[PPT] - Gamma-rays from CR sources Michael Kachelrie NTNU, Trondheim [] PowerPoint Presentation

SLIDE 1

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Gamma-rays from CR sources

Michael Kachelrieß NTNU, Trondheim

SLIDE 2

TeV gamma-rays from UHECR sources

10 12 14 16 18 20 22 Gpc 100M pc 10M pc M pc 100kpc 10kpc kpc log10(E/eV)

radio photon horizon γγ → e+e− CMB IR Virgo ⇓

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 2 / 34

SLIDE 3

TeV gamma-rays from UHECR sources

during propagation: “cosmogenic” photons in sources:

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 3 / 34

SLIDE 4

TeV gamma-rays from UHECR sources

during propagation: “cosmogenic” photons in sources:

galactic CR sources GRB: large redshift time-delay UHECR ↔ photons makes direct correlation impossible for small EGMF: auto-correlation nGRB ∼ τ ˙

nGRB < nAGN

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 3 / 34

SLIDE 5

TeV gamma-rays from UHECR sources

during propagation: “cosmogenic” photons in sources:

galactic CR sources GRB: large redshift time-delay UHECR ↔ photons makes direct correlation impossible for small EGMF: auto-correlation nGRB ∼ τ ˙

nGRB < nAGN

AGN: jets: small densities, B core: high B, large UV and IR densities, τpγ ∼ 1 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 3 / 34

SLIDE 6

HESS observations of M87:

Date

12/1998 12/2000 12/2002 12/2004 12/2006

)

1

s

2

(E>730GeV) (cm Φ

0.0 0.5 1.0 1.5

12

10 ×

)

1

s

2

f(0.2-6 keV) (erg cm

20 40

12

10 ×

2003 2004 2005 2006 H.E.S.S. average HEGRA Chandra (HST-1) Chandra (nucleus)

B

09/Feb 16/Feb )

1

s

2

(E>730GeV) (cm Φ 2 4 6

12

10 ×

Feb. 2005

A

09/Mar 16/Mar March 2005 30/Mar 06/Apr April 2005 Date 04/May 11/May May 2005

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 4 / 34

SLIDE 7

HESS observations of M87:

Date

12/1998 12/2000 12/2002 12/2004 12/2006

)

1

s

2

(E>730GeV) (cm Φ

0.0 0.5 1.0 1.5

12

10 ×

)

1

s

2

f(0.2-6 keV) (erg cm

20 40

12

10 ×

2003 2004 2005 2006 H.E.S.S. average HEGRA Chandra (HST-1) Chandra (nucleus)

B

09/Feb 16/Feb )

1

s

2

(E>730GeV) (cm Φ 2 4 6

12

10 ×

Feb. 2005

A

09/Mar 16/Mar March 2005 30/Mar 06/Apr April 2005 Date 04/May 11/May May 2005

fast variability excludes acceleration along kpc jet acceleration in hot spots marginally okay favors acceleration close to SMBH

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 4 / 34

SLIDE 8

HESS & Veritas observations of M87:

Date

12/1998 12/2000 12/2002 12/2004 12/2006

)

1

s

2

(E>730GeV) (cm Φ

0.0 0.5 1.0 1.5

12

10 ×

)

1

s

2

f(0.2-6 keV) (erg cm

20 40

12

10 ×

2003 2004 2005 2006 H.E.S.S. average HEGRA Chandra (HST-1) Chandra (nucleus)

B

09/Feb 16/Feb )

1

s

2

(E>730GeV) (cm Φ 2 4 6

12

10 ×

Feb. 2005

A

09/Mar 16/Mar March 2005 30/Mar 06/Apr April 2005 Date 04/May 11/May May 2005

fast variability excludes acceleration along kpc jet acceleration in hot spots marginally okay favors acceleration close to SMBH

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 4 / 34

SLIDE 9

Outline of the talk

1 Introduction 2 Gamma-rays produced in UHECR sources How do get multi TeV gamma-rays out off AGN cores:

electromagnetic cascades in UHECR sources

3 Cosmogenic fluxes: Cosmogenic neutrino limits from Fermi-LAT Cosmogenic photons: diffuse flux Secondary photons from CR point sources 4 Lower limit on EGMF using gamma-rays 5 Summary Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 5 / 34

