天体物理学科介绍课件.ppt

1、Tight Liso-Ep-0 Relation of Long Gamma-Ray BurstsEnwei LiangEnwei Liang Guangxi University,ChinaIAUS 324:New Frontiers in BH Astrophys.2016.9.12-9.16,Ljubljana Selovenia2General Picture of Gamma-Ray Bursts V 0.9999cGRBs and their afterglows are produced from extremely relativistic jetspowered by the

2、 central engine.Estimating the Initial 0 of GRB jets nWith the fireball deceleration time(e.g.,Sari&Piran 1999)nWith the compactness argument:(e.g.,Lithwick&Sari 2001)nWith the photosphere radiation:(e.g.Zou+2015)Liang+2010Tang+2014Peng+2014Optical and X-ray afterglow Cartoon LightcurvesZhang et al.

3、2006,ApJ;Li,Liang et al.2012,ApJOptical Emission componentsX-ray Emission componentsRelation between afterglow onset and prompt gamma-raysLiang et al.2010,ApJl Optical afterglow onset is detected for 1/3 of GRBsl Onset peak luminosity is correlated with prompt gamma-ray luminosity.Eiso(or Liso)-0 Re

4、lationA tight correlation between the Eiso and the Lorentz factor of GRB fireball Liang et al.2010，2013,ApJ;LV et al.2012,ApJLEiso(or Liso)-Ep RelationThese relations was found with GRBs detected with BeppoSAX and also confirmed with Swift/BAT and Fermi/GBM GRBs.Amati et al.2012,IJMPDYonetoku et al.

5、2004,ApJLu et al.2012,ApJnIs the large intrinsic dispersion of pair correlations due to missing of the third part?nRelation among the three parameters?Eiso(or Liso)-Ep vs.Eiso(or Liso)-0 RelationAmati et al.2012,IJMPDLiang et al.2010,ApJ9A tight Liso-Ep,z-0 relationLiang+2015,ApJGRB 060218:0 2.3（Sod

6、erberg+2006）10A tight Liso-Ep,z-0 relationLiang+2015,ApJGRB 060218:0 2.3（Soderberg+2006）Double check with GRBs whose 0 are derived from the spectral cutoff energy observed with Fermi/LAT.11Dai,Liang,&Xu 2004,ApJL；Liang&Zhang 2005,ApJLiso-Ep,z-0 as a new GRB cosmology ruler?nEjet-Ep relation(Ghirland

7、a+2004)nEiso-Ep-tjet relation(Liang&Zhang 2005)12Liang+2015;Xin+2016Liso-Ep,z-0 as a new GRB cosmology ruler?nAdvantages:qA tighter relation than previous ones.nIssues:qNeeding to be confirmed with LL-GRBs(moderate relativistic jets?)qNeeding to geometric correction to LisoqIdentifying the cosmic ev

8、olution of jet luminosity.n？3.Our On-Going Observational ProjectR=21iPTFR=16 GWACR=13 Mini-GWAC GRBsOptical Tels-400s -200s 0 100s 5m 1h 1dFluxFlux magnitudemagnitudeR=19 60/80cmGRB trigger Follow-upHu+2014 Singer+2012Our Current Optical Monitoring ProjectIdentification and early photometry Spectrum

9、、redshiftLate photometry30s10m10mhoursGWAC/GRB alert 60/80cm Telescope2m telescopetriggerExamples of Our Monitoring ResultsMini-GWAC upper limit:M=13.2 B,V,R,I observations with our 60/80 cm telescopes in Xinglong Observatory.GRB 160131ALiang+2016,in prep.Xin+2016,ApJ,submittedGRB 140629Zhong+2016,A

10、pJ,in pressHuang+2016,ApJ,in pressXin+2016a,ApJ21Summary lMeasuring the jet initial Lorentz factors of GRBs with the fireball deceleration time observed in the optical band range from 100 to 1000.lThe Lorentz factors are correlated with Liso(or Eiso),and a tighter correlation is found by adding Ep.lThe Liso-Ep,z-0 may be a promising GRB cosmology ruler,but issues are still there.lOur new observational project is going on for pushing the cosmology use of this relation.Thanks!