high energy neutrinos and gamma-ray bursts

High Energy Neutrinos High Energy Neutrinos andand

Gamma-Ray BurstsGamma-Ray BurstsKohta Murase (YITP)Kohta Murase (YITP)

S. Nagataki, K. Ioka, T. NakamuraK. Asano, S. Inoue, H. TakamiK. Sato, F. Iocco, P.D. Serpico

Neutrinos as a Probe of Cosmic-Ray AccelerationNeutrinos as a Probe of Cosmic-Ray Acceleration Astrophysical Accelerators (GRB, AGN, Cluster of Galaxies…) → cosmic-rays accelerated above TeV even up to ZeV

Neutrinos → good evidence of cosmic-ray acceleration

(Especially useful as a probe of ~100 PeV energy cosmic-rays)

pp/ pγ → π , K 　→ ν , γ

pp/pγ reaction

GRB (talk by Prof. Meszaros)

Merits! - time and position coincidence

• Testing the shock model (baryonic or not?)

• Magnetic field/amount of baryons• The origin of observed UHECRs?

taken from IceCube homepage

km3 telescopes (IceCube/KM3Net)Various model predictions have become testable

Cosmic-rays → Deflection by magnetic fields (talk by Dr. Takami)Gamma-rays above TeV → 　 Attenuation by CMB and CIB (talk by Dr. Asano)

Plan of TalkPlan of Talk

Model-Predictions for High-Energy Neutrinos from Astrophysical Sources

1. Neutrino Emission & Gamma-Ray Bursts

a. Pre-Swift Predictions (Prompt Emission)

b. Swift-Era Predictions (Flares and so on)

c. Neutrinos and Progenitors

2. Connection between Astrophysical Neutrino Sources and High-Energy Cosmic-Rays

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Gamma-Ray Bursts

Afterglows Ep,max ~ ZeV

EeV ν, GeV-TeV γ

Prompt EmissionEp,max ~ EeV-ZeV

PeV ν, GeV-TeV γ

Below Photosphere

Ep,max ~ PeV-EeV

TeV-PeV ν, invisible γ

Meszaros (2001)

Flares/Early AfterglowsEp,max ~ EeV

PeV-EeV ν, GeV γ

•Treatment of pγreaction: 　Rectangular approx.→More sophistication• Inclusion of various cooling processes 　•Treatment of the GRB rate history: 　GRB rate models→e.g. Guetta et al. (04,07)

OutlineOutlinePrompt (Waxman & Bahcall 97), Afterglow (Waxman &

Bahcall 00/Dermer 02)•Assumption that observed UHECRs come from GRBs (in original works)•Prediction of neutrinos associated with prompt and afterglow emission

KM & Nagataki, PRD, 73, 063002 (2006)

+Motivated by the recent Swift’s discoveries,

we have predicted new possibilities of neutrinos and cosmic rays.KM & Nagataki, PRL, 97, 051101 (2006) KM, Ioka, Nagataki, & Nakamura, ApJL, 651, L5 (2006)

Δ-resonance

KM, PRD, 76, 123001 (2007)

(And many studies, e.g., Halzen & Hooper 99, Guetta et al. 04, Asano 05)

Prompt Emission from Classical (High-Luminosity) GRBs

Internal Shock ModelPeV ν, GeV-TeV γ

(Waxman & Bahcall 97)

Meszaros (2001)

AfterglowsExternal Shock Model

EeV ν, GeV-TeV γ (Waxman & Bahcall 00)

(Dermer 02)

Prompt Neutrino EmissionPrompt Neutrino Emission

r~1013-1015cm

•Inner range (~1013 cm)neutrino efficient, UHECRs impossible•Middle range (~1014 cm)neutrino efficient, UHE proton possible•Outer range (~1015 cm)neutrino inefficient, UHE nuclei survive

large uncertainties...

