Dip and Ankle Models
Aloisio, Berezinsky, Gazizov 2012
Heavy nuclei have been in the spotlight, while the dip model (proton model) agrees with the spectrum and Xmax.
CRs and PeV neutrinos
If all high-energy CRs are extra galacitic, …
Kalashev, Kusenko, Essey 2013
CRs are all proton?
AGNs?
Takami & Sato 2009
An anisotropy analysis resulted inthe source density:
-34 Mpc 10−≥
However, the density of FR-II radiogalaxies is…
-38 Mpc 103~ −×
GRB?Other transients?
UHECRs and GRBs
We need 5x1043 ergs/Mpc3/yr above 1019 eV as the local production rate of UHECRs. This is close to the local release rate of gamma-rays from GRBs!
See Waxman arXiv:1010.5007
Energy
E F(E)
MeVγ-ray=energy of electrons
100GeV 1020 eV
1019 eV
Comparable •The integrated proton energy should be 10-30 times the gamma-ray energy.•But, the gamma-ray energy per burst is huge; the isotropic energy is 1052-1055 erg.
Protons
eV10@ 19
γ≈≡ξ UUUU pepacc //Murase, Ioka, Nagataki, Nakamura 2008
Fermi Results for GRBs
GRB 080916C Abdo+ 2009
Short GRB 090510Ackermann+ 2010
900>Γ Extra component
GRB 090902B Abdo+ 2009
Photospheric?
Delayed Onsets in GeV
Photon signature of proton acceleration
Asano, Guiriec & Meszaros 2009
GRB 090510
200/10/ 3
=
=
γ
−γ
LLUU
p
B
Weak magnetic field ->enhance SSC component,but low cascade efficiency
εf(ε) [erg/cm2/s]
ε [eV]
e-e+-SYN
Total
R=1014 cm, Γ=1300, Up/Uγ=3, UB/Uγ=1
µ-SYNe-e+-IC
Band-comp.
102 104 106 10810-7
10-6
10-5
Asano, Inoue and Meszaros 2010
Do not need SSC
⇒ strong B⇒ high cascade efficiency⇒ Energies of protons and photons are comparable.
GRB 090902B
See Vietri 1997; Dermer & Atoyan 2006 etc.• p+γ→p(n)+π0(π+)
• p+γ→p+ e+ + e-
• π0→γ+γ, π+→μ+ +νμ
• γ+γ→ e+ + e-
Hadronic model for naked eye GRB
εf(ε) [erg/cm2/s]
ε [eV]
e-e+-SYN
Total
R=1016 cm, Γ=1000, Up/Uγ=45, UB/Uγ=3
e-e+-IC
Band-comp.µ-SYN
p-SYN
π-SYN
100 102 104 106 108 1010 1012
10-7
10-6
10-5
Asano, Inoue and Meszaros 2010Bright optical⇒No Synch. Self-abs.⇒Need high Γ⇒Easy to release GeV photons as well
High Γ⇒ low cascade efficiency⇒ Large proton energy again.
Naked-eye GRB 080319BRacusin+ 2008
Optical excess
Synch?
SSC?
SSC modelMilagro upper limit
Upper limit on proton acceleration by IceCube
Abbasi+2012
•"Benchmark"=Γ=300, δt=10ms, Lp/Lγ=10
1016eV1016eV
Abbasi+2011
Neutrinos in Alternative Emission Models
Zhang & Kumar 2013 Photosphere+pn-collision
Murase, Kashiyama & Meszaros 2013
Asano & Meszaros 2013
Neutrinos from photosphere
Internal shock Magnetically driven jet
Baryonic jet
The equipartition leads to low neutrino flux.(In those models, GRBs are not UHECR source.)
Recent detection of 2 neutrinos
Proton acceleration at the photosphere
Gao, Asano, Meszaros 2012
Time-dependent calculation
• Relativistically expanding shell (from R=R0)
• Synchrotron
• Inverse Compton (Thomson scat – Klein-Nishina regime)
• Synchrotron self-absorption
• Electron-positron pair creation
• Adiabatic cooling
• Photon escape
• Lagrangian scheme in energy space
• p(n)+γ→p(n)+π0(π+)
• p(n)+p→p(n)+p+π0(π+)
• p+γ→p+ e+ + e-
• π0→γ+γ, π+→μ+ +νμ
• μ+ →e+ + νμ + νe
• Synchrotron from p, π+ ,μ+
• Inverse Compton from p, π+ ,μ+
See also Pe’er & Waxman 2005, Pe’er2008, Belmont+ 2008, Vurm & Poutanen2009, Bosnjak+ 2009, Daigne+ 2011
Asano & Meszaros 2011 & 2012
Lightcurve
Spectra
Usual internal shock model
R0Γ
One-zone approximation in a shell
Time-Dependent Simulation
R0=1015 cm, Γ=800,Ee=1052 erg, Ep=1053 erg,UB/Ue=0.1 (B∝1/R)ε'min=1.4 GeV
Asano & Meszaros 2012
Broad and delayed light curvein GeV-TeV range.→ Hadronic signature
In this method, the photon and neutrino spectra are consistent!(Remind that the top-down UHECR model is rejectedby the absence of the secondary particles)
Variability Timescale
Arimoto, Kawai, Asano+ 2010
HETE-2
Pulse timescale
Nakar & Piran 2002Log-normal: σ=0.77
The universality of the variability timescale =10ms is not established.