SLIDE 10

Outline of the talk

1 Introduction 2 Gamma-rays produced in UHECR sources How do get multi TeV gamma-rays out off AGN cores:

electromagnetic cascades in UHECR sources

3 Cosmogenic fluxes: Cosmogenic neutrino limits from Fermi-LAT Cosmogenic photons: diffuse flux Secondary photons from CR point sources 4 Lower limit on EGMF using gamma-rays 5 Summary Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 5 / 34

SLIDE 11

Outline of the talk

1 Introduction 2 Gamma-rays produced in UHECR sources How do get multi TeV gamma-rays out off AGN cores:

electromagnetic cascades in UHECR sources

3 Cosmogenic fluxes: Cosmogenic neutrino limits from Fermi-LAT Cosmogenic photons: diffuse flux Secondary photons from CR point sources 4 Lower limit on EGMF using gamma-rays 5 Summary Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 5 / 34

SLIDE 12

Outline of the talk

1 Introduction 2 Gamma-rays produced in UHECR sources How do get multi TeV gamma-rays out off AGN cores:

electromagnetic cascades in UHECR sources

3 Cosmogenic fluxes: Cosmogenic neutrino limits from Fermi-LAT Cosmogenic photons: diffuse flux Secondary photons from CR point sources 4 Lower limit on EGMF using gamma-rays 5 Summary Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 5 / 34

SLIDE 13

Astrophysical sources Centaurus A

Multi-messenger astronomy with Cen A?

+ 2 events correlated with Cen A within 3.1◦ + more events close-by

[Gorbunov et al. ’07, Fargione ’08, Rachen ’08 ]

+ general correlation with AGN − confusion with LSS? − no confirmation by HiRes − tension to PAO chemical composition − Emax for most AGN (incl. Cen A) high enough? correlations with AGN: independent/additional evidence? Cen A closest AGN ⇒ good test case for multi-messenger astronomy: accompanying γ-ray and neutrino fluxes?

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 6 / 34

SLIDE 14

Astrophysical sources Centaurus A

Results for acceleration close to the core: α = 1.2

initial protons final protons total neutrinos γ γ

HESS CGRO FERMI PAO

8 10 12 14 16 18 20 13 14 15 16 17 18

log10 (E/eV) log10 (E 2Φ/eV km-2 yr-1)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 7 / 34

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Astrophysical sources Centaurus A

Results for acceleration close to the core: α = 2

initial protons final protons total neutrinos γ γ

HESS CGRO FERMI PAO

8 10 12 14 16 18 20 14 15 16 17 18 19

log10(E/eV) log10 (E 2Φ/eV km-2 yr-1) promising test case for HESS / FERMI γ-ray spectrum rather insensitive to α

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 7 / 34

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Astrophysical sources Centaurus A

HESS observations of Cen A

no variability

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 8 / 34

SLIDE 17

Astrophysical sources Centaurus A

HESS observations of Cen A

no variability consistent with point source

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 8 / 34

SLIDE 18

Astrophysical sources Centaurus A

HESS observations of Cen A

no variability consistent with point source HE emission from central region (1’ 1.1 kpc)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 8 / 34

SLIDE 19

Astrophysical sources Centaurus A

Comparison to recent HESS and FERMI observations

initial protons final protons γ γ

HESS Fermi broken α=2 α=1.2 PAO

8 10 12 14 16 18 20 14 15 16 17 18 19 20

log10(E/eV) log10 (E 2Φ/eV km-2 yr-1)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 9 / 34

SLIDE 20

Astrophysical sources Centaurus A

Comparison to recent HESS and FERMI observations

initial protons final protons γ γ

HESS Fermi broken α=2 α=1.2 PAO

8 10 12 14 16 18 20 14 15 16 17 18 19 20

log10(E/eV) log10 (E 2Φ/eV km-2 yr-1) shape and normalization okay TeV γ-ray and neutrino source

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 9 / 34

SLIDE 21

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: a) (isotropic) source

injection spectrum Fγ(E) ∝ 1/E2

10 12 14 16 18 20 E2 F(E) log10(E/eV)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 10 / 34

SLIDE 22

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: a) (isotropic) source

: thin above 1016eV, ultra-rel. regime

10 12 14 16 18 20 E2 F(E) log10(E/eV)

