 10°. The spacecraft is then slewed to point the GRB within 15 s from the WBM trigger using the Control Moment Gyro (CMG), a high speed attitude control device. HXCP will measure the polarized X-ray photons from the GRB while the spacecraft spins slowly around the bore sight. In this paper, we present an overview of the Tsubame mission, the results of a test experiment for HXCP using a polarized hard X-ray beam, and its comparison with a Monte Carlo simulation.