Γ=300, Uγ=UB

EGRB,γ=1053 ergs (A&B)

A: muon events ~ 0.1B: muon events ~ 0.01

C: muon events ~ 1(C is a very extreme

case)

Only nearby/energetic bursts can be promising

(r-determination ← GLAST (e.g., KM & Ioka 08))

A r~1013.5 cm

B r~1014.5 cm

z=1

The Cumulative BackgroundThe Cumulative Background

• ~10 events/yr by IceCube ( fiducial baryon load)• Our models are tested by AMANDA/IceCube group. The optimistic model is being constrained (Achterberg et al. 08)

fiducial baryon loadingEHECR ~ EGRB,γ

higher baryon loadingEHECR ~ 5 EGRB,γ

The key parameter – baryon loading 　 ΕHECR ≡ε2 N(ε)

Set A - r~1013-1014.5cm

Set B - r~1014-1015.5cm

Γ=102.5, Uγ=UB

KM & Nagataki, PRD, 73, 063002 (2006)

Current AMANDA limit

Towards testing the GRB-UHECR hypothesis through νs

Early AfterglowsEeV ν, GeV-TeV γ

(Dermer 07)(KM 07)

Prompt Emissionfrom Low-Luminosity GRBs

PeV ν, GeV-TeV γ(KM et al. 06)

(Gupta & Zhang 06)

Meszaros (2001)

FlaresPeV-EeV ν, GeV γ(KM &Nagataki 06)

Novel Results of Swift (XRF060218)Novel Results of Swift (XRF060218)

1. Low-luminosity (LL) GRBs?• e.g., GRB060218 (XRF060218) ・ The 2nd nearby event (~140Mpc) ・ Associated with a SN Ic ・ Thermal component (shock breakout?) ・ Much dimmer than usual GRBs (ELL,γ ~ 1050 ergs ~ 0.001 EGRB,γ)・ LL GRBs (e.g., XRF060218, GRB980425) → more frequent than HL GRBs (Local Rate ~ 102-3 Gpc-1 yr-3 ) (Soderberg et al. 06, Liang et al. 07

Guetta et al. 07 etc…)

Liang et al. (07)

dark brightR

ate

Luminosity

Neutrinos from LL GRBsNeutrinos from LL GRBsEx.) XRF060218-like burst•Prompt nonthrmal emission Epk ~ 5 keV

↑Internal shock model (e.g., Toma, Ioka, Sakamoto, & Nakamura 07)

•Prolonged thermal emission kT ~ 0.15 keV

KM, Ioka, Nagataki, & Nakamura, ApJL, 651, L5 (2006)

r/Γ2=fixed

D=10Mpc

Muon events ~ 1 event

Muon events ~ 0.1 event

See also Gupta & Zhang 07For early afterglowssee Yu, Dai, & Zheng (08)

Novel Results of Swift (Flares)Novel Results of Swift (Flares)

2. Flares in the early afterglow phase• Energetic (Eflare,γ ~ 0.1 EGRB,γ (Falcone et al. 07)) (Eflare,γ ~ EGRB,γ for some flares such as GRB050502b)•δt >~ 102-3 s, δt/T < 1 → internal dissipation models (e.g. late internal shock model)• Flaring in the (far-UV)/x-ray range (Epeak ~ (0.1-1) keV)• (Maybe) relatively lower Lorentz factors (Γ ~ a few×10)• Flares are common (at least 1/3 ~ 1/2 of LGRBs) (even for SGRBs)

Baryonic (possibly dirty fireball?) vs non-baryonic?↑neutrinos!

Flares

Burrows et al. (07)

EnergeticsEnergetics

Neutrino Energy Flux∝ Photopion (p→π)Production Efficiency

NonthermalBaryon Energy×Rat

e×

HL GRB(Waxman & Bahcall

97)

Flare(Murase & Nagataki

06)

LL GRB(Murase et al. 06)

(Gupta & Zhang 07)

Isotropic energy 1 ~0.01-0.1 0.001

Pion Production

Efficiency

1 10 1

Apparent Rate 1 1 ~100-1000 The contribution to

neutrino background1 ~0.1-1 ~0.1-1

↓Normalizing all the typical values for HL GRBs to 1

Hence, we can expect flares and LL GRBs are important!