⇓

Eγεγ m2

e

ultra-rel. regime

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 10 / 34

SLIDE 23

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: b) on EBL

photons above 1014eV cascade on EBL

10 12 14 16 18 20 E2 F(E) log10(E/eV)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 11 / 34

SLIDE 24

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: b) on EBL

photons above 1014eV cascade on EBL : fill up GeV–TeV range

10 12 14 16 18 20 E2 F(E) log10(E/eV)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 11 / 34

SLIDE 25

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: b) on EBL

photons above 1014eV cascade on EBL : fill up GeV–TeV range

10 12 14 16 18 20 E2 F(E) log10(E/eV)

main criteria: LUHE, not shape

evidence for acceleration to UHECRs?

however: anisotropic UV field complicates picture already in source

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 11 / 34

SLIDE 26

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: collinear regime

isotropic

anisotropic

8 10 12 14 16 18 20

4
3
2
1

1 2 3 4

log10(E/eV) log10 τγγ

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 12 / 34

SLIDE 27

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: decaying muons

lint, UV lint, IR cutoff lint, IR no cutoff ldec,µ R 1

12 13 14 15 16 17 18 19 20

6
5
4
3
2
1

1 2

log10(E/eV) log10 (l/pc)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 13 / 34

SLIDE 28

Astrophysical sources Electromagnetic cascades in the source

Regenerating TeV photons: adding IR

lint, UV lint, IR cutoff lint, IR no cutoff ldec,µ R 1

12 13 14 15 16 17 18 19 20

6
5
4
3
2
1

1 2

log10(E/eV) log10 (l/pc)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 13 / 34

SLIDE 29

Astrophysical sources Electromagnetic cascades in the source

adding IR from a compact source:

E max = 1020 eV E max = 1019 eV E max = 1018 eV

HESS Fermi R IR = 1 pc

8 9 10 11 12 13 14 15 15 16 17 18 19 20

log10(E/eV) log10 (E 2Φ/eV km-2 yr-1)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 14 / 34

SLIDE 30

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

Photon and neutrino production relatively tight connected:

protons:

p + γ3K → p + π0 → p + 2γ n + π+ → p + 2e± + 4ν

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 15 / 34

SLIDE 31

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

Photon and neutrino production relatively tight connected:

protons:

p + γ3K →

p + π0 → p + 2γ

n + π+ → p + 2e± + 4ν

nuclei: A + γ3K → (A − 1) + n → (A − 1) + p + e− + νe connection to UHECRs looser Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 15 / 34

SLIDE 32

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

Photon and neutrino production relatively tight connected:

protons:

p + γ3K → p + π0 → p + 2γ n + π+ → p + 2e± + 4ν

nuclei: A + γ3K → (A − 1) + n → (A − 1) + p + e− + νe

cascade limit:

[Berezinsky, Smirnov ’75 ]

all energy in γ and e± cascades below ∼ 100 GeV

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 15 / 34

SLIDE 33

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

Photon and neutrino production relatively tight connected:

protons:

p + γ3K → p + π0 → p + 2γ n + π+ → p + 2e± + 4ν

nuclei: A + γ3K → (A − 1) + n → (A − 1) + p + e− + νe

cascade limit:

[Berezinsky, Smirnov ’75 ]

all energy in γ and e± cascades below ∼ 100 GeV Jγ(E) =    K(E/εX)−3/2 at E ≤ εX K(E/εX)−2 at εX ≤ E ≤ at E > εa

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 15 / 34

SLIDE 34

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

Photon and neutrino production relatively tight connected:

protons:

p + γ3K → p + π0 → p + 2γ n + π+ → p + 2e± + 4ν

nuclei: A + γ3K → (A − 1) + n → (A − 1) + p + e− + νe

cascade limit:

[Berezinsky, Smirnov ’75 ]

all energy in γ and e± cascades below ∼ 100 GeV Fermi-LAT measurement of EGRB: ωcas > 4π c ∞

