Joint BAT and XRT Data Analysis for Gamma-Ray Bursts

1. Joint BAT and XRT Data Analysis for Gamma-Ray Bursts Enwei Liang Co-authors: Youdong Hu, Fangkun Peng, Bing Zhang, Xiang-Yu Wang, Xuefeng Wu GXU-NAOC Center for Astrophysics & Space Sciences IHEP, 2014- 03-22

2. Outlines • Internal Energy Dissipation of Gamma-Ray Bursts Observed with Swift: • Precursors,Prompt Gamma-rays,Extended emission, Late X-ray Flares • Joint Spectral Analysis for X-Ray Flares with BAT and XRT data: • Possible Thermal Emission over the Band function component

3. Outlines • Internal Energy Dissipation of Gamma-Ray Bursts Observed with Swift: • Precursors,Prompt Gamma-rays,Extended emission,Late X-ray Flares • Joint Spectral Analysis for X-Ray Flares with BAT and XRT data: • Possible Thermal Emission in the Flares

4. 1.GRB precursor Precursor BAT 060124 121217 110709B Double trigger ? XRT 121217 In the second episode: the X-ray emission comes much earlier than the Gmma-rays Romano et al. 2006; Zhang et al. 2012; Hu et al. 2013

5. 1.GRB precursor:the tip of an iceberg? • What may happen prior the gamma-ray trigger in a lower energy band? 121217 06124 110709B ? 121217 In the second episode: the X-ray emission comes much earlier than the Gmma-rays Romano et al. 2006; Zhang et al. 2012; Hu et al. 2014

6. Searching for emission in prior the BAT trigger for Swift GRBs Lightcurve structure analysis: Beyasian block method. Increasing the time bin of the lightcurves to search for the low S/N signal. S/N> 3 sigma Bin size Hu, Liang et al. 2014, ApJ, submitted

7. Trigger and Non-Trigger Precursors Hu, Liang et al. 2014, ApJ, submitted

8. Trigger and Non-Trigger Precursors Current BAT sample  Emission in prior to the BAT trigger was detected for ~ 10% of GRBs (S/N> 3 sigma). Hu, Liang et al. 2014, ApJ, submitted

9. Precursors

11. Spectral properties No significant difference is found among the photon indices of well-separated precursors, flickering prior the BAT trigger, and the main burst! Well-separated precursors prior flickering Hu, Liang et al. 2014, ApJ, submitted

12. Statistics for the precursors Prefer to be observed in long-type GRBs Detection ratio :~ 10% Ph. Index: Precursors vs Main episodes

13. 2. Extended Emission Tails

14. Statistics for the EE tails Prefer to be observed in GRB 060614-liked GRBs Ph. Index: Precursors vs Main episodes

15. An explanation of the EE tails Liu, Liang et al. 2012, ApJ

16. 3. Quiescent BAT phase and X-ray flares

17. Types of Joint BAT_XRT LCs Qin, Liang et al. 2013, ApJ

18. X-ray Flares

19. Energy Dependence of the duration of the internal process Qin et al. 2013, ApJ

20. Gamma-ray Bursts the tip of an iceberg of Explosions from Collapsars and Mergers?

21. Outlines • Internal Energy Dissipation of Gamma-Ray Bursts Observed with Swift: • Precursors,Prompt Gamma-rays,Extended emission,Late X-ray Flares • Joint Spectral Analysis for X-Ray Flares with BAT and XRT data: • Possible Thermal Emission in the Flares

22. Sample

23. Strategy of Our Spectral Fit • Single power-law fit • add black body component • PL—Band function Peng et al. 2014, in preparation

24. Powper-Law Fits Peng et al. 2014, in preparation

25. Peng et al. 2014, in preparation

26. Power-Law+BB Fits Peng et al. 2014, in preparation

27. Peng et al. 2014, in preparation

28. Band function fits: Peng et al. 2014, in preparation

30. Efficiency of Photosphere GRB 090902B GRB 081212 GRBs in our sample High low efficiency of the photosphere?

31. L-Ep relations: Band vs BB Peng et al. 2014, in preparation

32. Lorntz Factors of the fireball derived from the BB component Peng et al. 2014, in preparation

33. 基于GPD技术的大视场宽波段X射线光电偏振仪

34. Gas Pixel Detector （GPD） • 像素读出，二维成像 • 能同时获得光子图像、偏振、能量、方位等信息 • 具备宽视场探测能力 • 探测效率相对低 • 电子学通道数多 昨天刘宏邦博士去航天二院谈了偏振探测用THEMG制作的相关事项，确定按原定的参数 制作一批THEGM，最早下周能的到样片！ Costa et al. 2001 Bellazzini et al. 2006, 2007, 2013

35. Thanks!