Probingthe(extragalactic(cosmic2ray(origin(with( gamma2ray...
Transcript of Probingthe(extragalactic(cosmic2ray(origin(with( gamma2ray...
N. Globus, D. Allard, E. Parizot and T. Piran, 2017, ApJ Letters, 839, 2
PoS (ICRC2017) 516
Probing the extragalactic cosmic-‐ray origin with gamma-‐ray and neutrino backgrounds
The UHECRs interact with 1) extragalactic magnetic fields 2) extragalactic photon backgrounds
source
Gamma-‐ray and neutrinos as probe of UHECR sources
energy losses => emission of
secondary messengers
ν, γ
ν, γ
ν, γ
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
ElectromagneBc cascades
γ+γEBLà e++e- pair production
e+γEBLà e'+γ ICS
=> The cosmic evolu/on of cosmic-‐ray sources have a strong influence on the cosmogenic neutrinos and photons fluxes
=>The νs energy range is PeV-‐EeV, the γ-‐rays cascade down to GeV-‐TeV
Allard 05
Mixed composition model
17.0 17.5 18.0 18.5 19.0 19.5 20.0 20.5log10 E (eV)
1023
1024
1025
E3 dN/d
E (e
V2 m-2s-1
sr-1) Auger (2013)
KG EPOS-LHCKG electron rich (H+He)Total extragal. (GRBs) with β= 2.0 to 2.5 (indicated)
Total Gal + extragal. (GRBs) with β= 2.4 and β= 2.5
H+He Gal + extragal (GRBs) β= 2.4 and 2.5
2.52.4
Total Galac/c + extragalac/c
Total light (H+He)
Propagated spectrum
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
Phenomenological mixed composi/on model:
1) EGCR: hard nuclei spectra + spectral index of the proton component 2.0 < β < 2.5 The proton spectrum needs to be soMer to fit Kascade-‐GRANDE data => it will contribute significantly to the expected cosmogenic γ-‐ray flux "Low-‐Emax" model => less νs due to the lack of cosmic rays accelerated above the pion producBon threshold
2) GCR: rigidity dependent (Emax(p) = knee energy)
Injec/on spectra (EGCR)
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
109 1010 1011 1012
E (eV)
1
10
100
1000E2 J(
E) [e
V.cm
-2.s
ec-1.s
r-1]
EGB Model A Model Buncertainties in the modeling of the Galactic foreground
UHECR from GRBs, β= 2.0 to 2.5
misAGN
SFG
UHECR from non evolving sources, β= 2.0 to 2.5
blazars
UHECR (GRBs) + misAGN + SFG + blazars
UHECR (non evol) + misAGN + SFG + blazars
Resulting gamma-‐ray fluxes
Two different models for the Galactic foreground(Ackermann+ 2015)
Globus, Allard, Parizot and Piran 2017, ApJ LeZers, 839, 2
sum of all contributions
- SFGs (Ackermann et al. 2012, Fermi Collab.)- misaligned AGNs (Inoue 2011) - blazars (Ajello et al. 2015)
seems compatible with Model B...
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
109 1010 1011 1012
E (eV)
100
1000E2 J(
E) [e
V.cm
-2.s
ec-1.s
r-1] EGRB Model A Model B
uncertainties in the modeling of the Galactic foreground
UHECR (GRBs) + other contributionsUHECR (GRBs) + lower limit of other contributionsother contributions (SFG + misAGN + blazars)lower limit of other contributionsUHECR (GRBs) (β= 2.0 to 2.5)
...even compatible with Model A if one consider the uncertainties on the SFG, misAGN and blazars models
+ uncertainties in the Galactic foreground ?
Resulting gamma-‐ray fluxes (GRB or SFR)
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
(Z16) (A16)
What about most recent estimates of PS contributions ?
2 recent studies: - Ackermann et al. 2016 (A16)- Zechlin et al. 2016 (Z16) (based on a method by Malyshev & Hogg 2011)
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
(Z16) (A16)
What about most recent estimates of PS contributions ?
2 recent studies: - Ackermann et al. 2016 (A16)- Zechlin et al. 2016 (Z16) (based on a method by Malyshev & Hogg 2011)
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
0 1 2 3 4 5 6α
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
z max
GRB
SFR
MLLAGN
HLLAGN
clusters
BL Lacs
80%
90%
100%
110%
120%
130%
104%
117%
130%
143%
156%
169%
% all contributions to EGB Model A % all contributions to EGB Model B Band 4 (10.4 - 50 GeV)
Central value of PS+misAGN+SFG models
Allowed cosmological evolutions
TDEs?
