1. Gamma-Ray Bursts from Radiation-Dominated Jet? Kunihito Ioka (KEK) T. Inoue, Asano & KI, arXiv: 1011.6350 KI, arXiv: 1006.3073 Suwa & KI, arXiv: 1009.6001 KI+, in preparation (arXiv: 1103.5746) Sorry for changing the title to a preliminary study Comments welcome

2. Baryon Loading  or r/r 0  =E/Mc 2  * ~10 3  * ~10 3 Photon-to-Baryon Radiation-Dominated Matter- Dominated Paczynski, Goodman Meszaros & Rees Shemi & Piran

3. Baryon Loading  or r/r 0  =E/Mc 2  * ~10 3  * ~10 3 IS Synchro. Photosphere Original Paczynski Goodman Photon-to-Baryon Compactness Non-thermal Except Zhang & Yan 11, KI 10, Tchekhovskoy+ 10, McKinney 10, Gianinnos+ 07 (& others?) Beloborodov Vurm, Daigne Medvedev, Ryde, Lundman ~10 2

4. Fermi Revolution GeV  from GRBs GRB 090510 Abdo+ 09 GeV MeV keV

5. Baryon Loading  or r/r 0  =E/Mc 2  * ~10 3  * ~10 3 IS Synchro. Photosphere Fermi limit Photon-to-Baryon Original Paczynski Goodman But, Hascoet+ 11 Zou+ 10, Aoi+ 10 Omodei Racusin Ghisellini BB Zhang

6. Baryon Loading  or r/r 0  =E/Mc 2  * ~10 3  * ~10 3 IS Synchro. Photosphere Fermi limit Photon-to-Baryon Original Paczynski Goodman Fine Tuning? Omodei Racusin Ghisellini BB Zhang

7. Internal Shock in RD? Time (t) Space (r) r0r0 Light path ⇒ No Internal Shock Rapid Shell Slow Shell

8. Confinement External pressure or Magnetic Tchekhovskoy Narayan

9. Internal Shock in RD? Time (t) Space (r) r0r0 Light path ⇒ No Internal Shock

10. Internal Shock in RD! Time (t) Space (r) r0r0 Light path

11. Internal Shock in RD! Time (t) Space (r) r0r0 Light path All rapid shells can catch-up like IS r/  2 always increases (so trivial) Poynting models

12. Internal Shock of RD Flow 1. Internal Shock is possible for RD outflow 2. Up to a large radius 3. Repeatedly ⇒ Can keep e ± up to high 

13. Cocoon Confinement Pressure balance at 1.Jet head 2.Cocoon-Star 3.Jet-Cocoon ~1/2 for n=3 (Rad. env.) ⇒ Dissipative Aloy+ 00, Lazzati+ 09, Morsony+ 10, Mizuta+ 10

14. Cocoon Confinement Pressure balance at 1.Jet head 2.Cocoon-Star 3.Jet-Cocoon ~1/2 for n=3 (Rad. env.) ⇒ Dissipative Aloy+ 00, Lazzati+ 09, Morsony+ 10, Mizuta+ 10

15. Fast Cocoon just escaping from the jet head sideways at the breakout  fc ~  j (t break )~10-30 p fc ~r -8/3 p j ~r -4 ⇒ Confine ⇒ persist around the jet ⇒ Internal Shock

16. Shock ⇒  acceleration ⇒ e ± Photons carries almost all the energy Shock via Compton (  mediated shock) Fermi-like acceleration of photons y-parameter can be of unity Appreciable energy can go to  →e ± Outflow can keep e ±  T ~  t’ shock /t’ dyn >1 electron/positron Density or  Blandford & Payne 78 Budnik+ 10

17. Turbulence T. Inoue, Asano & KI 11 A small  n is enough to drive turbulence Richtmyer-Meshkov turbulence 3D Rela. MHD Thompson 94

18. Lorentz Factor =2/3 in the last eq. If e ± are kept by internal shocks out to e ± photosphere High Lorentz Factor c.f. KI(10) for baryonic case

19. Extended  -Generation Photo- sphere Radiation-Dom. Internal Shock MeV GeV ~  rel 2 m e c 2 Shocks would continue beyond photosphere

20. CTA ~20GeV-100TeV x10 Sensitivity  ~1-2 min FOV~5-10 deg ~20 s slew (LST) ~2015 (?) ~150€ TeV  from GRB or not? O’Brien Granot S. Inoue

21. Summary  or r/r 0  =E/Mc 2  * ~10 3  * ~10 3 IS Synchro. Photosphere Fermi limit Photon-to-Baryon Original Paczynski Goodman Fine Tuning?

22. Summary Original Paczynski Goodman  or r/r 0  =E/Mc 2  * ~10 3  * ~10 3 IS Synchro. Photosphere Fermi limit Photon-to-Baryon UnexploredFrontier? RD Internal Shock via Confinement UnexploredFrontier?

23. Implications Lorentz factor: Cutoff probed by CTA Non-thermal spectrum ~ Band Extended  generation, deep inside  - sphere Early afterglow, High efficiency is possible GeV lag ~ r photosphere /c  fc 2 UHECR, neutrino Magnetic field dissipation Blandford-Znajek McKinney

24. T. Inoue, Asano & KI 11 f=1.8 B Amplification & Decay behind shock

25. Most Ancient Object A massive star’s death just 600 Myr after the Big Bang GRB 090423 @ z~8.2

27. First GRB Pop III (Zero Metal) ~100- 1000M  (!?) Pop III (Zero Metal) ~100- 1000M  (!?) Present Day Massive Star ~20M  Abel+ 02 Bromm+ 02 Omukai+ 03 Yoshida+ 08 Gigantic (x100) GRB @ z~10-30??? Komissarov & Barkov 10 Meszaros & Rees 10

28. Massive Envelope Ohkubo+ 09 Heger+ 03 Suwa & KI 10 No mass loss via line driven wind R/c~10 3 s > T GRB ~10s ⇒ No GRB? Core Envelope

29. Envelope Accretion Suwa & KI 10 Energetic Very long Modest L Bright phase ⇒ Cocoon ⇒ v Jet head

30. Analytic Expressions

31. GRB jet can breakout the first star!