Unstable e±Photospheres and GRB Spectral Relations
We propose an emission mechanism of prompt gamma-ray bursts(GRBs)that can reproduce the observed nonthermal spectra with high radiative efficiencies,>50％．We show that,if e±pairs outnumber protons,a radiation-dominatedphotosphere becomes unstable to the phase separation between pairs and proton clumps．Pairs ale continuously shock heatedby proton clumps,scattering the thermal photons into the observed broken powe-law shape．If GRBs come from pairphotospheres,pair annihilation lines are predicted above continua．A closure relation exists between the pair annihilationline and the pair creation cutoif,wbich enables GLAST to test the model and also constrain physical quantities such as theLorentz factor．optical depth and pair-to-baryon ratio,only from observables,even without either line or cutofr．We also discussthe Suzaku/WAM results of the time-resolved Ep-L(Yonetoku)relation and the Ep-L relation for short GRBs．We suggest thatthe short GRBs could arise from the self-created photospheres．We also deal with the hypernova and GRB remnants emittingTeV gamma-rays via the decay of accelerated radioactive isotopes,such as 56 Co conveyed by the GRBjets．
gamma rays bursts-gamma rays theory-radiation mechanism non-thermal
Kunihito Ioka Kohta Murase Kenji Toma Shigehiro Nagataki Takashi Nakamura Peter Meszaros
Cosmophysics Group,IPNS,KEK(High Energy Accelerator Research Organization) and the Graduate Univers YITP,Kyoto University,Oiwake-cho,Kitashirakawa,Sakyo-ku,Kyoto,606-8502,Japan Center for Particle Astrophysics,Pennsylvania State University,University Park,PA 16802 Department of Physics,Kyoto University,Kyoto 606-8502,Japan
国际会议
2008 NanJing Gamma-Ray Burst Conference(2008年伽马暴国际研讨会)
南京
英文
189-194
2008-06-23（万方平台首次上网日期，不代表论文的发表时间）