Neutrino Predictions in the Swift EraNeutrino Predictions in the Swift Era

Possible dominant contribution in the very high energy region

KM & Nagataki, PRL, 97, 051101 (2006)

KM, Ioka, Nagataki, & Nakamura, ApJL, 651, L5 (2006)

Approaches to GRBs through high-energy neutrinos Flares→information on flare models (baryonic or nonbaryonic etc.)LL GRBs→νs as an indicator of far SNe associated with LL GRBs

ν flashes → Coincidence with flares/early AGs, a few events/yrνs from LL GRBs → little coincidence with bursts, a few events/yr

Flares (Eflare,γ = 0.1 EGRB,γ ) LL GRBs

(ELL,γ ~ 0.001 EGRB,γ )

HL GRBs

See also, Gupta & Zhang 07

Notes on Early Afterglow EmissionNotes on Early Afterglow Emissionshallow decay

・ Forward Shock Model (energy injection etc.)・ Reverse Shock Model (Genet et al. 07, Beloborodov 07)

・ Late Prompt Emission Model (Ghisellini et al. 07)

Typically Eshallow,γ ~ 0.1 EGRB,γ (Liang et al. 07)• RS-FS model: ν-detection by IceCube would be difficult…• Late prompt emission model: ν-detection may be possible.

t

Its origin is still controversial...

Prompt

KM, PRD, 76, 123001 (2007)

high baryon loadingEHECR ~ EGRB,γ

fiducial baryon loadingEHECR ~ Eshallow,γ

~ 0.1 EGRB,γ

steep decay

(For forward shock νs,see Dermer 02, 07)

Below Photosphere

TeV ν

(Meszaros & Waxman 01)

(Schneider et al. 02)

( Razzaque, Meszaros, & Waxman 03)

Meszaros (2001)

Below/Around PhotosphereBelow/Around Photosphere

pp reaction → based onGeant4 & SYBILL codes

Below/around the photosphere (even inside the star)Cosmic-ray acceleration could be still expected

(e.g., Meszaros & Waxman 01, Razzaque et al. 03)

(pp optical depth) ~ np σpp(r/Γ) >~ 0.1 → 　 pp reaction important

r=1012.5 cmΓ=100, UB=0.1Uγ

strong meson/muon cooling ↓

kaon-contribution is important (Ando & Beacom 05) (Asano & Nagataki 06)

Neutrinos and ProgenitorNeutrinos and Progenitor

Fig. from Razzaque, Meszaros, & Waxman

Fabio, KM et al., ApJ (08)

termination shockTermination shock → shock dissipation→ thermalization ~keV→ providing target photons (Meszaros & Waxman 01)

(pp neutrinos are not shown→)

Schneider et al. (POPIII)

Precursor = successful GRBs (GRB rate)

Choked = failed GRBs (SN Ibc rate)

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Connection betweenAstrophysical Neutrino

Sources and High-Energy Cosmic-Rays

GRB-UHECR HypothesisGRB-UHECR Hypothesis

3153

UHECRGpcyrergs~ 10E

－－ ergs10E53～

Possible but requiring high baryon loading…(Lower local rate leads to higher baryon load…)

The original argument (Waxman 95, Vietri 95)

Gpcyr1 31GRB

－－～

← UHECR-normalization (except for Flares)

Comparable

HL Prompt ~ 30 events/yrLL Prompt ~ 10 events/yr AG (ISM) ~ 0.1 events/yr 　AG (WIND) ~ 1 event/yrFlare ~ 2 events/yr (not UHECR source)

KM, PRD, 76, 123001 (07)

