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Simulation Analysis of the Selection Effects on the Observed Redshift Dependence of GRB Jet Opening Angles. 报告者:魏俊杰 ( 硕士生 ) 指导老师 : 陆睿静(副教授)、梁恩维(教授). 广西大学 - 国家天文台 天体物理与空间科学中心 2011-08-23 厦门. 1.1 Jet break times and Jet opening angles. 1 、 Introduction.
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Simulation Analysis of the Selection Effects on the ObservedRedshift Dependence of GRB Jet Opening Angles 报告者:魏俊杰(硕士生) 指导老师 : 陆睿静(副教授)、梁恩维(教授) 广西大学-国家天文台 天体物理与空间科学中心 2011-08-23 厦门
1.1 Jet break times and Jet opening angles 1、Introduction Jet break would happen when the bulk Lorentz factor of the outflow (Γ) slows down to 𝑗 where 𝜃𝑗 is the half opening angle of the jet (Rhoads 1997, Sari et al. 1999, Frail et al. 2001)
1.2 The observed redshift dependences of jet opening angles Wei et al. 2003 The jet opening angle for high-z bursts should be much smaller than for low-z bursts.
1.3 Are there any intrinsic cosmological evolution features of GRBs exist? (Yonetoku et al. 2005; Lloyd-Ronning, Fryer & Ramirez-Ruiz 2002; Firmanietal.2004;Kocevski&Liang2006; Salvaterraetal.2008,2009) • Some authors have claimed that the GRB Jet opening angles may evolve with redshift • It was also proposed that GRB luminosity may experience evolution Are there any intrinsic cosmological evolution features of GRBs exist ?
2、Our data Uniform jet models
3、Simulation Analysis for the Instrumental Selection Effects 3.1 Models Rowan-Robinson 1999; Langer & Norman et al.2006; Matsubayashi et al. 2005; Lin et al. 2004; Qin et al. 2010.
3.2 Reference Sample for Constraining Model Parameters • We compare our simulated results to the observational data via: logN-logP L-distribution Z-distribution PKS(P,L,z)= PKS(P)* PKS(L)* PKS(z)
4、Simulation Results : log-normal distribution function : log-normal distribution function
5、Discussion : log-normal distribution function : power-law distribution function
6、Conclusions • Assuming that the intrinsic distributions of both 𝐿and 𝜃 are Gaussian, we have shown that the observed 𝜃dependence on redshift can be interpreted with the instrumental selection effects. • The same result of the case that the intrinsic distributions of are Gaussian and are power-law distributions. Thanks for your attention!