Progenitors of Magnetars and Hyperaccreting Magnetized Disks and Central Engines of GRBs

1. Progenitors of Magnetars and Hyperaccreting Magnetized Disks andCentral Engines of GRBs 报告人： 谢 祎 导师： 张双南 中国科学院国家天文台

2. Gamma-ray bursts: the most violent explosions in the universe!！

3. SGR 1806-20

6. The Formation of a Magnetar • (i) Generated by a convective dynamo ; (Duncan & Thompson 1992) • (ii) Essentially of fossil origin ; (e.g. Ruderman 1972; Ferrario & Wickramasinghe 2006) • (iii) Evolved from some radio pulsars after many glitches . (Lin & Zhang 2004).

7. Duncan & Thompson 1992

9. Stage 1: the magnetic fields were magnified significantly in hyperaccreting process. 角动量守恒： 状态方程： 能量守恒方程：

10. 根据MRI理论盘上放大后的磁场分量有如下关系：根据MRI理论盘上放大后的磁场分量有如下关系： 同时与吸积率相关的粘滞系数及盘压有如下关系： Stage 2: magnetic fields inherited by central neutron star.

13. >5 ms:<~0.05 Msun/s <~0.074 Msun >~0.0001 Msun/s >~0.00015 Msun

14. Towards a Unified Model Magnetar • GRBs: typical ~0.1 Msun/s • SGRs & AXPs: ~0.0001 Msun/s --- ~0.05 Msun/s • Normal Radio Pulsars:<~0.0001 Msun/s • GRBs, always!

16. Thank you!