Notes: HL/LL GRBs and UHECRsNotes: HL/LL GRBs and UHECRs

UHECR production is possible in low-luminosity GRBs

KM, Ioka, Nagataki, & Nakamura, submitted (2008)

The source number density ← PAO, TA Burst Models → 　 Sensitive to effective EGMF strength

(structured + intergalactic)Necessity of future observations and theoretical studies

(see talk by Dr. Takami)

Notes: Heavy Nuclei?Notes: Heavy Nuclei?Wang, Razzaque, & Meszaros (2008)

KM, Ioka, Nagataki, & Nakamura, submitted (2008)

Γ=102.5

Γ=1000

Recent PAO results → (tentative) existence of heavier nuclei (Unger et al. 07) UHE nuclei production in GRBs (IS, RS, and FS models) and hypernovae → Possible at enough large radii r

Survival of UHE heavy nuclei→ neutrino “dark” 　→ TeV gamma-ray “bright” <escape of TeV gamma-rays>　　 + secondary delayed emission

(Totani 98, Asano & Inoue 07)

(KM, Asano, & Nagataki, ApJ (07), Takahashi, KM, et al., in prep. (08))

(talk by Dr. Asano)

Neutrinos from AGNNeutrinos from AGNThe most frequently discussed UHECR candidates

(talk by Prof. Blandford, Dr. Inoue)

Many theoretical papers on neutrinos(Szabo & Protheroe, Stecker et al., Rachen & Biermann, Muniz & Meszaros, Mannheim, Atoyan & Dermer…)

Ex.) Giant AGN Flare model (Farrar & Gruzinov 08)

r=1017.5 cmΓ=10

Muon event rate ~(0.1-1) events/yr

Neutrinos from Clusters of GalaxiesNeutrinos from Clusters of Galaxies

146

acsergs~ 10L －3145

HECRGpcyrergs~ 10E

－－

1.0~acc

KM, Inoue & Nagataki, to be submitted (08)KM, Inoue, & Nagataki, in prep. (08)

CGs ⇔ The origin of second knee cosmic-rays??CGs ⇔ The origin of second knee cosmic-rays??

Shock radius ~ virial radius→ Muon events ~ a few events/yr

Cluster shocks (e.g., accretion shocks) → Emax ~ Z 1019 eV may be possible 　

Diffusion from Central AGN Model (Berezinsky et al., Colafrancesco & Blasi)

(See talk by Dr. Inoue)

36

CGMpc~ 10n －

required Broken PL

Broken PL spectrum→ (0.1-1)% of EGRET limit

SN shock+ CG shock

GZK NeutrinosGZK Neutrinos

•Ankle model vs dip model → dip model leads to 10 PeV bump•Strong evolution model → detection in the near future (Yukusel & Kistler 07)

PAO limit

Takami, KM, Nagataki, Sato (08)

Auger 07 limit

Emax=1022eV

CMB+CIB(Best-fit model of Kneiske et al. 04)

High-Energy Neutrinos and GRBs: SummaryHigh-Energy Neutrinos and GRBs: Summary• We have performed more sophisticated calculations on

neutrino spectra under the internal/external model.　　→ Our results have been tested by AMANDA/IceCube.Our results have been tested by AMANDA/IceCube.• We have predicted new possibilities of neutrino emission

from GRBs, motivated by Swift observations. 1. Neutrinos from flares and early afterglowsNeutrinos from flares and early afterglows 2. Neutrino bursts from low luminosity (LL) GRBsNeutrino bursts from low luminosity (LL) GRBs• We can also expect other neutrino signals (CG, AGN etc).We can also expect other neutrino signals (CG, AGN etc).

• Neutrinos (and gamma-rays) are useful as a probe of cosmic-ray acceleration in astrophysical sources.

• If detected, we can obtain the important clues to models of the source and cosmic-ray acceleration.

• The connection between GRBs and UHECRs? • High energy neutrino astronomy will come soon!