E0

dE EIν(E) ≥ 4π c E0Iν(> E0) < ∼ 6 · 10−7 eV/cm3

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 15 / 34

SLIDE 35

Cosmogenic fluxes Neutrino limits from the EGRB

Comparison of Monte Carlo and analytical estimate

1e+11 1e+12 1e+13 1e+14 1e+15 1e+06 1e+07 1e+08 1e+09 1e+10 1e+11 1e+12 1e+13 1e+14 1e+15 E2*J(E) E/eV 100Mpc E-3/2

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 16 / 34

SLIDE 36

Cosmogenic fluxes Neutrino limits from the EGRB

Comparison of Monte Carlo and analytical estimate

1e+11 1e+12 1e+13 1e+14 1e+15 1e+06 1e+07 1e+08 1e+09 1e+10 1e+11 1e+12 1e+13 1e+14 1e+15 E2*J(E) E/eV 100Mpc 1000Mpc E-3/2 E-1.9

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 16 / 34

SLIDE 37

Cosmogenic fluxes Neutrino limits from the EGRB

Fermi-LAT vs. UHECR data:

[Berezinsky et al. ’10 ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 17 / 34

SLIDE 38

Cosmogenic fluxes Neutrino limits from the EGRB

Fermi-LAT vs. UHECR data:

[Berezinsky et al. ’10 ]

integrating EJ(E) gives bound ωcas < ∼ 6 · 10−7 eV/cm3

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 17 / 34

SLIDE 39

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

[Berezinsky et al. ’10 ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 18 / 34

SLIDE 40

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

[Ahlers et al. ’10 ]

104 105 106 107 108 109 1010 1011 1012 1013 1014 E [GeV] Emin = 1019 eV

AMANDA (3

µ)

AMANDA (

e,µ, )

BAIKAL (

e,µ, )

RICE (

e,µ, )

HiRes (3

x )

Auger (3 ) ANITA (

e,µ, )

IceCube (5 , 1yr) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 18 / 34

SLIDE 41

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

104 105 106 107 108 109 1010 1011 1012 1013 1014 E [GeV] Emin = 1019 eV

AMANDA (3

µ)

AMANDA (

e,µ, )

BAIKAL (

e,µ, )

RICE (

e,µ, )

HiRes (3

x )

Auger (3 ) ANITA (

e,µ, )

IceCube (5 , 1yr)

Main difference: expected IceCube sensitivity

end of exp. sensitivity for 1/E2 flux: 1017 vs. 1019 eV

verall sensitivity of IceCube

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 18 / 34

SLIDE 42

Cosmogenic fluxes Neutrino limits from the EGRB

Cascade limit for cosmogenic neutrinos

104 105 106 107 108 109 1010 1011 1012 1013 1014 E [GeV] Emin = 1019 eV

AMANDA (3

µ)

AMANDA (

e,µ, )

BAIKAL (

e,µ, )

RICE (

e,µ, )

HiRes (3

x )

Auger (3 ) ANITA (

e,µ, )

IceCube (5 , 1yr)

Main difference: expected IceCube sensitivity

end of exp. sensitivity for 1/E2 flux: 1017 vs. 1019 eV

verall sensitivity of IceCube

All plots for proton primaries

for nuclei reduced neutrino fluxes. . .

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 18 / 34

SLIDE 43

Cosmogenic fluxes Diffuse photons

Cosmogenic photons

[Hooper, Taylor, Sarkar ’10 ]

10-6 10-5 10-4 10-3 10-2 10-1 100 18.2 18.4 18.6 18.8 19 19.2 19.4 19.6 19.8 20

photon fraction log10Energy [eV]

Protons Iron

Emax,Z=(Z/26)x1021 eV α=2.0 B<3 pG

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 19 / 34

SLIDE 44

Cosmogenic fluxes Diffuse photons

Cosmogenic photons

[Hooper, Taylor, Sarkar ’10 ]

10-6 10-5 10-4 10-3 10-2 10-1 100 18.2 18.4 18.6 18.8 19 19.2 19.4 19.6 19.8 20

photon fraction log10Energy [eV]

Protons Iron

Emax,Z=(Z/26)x1021 eV α=2.0 B<3 pG

A > 1: photons suppressed by factor 10 compared to protons even proton: requires sensitivity improved by ∼ 100 large Emax and small α helps. . .