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
Resulting neutrinos fluxes
1015 1016 1017 1018 1019 1020
E (eV)
0.01
0.10
1.00
10.00
100.00E2 J(
E) [e
V.cm
-2.s
ec-1.s
r-1]
IceCube
ARIANNA (5 yrs)
GRAND (3 yrs)
β = 2.0
2.5
mixed composition GRB (as main UHECR sources) non evol. (as main UHECR sources)
1015 1016 1017 1018 1019 1020
E (eV)
0.01
0.10
1.00
10.00
100.00
E2 J(E)
[eV.
cm-2.s
ec-1.s
r-1]
IceCube
ARIANNA (5 yrs)
GRAND (3 yrs)
pure proton sources GRB (as main UHECR sources) non evol. (as main UHECR sources) FR-II (as main UHECR sources)
1015 1016 1017 1018 1019 1020
E (eV)
0.01
0.10
1.00
10.00
100.00E2 J(
E) [e
V.cm
-2.s
ec-1.s
r-1]
IceCube
ARIANNA (5 yrs)
GRAND (3 yrs)
β = 2.0
2.5
mixed composition GRB (as main UHECR sources) non evol. (as main UHECR sources)
1015 1016 1017 1018 1019 1020
E (eV)
0.01
0.10
1.00
10.00
100.00
E2 J(E)
[eV.
cm-2.s
ec-1.s
r-1]
IceCube
ARIANNA (5 yrs)
GRAND (3 yrs)
pure proton sources GRB (as main UHECR sources) non evol. (as main UHECR sources)
pure protons
mixed composition
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
Summary
- The mixed composition model is compatible with the spectrum and composition data (Globus, Allard, Parizot Phys. Rev. D 92, 021302) and is consistent with the anisotropy constraints on galactic protons (Tinyakov +16) - We showed that this model is compatible with both the most recent Fermi-LAT measurements and with current IceCube limits (Globus, Allard, Parizot & Piran ApJ LeZers, 839, 2)Only very strong evolution (FR-II) are excluded by the current observations
- There is a large uncertainty in the Galactic foreground subtraction=> neutrinos will help us to distinguish between models (proton "dip" model seems to be already ruled out for SFR and stronger evolution see Heinze +16)
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
thank you
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
BACK-‐UP
ICRC 2017, 12-‐20 July, Bexco, Busan, Korea
Resulting composition
15 16 17 18 19 20log10 E (eV)
0.01
0.10
1.00
Rela
tive a
bundance
1H
1H galactic
He
Z=3-8
Z=21-26
Z=21-26 galactic
17.0 17.5 18.0 18.5 19.0 19.5 20.0log10 E (eV)
600
650
700
750
800
850
< X
max >
(g. cm
-2)
proton
Fe
SIBYLL 2.1
QGSJet II-4
EPOS-LHC
17.0 17.5 18.0 18.5 19.0 19.5 20.0log10 E (eV)
0
20
40
60
80
!X
max (
g. cm
-2)
proton
Fe
SIBYLL 2.1
QGSJet II-4
EPOS-LHC
17.0 17.5 18.0 18.5 19.0 19.5 20.0log10 E (eV)
600
650
700
750
800
850
< X m
ax >
(g. c
m-2)
proton
Fe
Auger LOFAR
SIBYLL 2.1 QGSJet II-4EPOS-LHC
17.0 17.5 18.0 18.5 19.0 19.5 20.0log10 E (eV)
0
20
40
60
80
σX m
ax (g
. cm
-2)
proton
Fe
SIBYLL 2.1 QGSJet II-4EPOS-LHC
⇒ The model provides a good descrip/on of the evolu/on of the composi/on PredicBon: the dominant class of nuclei between ∼6 1018 eV and ∼5 1019 eV should be CNO
Globus, Allard and Parizot, 2015, Phys. Rev. D 92, 021302
Extragalactic γ-ray sources
EGRB spectrum by Fermi Large Area Telescope (Fermi LAT) collaboraBon between 100 MeV and 820 GeV
(Ackermann et al. 2015) (Ackermann et al. 2015)
• resolved: blazars
• unresolved: misaligned AGNs, SFGs,...
• truly diffuse in origin: - the electromagnetic cascades initiated by both very high energy γ-rays and UHECRs interacting with the EBL - dark matter annihilation/decay
Comparison with total EGB
(considering the mean values of the SFG+misAGN models)