广西大学天体物理学科介绍

TightLiso-Ep-Γ0RelationofLongGamma-RayBurstsEnweiLiangGuangxiUniversity,ChinaIAUS324:NewFrontiersinBHAstrophys.2016.9.12-9.16,LjubljanaSelovenia2GeneralPictureofGamma-RayBurstsV≥0.9999cGRBsandtheirafterglowsareproducedfromextremelyrelativisticjetspoweredbythecentralengine.EstimatingtheInitialΓ0ofGRBjetsWiththefireballdecelerationtime(e.g.,Sari&Piran1999)Withthecompactnessargument:(e.g.,Lithwick&Sari2001)Withthephotosphereradiation:(e.g.Zou+2015)Liang+2010Tang+2014Peng+2014OpticalandX-rayafterglowCartoonLightcurvesZhangetal.2006,ApJ;Li,Liangetal.2012,ApJOpticalEmissioncomponentsX-rayEmissioncomponentsRelationbetweenafterglowonsetandpromptgamma-raysLiangetal.2010,ApJOpticalafterglowonsetisdetectedfor1/3ofGRBsOnsetpeakluminosityiscorrelatedwithpromptgamma-rayluminosity.Eiso(orLiso)-Γ0RelationAtightcorrelationbetweentheEisoandtheLorentzfactorofGRBfireballLiangetal.2010，2013,ApJ;LVetal.2012,ApJLEiso(orLiso)-EpRelationTheserelationswasfoundwithGRBsdetectedwithBeppoSAXandalsoconfirmedwithSwift/BATandFermi/GBMGRBs.Amatietal.2012,IJMPDYonetokuetal.2004,ApJLuetal.2012,ApJIsthelargeintrinsicdispersionofpaircorrelationsduetomissingofthethirdpart?Relationamongthethreeparameters?Eiso(orLiso)-Epvs.Eiso(orLiso)-Γ0RelationAmatietal.2012,IJMPDLiangetal.2010,ApJ9AtightLiso-Ep,z-Γ0relationLiang+2015,ApJGRB060218:Γ0~2.3（Soderberg+2006）10AtightLiso-Ep,z-Γ0relationLiang+2015,ApJGRB060218:Γ0~2.3（Soderberg+2006）DoublecheckwithGRBswhoseΓ0arederivedfromthespectralcutoffenergyobservedwithFermi/LAT.11Dai,Liang,&Xu2004,ApJL；Liang&Zhang2005,ApJLiso-Ep,z-Γ0asanewGRBcosmologyruler?Ejet-Eprelation(Ghirlanda+2004)Eiso-Ep-tjetrelation(Liang&Zhang2005)12Liang+2015;Xin+2016Liso-Ep,z-Γ0asanewGRBcosmologyruler?Advantages:Atighterrelationthanpreviousones.Issues:NeedingtobeconfirmedwithLL-GRBs(moderaterelativisticjets?)NeedingtogeometriccorrectiontoLisoIdentifyingthecosmicevolutionofjetluminosity.？3.OurOn-GoingObservationalProjectR=21iPTFR=16GWACR=13Mini-GWACGRBsOpticalTels-400s-200s0100s5m1h1dFluxmagnitudeR=1960/80cmGRBtriggerFollow-upHu+2014Singer+2012OurCurrentOpticalMonitoringProjectIdentificationandearlyphotometrySpectrum、redshiftLatephotometry30s10mhoursGWAC/GRBalert60/80cmTelescope2mtelescopetriggerExamplesofOurMonitoringResultsMini-GWACupperlimit:M=13.2B,V,R,Iobservationswithour60/80cmtelescopesinXinglongObservatory.GRB160131ALiang+2016,inprep.Xin+2016,ApJ,submittedGRB140629Zhong+2016,ApJ,inpressHuang+2016,ApJ,inpressXin+2016a,ApJ21SummaryMeasuringthejetinitialLorentzfactorsofGRBswiththefireballdecelerationtimeobservedintheopticalbandrangefrom~100to1000.TheLorentzfactorsarecorrelatedwithLiso(orEiso),andatightercorrelationisfoundbyaddingEp.TheLiso-Ep,z-Γ0maybeapromisingGRBcosmologyruler,butissuesarestillthere.Ournewobservationalprojectisgoingonforpushingthecosmologyuseofthisrelation.Thanks!