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 19 / 34

SLIDE 45

Cosmogenic fluxes Diffuse photons

Cosmogenic photons

[Hooper, Taylor, Sarkar ’10 ]

10-6 10-5 10-4 10-3 10-2 10-1 100 18.2 18.4 18.6 18.8 19 19.2 19.4 19.6 19.8 20

photon fraction log10Energy [eV]

Protons Iron

Emax,Z=(Z/26)x1022 eV α=2.0 B<3 pG

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 19 / 34

SLIDE 46

Cosmogenic fluxes Diffuse photons

Cosmogenic photons: dependence on α

[Gelmini, Kalashev, Semikoz ’05 ]

0.001 0.01 0.1 1 10 100 1e+19 1e+20 1e+21 j(E) E2 [eV cm-2 s-1 sr-1] E [eV] 1.5 2.0 2.7 1.5 2.0 2.7

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 20 / 34

SLIDE 47

Cosmogenic fluxes Secondary photons from point sources

Secondary photons from CR point sources

for d < few × 10 Mpc: UHE photons survive

[Taylor et al. ’09 ]

0.0001 0.001 0.01 0.1 1 10 100 1000 10000 18 18.5 19 19.5 20 20.5 21 21.5 22

Rate (>E) [yr-1] log10E [eV]

protons photons Source at 3.8 M pc α=2 Emax=1020 eV Emax=1021 eV Auger data (2007)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 21 / 34

SLIDE 48

Cosmogenic fluxes Secondary photons from point sources

Secondary photons from CR point sources

for d < few × 10 Mpc: UHE photons survive

[Taylor et al. ’09 ]

non-observation is no constraint, but observation identifies close source

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 21 / 34

SLIDE 49

Cosmogenic fluxes Secondary photons from point sources

Secondary photons from CR point sources

for d < few × 10 Mpc: UHE photons survive

[Taylor et al. ’09 ]

larger distance: UHE photons cascade down in TeV range

[Essey et al. ’10 ] universal shape, depending only on EBL and z

10-6 10-5 10-4 10-3 10-2 10-1 100 101 102 101 102 103 104 105 106 107 108 109 1010 1011 1012 E2 dN/dE, eV cm-2s-1 E, GeV 108 GeV 1010 GeV 1011 GeV

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 21 / 34

SLIDE 50

Cosmogenic fluxes Secondary photons from point sources

Secondary photons from CR point sources

for d < few × 10 Mpc: UHE photons survive

[Taylor et al. ’09 ]

larger distance: UHE photons cascade down in TeV range

[Essey et al. ’10 ] universal shape, depending only on EBL and z

10-6 10-5 10-4 10-3 10-2 10-1 100 101 102 101 102 103 104 105 106 107 108 109 1010 1011 1012 E2 dN/dE, eV cm-2s-1 E, GeV 108 GeV 1010 GeV 1011 GeV

large luminosities Leff ∼ 1047 − 1049erg/s in UHECR relatively small EGMFs in voids, B <

∼ 10−14 G

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 21 / 34

SLIDE 51

Gamma-rays and the EGMF

Gamma-rays and extragalactic magnetic fields (EGMF)

Origin of seed for EGMF is mysterious Seed required as input for EGMF simulations

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 22 / 34

SLIDE 52

Gamma-rays and the EGMF

Gamma-rays and extragalactic magnetic fields (EGMF)

Origin of seed for EGMF is mysterious Seed required as input for EGMF simulations

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 22 / 34

SLIDE 53

Gamma-rays and the EGMF

Gamma-rays and extragalactic magnetic fields (EGMF)

Origin of seed for EGMF is mysterious Seed required as input for EGMF simulations Observations only in clusters,

synchrotron halo: ⇒ B ∼ (0.1 − 1) µG Faraday rotation: ⇒ B ∼ (1 − 10) µG Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 22 / 34

SLIDE 54

Gamma-rays and the EGMF

Gamma-rays and extragalactic magnetic fields (EGMF)

Origin of seed for EGMF is mysterious Seed required as input for EGMF simulations Observations only in clusters,

synchrotron halo: ⇒ B ∼ (0.1 − 1) µG Faraday rotation: ⇒ B ∼ (1 − 10) µG

Aharonian, Coppi, V¨

lk ’94: Pair halos around AGNs

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 22 / 34

SLIDE 55

Gamma-rays and the EGMF

Gamma-rays and extragalactic magnetic fields (EGMF)