Revisiting the classical model
Pulse timescale
Nakar & Piran 2002Log-normal: σ=0.77
Bhat 2013
δt [s]0.01 0.1 100.10.20.30.40.50.60.70.80.9
11.11.2
9-bin
Emission radius
2~ ΓtcR δ
Time-dependent simulation
ε [eV]
εf(ε) [erg]
δt=0.01s
Photon
Proton/Neutron
Neutrino
Neutron-conversion Magnetic decay
1052 erg/s
δt=0.03s
δt=0.1s
δt=0.3s
δt=1.0s
105 1010 1015 10201047
1048
1049
1050
1051
1052
1053
ε [eV]
εf(ε) [erg]
1051 erg/s
1052 erg/s
1053 erg/s
1054 erg/s
Photon
Proton/Neutron
Neutrino
Neutron-conversion Magnetic decay
δt=0.1 s
105 1010 1015 10201047
1048
1049
1050
1051
1052
1053
Numerical code: Asano & Meszaros 2012
Spectra from one pulse
1.0 ,10 Bp ==γγ LL
LL
300=Γ
Revisiting the classical model
Wanderman & Piran 2010
Luminosity function
Redshift distribution
1.2)1( z+ 4.1)1( −+ z
Liso [erg/s]
Eiso [erg]
1e+50 1e+51 1e+52 1e+53 1e+54 1e+551e+50
1e+51
1e+52
1e+53
1e+54
1e+55
1e+56
Based on Ghirlanda+ 2012
+ Yonetoku relation
Liso [erg]1e+50 1e+51 1e+52 1e+53 1e+540.0001
0.001
0.01
0.1 9-bin
Average spectra from a GRB
ε [eV]
εf(ε) [erg]
All protons
Escaped neutrons
Neutrinos
109 1012 1015 1018 10211049
1050
1051
1052
Optimistic casefor UHECR production.
Pessimistic case
Liso [erg]1e+50 1e+51 1e+52 1e+53 1e+540.0001
0.001
0.01
0.1
Neutron-conversion model
1.0 ,10 Bp ==γγ LL
LL
300=Γ
0.4%0.09%
ε [eV]
ε2J(ε) [erg/cm2/s/sr]
Neutrino
IC40+59
Auger
CRs
GZK-Neutrino
1014 1015 1016 1017 1018 1019 102010-14
10-13
10-12
10-11
10-10
Bright GRBs are inconsistent with the benchmark
Maselli+ 2013
GRB 130427A
ε [eV]
εf(ε) [erg] 1053.5 erg/s
Γ=300, R=1014cm
103 104 105 106 107 108 1091051
1052
L~1053.5 erg/s
Cascade emission dominates!
Model calculation
High Γ, or low Lp
Optimistic model
1.0 ,10 Bp ==γγ LL
LL
300=Γ
UHECR escapingfrom R=3R0
ε [eV]
ε2J(ε) [erg/cm2/s/sr]
Neutrino
IC40+59
AugerCRs
GZK-Neutrino
1014 1015 1016 1017 1018 1019 102010-14
10-13
10-12
10-11
10-10
Further 10times CR Loading
ε [eV]
ε2J(ε) [erg/cm2/s/sr]
NeutrinoIC40+59
Auger
CRs
GZK-Neutrino
L<1053.5 erg/s
IC2012
1014 1015 1016 1017 1018 1019 102010-14
10-13
10-12
10-11
10-10
10-9
Ankle model withoptimistic CR escape
Just assuming enhancement of CR production rate.
Not verified the consistency with the secondary gamma-ray signals.
Summary
• IceCube constrained only neutrinos from a small fraction of GRBs (bright end).
• Most of such GRBs are not likely the source of UHECRs.
• Highest energy UHECRs can be originated from GRBs, but it is not straightforward to agree with the flux at 1019eV (ankle).
• The energy budget allows more protons for usual GRBs.
• Higher Γ for brighter GRBs? This further suppresses the neutrino flux.