1. Gamma-ray Bursts and Particle Acceleration Katsuaki Asano (Tokyo Institute of Technology) S.Inoue （ NAOJ ）, P.Meszaros （ PSU ）

2. Physical Condition in a Shell R ΔR=R/Γ 2 Photons: Luminosity L In the comoving frame Energy Density: Magnetic Field:

3. Time Scales Let us consider a proton of 10 19 eV In the comoving frame, Dynamical Time Scale: Acceleration Time Scale: Cooling Time Scale:

4. How to find evidence of proton acceleration?

5. Neutrinos

6. Waxman and bahcall 1997, 1998 ｐ＋ γ→n+π ＋ π＋→μ＋ +νμπ＋→μ＋ +νμ μ ＋ →e ＋ + ν μ + ν e log E (eV ) l o g [ E N ( E ) ] 10 52 erg x 100  =500 R=5 10 14 cm  B =0.1  e at 1Gpc by 10 5 km 2 detector Kaon-decay Pion-decay Muon-decay  t=66 msec L=1.5 x 10 53 erg/s 1617181920 -4 -3 -2 -1 0 1 2 3 4 5 -4 -3 -2 -1 0 1 2 3 4 5 Next talk -> Murase Asano & Nagataki 2006

7. Photons See e.g. Meszaros 2006, Dermer & Atoyan 2006

8. GRB spectrum ???

9. To catch the sign of proton acceleration GLAST will be Launched May in this year. It will observe 10 MeV - 300 GeV photons.

10. TeV Photons HESS MAGIC CANGAROO-III

11. Proton Cascade ｐ＋ γ→n+π ＋ →p+π 0 Asano 2005

12. Distortion due to proton cascade Lepton distribution E Primary Electrons Pairs from Cascade f B =1.0 e-SY Our Monte Carlo Simulation Asano & Inoue 2007 Up=Ue f B =U B /Ue

13. Deviation due to Inv. Comp. f B =0.1 No sign of proton acceleration Asano & Inoue 2007 e-SY

14. Double break f B =1.0 Characteristic Spectrum due to Protons e-SY

15. Proton and muon synchrotron f B =30.0 e-SY

16. Proton acceleration efficiency We need 6-8 10 43 ergs/Mpc 3 /yr to explain UHECRs See e.g. Murase, Ioka, Nagataki, Nakamura 2008 We may need Up/Ue>20. If GRB rate is 0.05 Gpc -3 /yr, Up/Ue>100 We have assumed Up=Ue so far, but…

17. GRB rate

18. Much more protons are accelerated? Acceleration Larmor radius ∝ E Just behind the shock front

19. Much more protons Asano, Inoue, & Meszaros in prep. Proton=10 x Electron

20. Much more protons Proton=100 x Electron Photons from Proton cascade dominate. See also Asano & Takahara 2003

21. Very Hard GRB Kaneko et al. 2008 GLAST will find more such bursts ？

22. E sh -dependence

23. Up-dependence

24. Γ-dependence

25. Hypernova Very bright supernova Some associate GRBs Progenitors may be massive stars (WR type?). A stellar wind environment may exist around progenitors Ejecta from hypernovae may be sources of 10 17 -10 18 eV CRs. (Wang et al. 2007)

26. Hypernovae are Sources of 10 18 eV Cosmic Rays ？ 10 20 eV SNR ？ AGN? GRB? 銀河団 ? ？？ Wang et al. 2007

27. Particle Acceleration in Winds Faster, Energetically lower

28. Secondary Particles Asano & Meszaros 2008 @100Mpc ～ 4 days integration

29. Secondary Photons ～ 4 days integration

30. Regenerated Photons GRB Gamma-ray IR background photons e + e - CMB photons Inv. Comp. Razzaque et al. 2004

31. Summary GeV-TeV emissions due to protons in GRBs Too much protons change spectra drastically Secondary emission from hyeprnovae –X-ray due to cascade from muon decay –GeV emission from proton synchrotron –“Delayed” TeV emission