Origin of seed for EGMF is mysterious Seed required as input for EGMF simulations Observations only in clusters,

synchrotron halo: ⇒ B ∼ (0.1 − 1) µG Faraday rotation: ⇒ B ∼ (1 − 10) µG

Aharonian, Coppi, V¨

lk ’94: Pair halos around AGNs

Plaga ’95: EGMFs deflect and delay cascade electrons ⇒ search for delayed “echoes” of multi-TeV AGN flares/GRBs

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 22 / 34

SLIDE 56

Gamma-rays and the EGMF

Observer misaligned with jet:

[Neronov et al. ’10 ]

ext

O O

e+ + jet

bs

e− e− e

probability for misalignement p ∝ ϑobs ⇒ most blazars viewed with ϑobs ∼ ϑjet

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 23 / 34

SLIDE 57

Gamma-rays and the EGMF

Observer misaligned with jet:

[Neronov et al. ’10 ]

ext

O O

e+ + jet

bs

e− e− e

probability for misalignement p ∝ ϑobs ⇒ most blazars viewed with ϑobs ∼ ϑjet ⇒ halos are not symmetric

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 23 / 34

SLIDE 58

Gamma-rays and the EGMF

Observer misaligned with jet:

[Neronov et al. ’10 ]

ext

O O

e+ + jet

bs

e− e− e

probability for misalignement p ∝ ϑobs ⇒ most blazars viewed with ϑobs ∼ ϑjet ⇒ halos are not symmetric ⇒ time-delay is function of ϑ, Tdelay(ϑ) ∼ 3 × 106yr (ϑobs + Θjet) 5◦ ϑ 5◦

Michael Kachelrieß (NTNU Trondheim)

Gamma-rays from CR sources TeV Particle Astrophysics ’10 23 / 34

SLIDE 59

Gamma-rays and the EGMF

Asymmetric halos around TeV blazars (“GeV jets”):

1 0.1 0.01 0.001

ϑobs = 0◦ ϑobs = 3◦ ϑobs = 6◦ ϑobs = 9◦

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 24 / 34

SLIDE 60

Gamma-rays and the EGMF

“GeV jets”: B dependence

1 0.1 0.01 0.001

10−17 G 10−16 G 10−15 G 10−14 G

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 25 / 34

SLIDE 61

Gamma-rays and the EGMF

“GeV jets”: time dependence of flares

1 0.1 0.01 0.001

0 < Tdelay < 105 yr 3 × 106 yr< Tdelay < 107 yr

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 26 / 34

SLIDE 62

Gamma-rays and the EGMF

Lower limit on EGMF:

choose blazar: large z, stationary, low GeV, high multi-TeV emission

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 27 / 34

SLIDE 63

Gamma-rays and the EGMF

Lower limit on EGMF:

choose blazar: large z, stationary, low GeV, high multi-TeV emission TeV photons cascade down:

small EGMF: fill up GeV range “large” EGMF: deflected outside, isotropized Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 27 / 34

SLIDE 64

Gamma-rays and the EGMF

Lower limit on EGMF:

[F. Tavecchio et al. ’10, A. Neronov, I. Vovk ’10 ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 28 / 34

SLIDE 65

Gamma-rays and the EGMF

Lower limit on EGMF:

[F. Tavecchio et al. ’10, A. Neronov, I. Vovk ’10 ]

B > ∼ 10−15 G some dependence on ϑjet

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 28 / 34

SLIDE 66

Gamma-rays and the EGMF

Lower limit on EGMF:

[F. Tavecchio et al. ’10, A. Neronov, I. Vovk ’10 ]

B > ∼ 10−15 G some dependence on ϑjet no simulation of elmag. cascade with B what happens for structured B?

