Transcript pptx
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 Baryon Loading G or r/r0 G* ~103 Paczynski, Goodman Meszaros & Rees Shemi & Piran MatterDominated Radiation-Dominated Photon-to-Baryon h*~103 h=E/Mc2 Baryon Loading G or r/r0 Compactness Non-thermal IS Synchro. Photosphere G* ~103 Beloborodov Vurm, Daigne Medvedev, Ryde, Lundman Original Paczynski Goodman Except Zhang & Yan 11, KI 10, Tchekhovskoy+ 10, McKinney 10, Gianinnos+ 07 (& others?) Photon-to-Baryon ~102 h*~103 h=E/Mc2 Fermi Revolution GeV g from GRBs GRB 090510 keV MeV Abdo+ 09 GeV Baryon Loading G or r/r0 Fermi limit IS Synchro. Photosphere Omodei Racusin Ghisellini BB Zhang Original Paczynski Goodman G* ~103 Photon-to-Baryon But, Hascoet+ 11 Zou+ 10, Aoi+ 10 h*~103 h=E/Mc2 Baryon Loading G or r/r0 Fermi limit IS Synchro. Photosphere G* ~103 Omodei Racusin Ghisellini BB Zhang Original Paczynski Goodman Fine Tuning? Photon-to-Baryon h*~103 h=E/Mc2 Internal Shock in RD? Time (t) Light path Gr ⇒ No Internal Shock r0 ~ ~ Causal 2 2cG0 r0 Space (r) Confinement G r G r , 1 r 1 External pressure or Magnetic 2 2 2 V r G r G T V 1 3 Tchekhovskoy Narayan adiabatic GT V const 4 Internal Shock in RD? Time (t) Light path Gr ⇒ No Internal Shock r0 ~ ~ Causal 2 2cG0 r0 Space (r) Internal Shock in RD! Time (t) Light path 1 G r , <1 2 r0 ~ ~ Causal 2 2cG0 r0 Space (r) Internal Shock in RD! Time (t) All rapid shells can catch-up like IS Light path 1 Gr , 0 2 r/G always increases (so trivial) 2 r0 ~ ~ Causal 2 2cG0 r0 Space (r) Poynting models 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 G Cocoon Confinement Gr , r Pressure balance at 1.Jet head 2.Cocoon-Star 3.Jet-Cocoon 1 * r n 4n ~ 14 ~1/2 for n=3 (Rad. env ⇒ Dissipative Aloy+ 00, Lazzati+ 09, Morsony+ 10, Mizuta+ 10 Cocoon Confinement Gr , r Pressure balance at 1.Jet head 2.Cocoon-Star 3.Jet-Cocoon 1 * r n 4n ~ 14 ~1/2 for n=3 (Rad. env ⇒ Dissipative Aloy+ 00, Lazzati+ 09, Morsony+ 10, Mizuta+ 10 Fast Cocoon just escaping from the jet head sideways at the breakout Gfc~Gj(tbreak)~10-30 ⇒ persist around the jet pfc~r-8/3 ⇒ Confine -4 pj~r Gr 2 ⇒ Internal ~ 3 Shock Shock ⇒ g acceleration ⇒ e± • • • • • Photons carries almost all the energy Budnik+ 10 Shock via Compton (g mediated shock) Fermi-like acceleration of photons Blandford & Payne 7 y-parameter can be of unity Appreciable energy can go to gg→e± • Outflow can keep e± tT~t’shock/t’dyn>1 Density or G electron/positron 3D Rela. MHD Turbulence Richtmyer-Meshkov turbulence Thompson 94 T. Inoue, Asano & KI 11 A small n is enough to drive turbulence Lorentz Factor If e± are kept by internal shocks out to e± photosphere =2/3 in the last eq. High Lorentz Factor c.f. KI(10) for baryonic case Extended g-Generation Radiation-Dom. Internal Shock Photosphere Shocks would continue beyond photosphere r t T 2 r12 ~ r1/ 3 G F ~GGrel2mec2 MeV GeV CTA ~20GeV-100TeV x10 Sensitivity ~1-2 min FOV~5-10 deg ~20 s slew (LST) ~2015 (?) ~150€ TeV g from GRB or not? O’Brien Granot S. Inoue Summary G or r/r0 Fermi limit IS Synchro. Photosphere G* ~103 Original Paczynski Goodman Fine Tuning? Photon-to-Baryon h*~103 h=E/Mc2 Summary G or r/r0 Fermi limit Unexplored IS Synchro. Original Photosphere Frontier?Paczynski Goodman RD Internal Shock via Confinement G* ~103 Photon-to-Baryon h*~103 h=E/Mc2 Implications • Lorentz factor: Cutoff probed by CTA • Non-thermal spectrum ~ Band • Extended g generation, deep inside gsphere • Early afterglow, High efficiency is possible • GeV lag ~ rphotosphere/cGfc2 • UHECR, neutrino • Magnetic field dissipation McKinney • Blandford-Znajek B Amplification & Decay behind shock f=1.8 T. Inoue, Asano & KI 11 Most Ancient Object GRB 090423 @ z~8.2 A massive star’s death just 600 Myr after the Big B First GRB Present Day Massive Star ~20M Abel+ 02 Bromm+ 02 Omukai+ 03 Yoshida+ 08 Pop III (Zero Metal) ~1001000M(!?) Komissarov & Barkov 10 Meszaros & Rees 10 Gigantic (x100) GRB @ z~10-30??? Massive Envelope R/c~103s > TGRB~10s ⇒ No GRB? Core Ohkubo+ 09 Heger+ 03 Suwa & KI 10 No mass loss via Envelope line driven wind Envelope Accretion Ý LM ⇒ vJet head • Energetic • Very long • Modest L Bright phase ⇒ Cocoon Suwa & KI 10 Analytic Expressions GRB jet can breakout the first star!