Kunihito Ioka (KEK)

1.  Γ>103 is possible 2.  Internal shock synchro. ⇒ keV-GeV-TeV γ

3.  3-D relativistic MHD simulation (Movie only)

High Lorentz Factor Fireballs for �

High-Energy GRB Emission

KI, arXiv:1006.3073, accepted in Prog. Theo. Phys.

T. Inoue, Asano & KI, in preparation

Fermi Revolution GeV γ from GRBs GRB 090510

Abdo+ 09

GeV MeV keV

High Lorentz Factor?

  γγ→e+e- (εth~MeV) –  R~cΔt ⇒ τ~σTNγ/4πR2≫1 (γ-ray cannot escape)

  Relativistic –  R~Γ2cΔt –  Blueshift –  τ~Γ2β-2~Γ-6

  Γ>103! v>0.999999×c

Γmin

Redshift But see also Li 08, Granot+08, Bosnjak+09, Aoi+KI 10, Zou+10

Conventional Γmax

  Fireball expands by radiation pressure   In principle, Γmax ~ Energy / Mass   Mass↓Γmax↑… However,

⇒ Transparent before Γ~Γmax

Paczynski 86 Goodman 86 Shemi & Piran 90 Meszaros & Rees

!max =!

L!T

4"mpc3r0

"1/4

! 103L1/453 r!1/4

0,7

Matter

Radiation escapes

Nonradiative Pressure

Radiation Pressure ~ Collisionless Pressure of Relativistic Particles

~

Magnetic Field

Not escape ⇒ Γmax=Energy/Mass can be attained

e, p

KI 10

γ

p

Radiation to Collisionless

r=r0

Center

Collisional ⇒ Radiation

Dominant

Effective Proton Thermalization

Optically Thin

Matter (Proton)

Eγ>Erela_p

Radiation to Collisionless

r=r0

Center Effective Proton Thermalization

Optically Thin

Eγ≈Erela_p

Collisionless shocks via Stellar matter

entrainment or Internal shock

below photopshere

Two Body Model

€

ErΓr + Mc 2 = ΓmMc2 + Em( )Γm

Er Γr2 −1 = ΓmMc

2 + Em( ) Γm2 −1

Energy

Momentum

€

⇒Γm ~ErΓr2Mc 2

∝L1 2

€

Er

Γr< Mc 2 < ErΓr

€

Em ~ ΓmMc2 : Radiation ~ Collisionless motion

Collisionless Radiation

2 eqs. for 2 unknowns

∝r-4 ∝r-4

Fireball

Er Γr

M Em Γm

Radiation Dominated

Fireball

Dissipated Fireball

Γmax of Dissipated Fireball

Γmax~106!

KI 10 Baryon-Less Baryon-Rich

>Γconv~103

Collsionless Bulk-

Acceleration

(To be opaque)

Photosphere-Internal-External Shock Model

Photo- sphere

Internal Shock

External Shock

€

νFν

€

νkeV MeV GeV

e.g., Toma, Wu & Meszaros Kumar & Barniol Duran 09 Ghisellini+09, Wang+09,KI 10 Zou+ 09, Ryde & Pe’er 09

Variable Long-lived Eγ~E/2

High Γ Internal Shock

KI 10

GeV γ: Simple IS synchro. emission

TeV GeV keV

CTA   ~20GeV-100TeV   x10 Sensitivity   Δθ~1-2 min   FOV~5-10 deg   ~20 s slew (LST)   ~2015 (?)   ~150€

TeV γ from GRB or not?

Poster 13.05 Jun Kakuwa

Photosphere-Internal-External Shock Model

Photo- sphere

Internal Shock

External Shock

€

νFν

€

νkeV MeV GeV

e.g., Toma, Wu & Meszaros Kumar & Barniol Duran 09 Ghisellini+09, Wang+09,KI 10 Zou+ 09, Ryde & Pe’er 09

Variable Long-lived Eγ~E/2

L∝T2

€

L = 4πr02caT0

4

Epeak ~ T0

L∝T4

Yonetoku+KI 03 Amati 02

Epeak-Luminosity Relation

Stefan- Boltzmann

Dissipation ⇒ r0↑ ⇒ T↓

Thompson+ 07

Non-thermalization

  Photospheric dissipation can reproduce Band

  ETh~ENon-th

without fine-tune in our rela. model

  Relativistic p, n may be important via pγ, nγ KI 10 Beloborodov 10

Lazzati & Begelman 10

EThermal~ ENon-th

Summary

  Γ>103 is possible   Internal shock synchrotron ⇒ keV-GeV-TeV γ

  Hot photosphere: ETh~ENon-th

  Photo.-Int.-Ext. shock model –  tdelay~[rth/c~L-1/5]~R*/c~0.3sec –  Neutrino – GeV γ Anti-Correlation –  Max synchrotron energy ⇒ CTA

3-D Rela. MHD Simulation

T. Inoue, Asano & KI in preparation

Contact me for preprints (~10 copies)! Richtmyer-Meshkov turbulence

Magnetic Field Amplification

0.01 0.1 1 10 100

10-1

10-2

10-3

10-4

10-5

10-6

10-7

! B

time : t [ Lz/c ]

t-0.7

  εB~0.1 is possible   In Eddy turnover time, exponential grow + power-law decay   Depends on εB,ini ⇒ Bring diversity   Amplification does not depend on Δn   Rela. Turbulence is not possible   ΠL < 2%

T. Inoue, Asano & KI in preparation

GeV Onset Delay

Proton Thermalization Thick ⇒ Thin [Baryon-rich ⇒ Barion-less]

Max Synchrotron Energy

€

′ t acc = ′ t cool

€

νmaxcool =

mec2

αΓ ~ 500 GeV Γ

104

€

′ t acc = ′ t dyn

€

νmaxdyn ~ 1 GeV Γ

6 ×104

−6

GRB 090926 Break??

A target for CTA

Very High Lorentz Factor (VHLF) case

Wang+ 09 Piran & Nakar 10 Barniol Duran & Kumar 10

KI 10

€

νFν

€

νFν

€

νFν

Time

MeV γ

GeV γ

TeV ν

Time

Time

€

η

Time

€

ηk1pp thin

pp thick

pp→π→ν εν~Γm

2mπc2>0.1TeV

TeV ν – GeV γ  Anti-Correlation

Baryon-less

Baryon-rich

Necessary Mass Loading

•  Ep~(Γm/rm)1/2 L1/4~L1/2 (S-B law + Yonetoku) •  (Two mass collision)

⇒

€

Γm ~ L˙ M c 2

1 2

M ! 10!5 M" s!1 r!2m,10

(Isotropic Rate)

Only depends on the environments Therefore, if progenitors are similar, the Epeak-L relations are reproduced