Unveiling Emission Mechanism of Gamma-Ray Bursts from the Central Engine

在这个项目中，我们开发了我们的广义相对论MHD代码，并将其应用于伽马射线暴（GRB）射流形成的数值模拟。我们发现，旋转速度越快的黑洞可以驱动更强的伽马射线暴喷流。到目前为止，世界上只有两个小组成功地进行了这种模拟。我们还对相对论grb喷流的传播进行了数值模拟。通过估算GRB喷流的光球辐射，我们成功地解释了GRB中伽马射线的光度和能量之间的现象关系。此外，我们对伽马射线在grb喷流中的传播进行了蒙特卡罗模拟。我们成功地解释了grb的典型光谱，以及最近由日本卫星IKAROS观测到的大偏振。

For this project, we have developed our General Relativistic MHD code and applied it for numerical simulations of formation of Gamma-Ray Burst (GRB) jets. We found that more rapidly rotating black holes can drive stronger GRB jets. Up to now, only two groups in the world have succeeded to perform such simulations. We also did numerical simulations on propagation of relativistic GRB-Jets. We succeeded to explain the phenominological relation between Luminosity and Energy of Gamma-rays in GRBs by estimating the photospheric emission from the photosphere of GRB jets. Further, we did Monte-Carlo simulations for propagation of gamma-rays in GRB-jets. We succeeded to explain the typical spectrum of GRBs as well as large polarization that was observed recently by a Japanese satellite, IKAROS.