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 28 / 34

SLIDE 67

Gamma-rays and the EGMF

Lower limit on EGMF:

[MK, Ostapchenko, Tom` as ]

10-16 G 10-15 G 5×10-15 G 10-14 G 5×10-14 G

HESS Fermi

7 8 9 10 11 12 13 14

14
13
12
11

log10 (E 2F/erg cm-2 s-1) log10(E/eV)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 29 / 34

SLIDE 68

Gamma-rays and the EGMF

Lower limit on filling factor:

[MK, Ostapchenko, Tom` as ’10 ]

model filaments by a top-hat: 10 Mpc B = 0 B = 10−10 G

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 30 / 34

SLIDE 69

Gamma-rays and the EGMF

Lower limit on filling factor:

[MK, Ostapchenko, Tom` as ’10 ]

0.10 0.25 0.50 0.75 0.90

HESS Fermi

7 8 9 10 11 12 13 14

14
13
12
11

log10 (E 2F/erg cm-2 s-1) log10(E/eV)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 31 / 34

SLIDE 70

Gamma-rays and the EGMF

Lower limit on filling factor:

[MK, Ostapchenko, Tom` as ’10 ]

0.10 0.25 0.50 0.75 0.90

HESS Fermi

7 8 9 10 11 12 13 14

14
13
12
11

log10 (E 2F/erg cm-2 s-1) log10(E/eV)

linear filling factor > ∼ 50%

mainly 3-step cascade: γ → e± → γ photon mean free path Dγ(E) ∼ 1000–50 Mpc electron mean free path De(E) ∼ few kpc

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 31 / 34

SLIDE 71

Gamma-rays and the EGMF

Lower limit on filling factor:

[MK, Ostapchenko, Tom` as ’10 ]

0.10 0.25 0.50 0.75 0.90

HESS Fermi

7 8 9 10 11 12 13 14

14
13
12
11

log10 (E 2F/erg cm-2 s-1) log10(E/eV)

linear filling factor > ∼ 50%

mainly 3-step cascade: γ → e± → γ photon mean free path Dγ(E) ∼ 1000–50 Mpc electron mean free path De(E) ∼ few kpc ⇒ electrons are created “everywhere” and feel B only close to interaction point

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 31 / 34

SLIDE 72

Gamma-rays and the EGMF

EGMF in voids already observed?

[Ando, Kusenko ’10 ]

stack 170 brightest AGN

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 32 / 34

SLIDE 73

Gamma-rays and the EGMF

EGMF in voids already observed?

[Ando, Kusenko ’10 ]

stack 170 brightest AGN search for excess over PSF

359.5 0.5

0.5

0.5

Rel. RA (deg)
Rel. DEC (deg)

Counts M ap (3-10 GeV)

10 20 30 40 50 60 (counts) 359.5 0.5

0.5

0.5 Rel RA (deg) Rel DEC (deg)

M odel M ap (3-10 GeV)

10 20 30 40 50 (counts)

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 32 / 34

SLIDE 74

Gamma-rays and the EGMF

EGMF in voids already observed?

[Ando, Kusenko ’10 ]

stack 170 brightest AGN search for excess over PSF

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 32 / 34

SLIDE 75

Gamma-rays and the EGMF

EGMF in voids already observed?

[Ando, Kusenko ’10 ]

stack 170 brightest AGN search for excess over PSF

359.5 0.5

0.5

0.5

Rel. RA (deg)
Rel. DEC (deg)

Counts M ap (3-10 GeV)

10 20 30 40 50 60 (counts) 359.5 0.5

0.5

0.5 Rel RA (deg) Rel DEC (deg)

M odel M ap (3-10 GeV)

10 20 30 40 50 (counts)

⇒ explained by B ∼ 10−15 G (λB/1 kpc)−1/2 and λB < 10 − 100 kpc

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 32 / 34

SLIDE 76

Gamma-rays and the EGMF

EGMF in voids already observed?

[Ando, Kusenko ’10 ]

stack 170 brightest AGN search for excess over PSF

359.5 0.5

0.5

0.5

Rel. RA (deg)
Rel. DEC (deg)

Counts M ap (3-10 GeV)

10 20 30 40 50 60 (counts) 359.5 0.5

0.5

0.5 Rel RA (deg) Rel DEC (deg)

M odel M ap (3-10 GeV)

10 20 30 40 50 (counts)

lower limit B > ∼ 5 × 10−15 G requires λB < ∼ 0.1 kpc

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 32 / 34

SLIDE 77

Gamma-rays and the EGMF

EGMF already observed? Probably not. . .

[Neronov et al. ’10 ]

point source Crab shows the same “halo” as stacked AGN:

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 33 / 34

SLIDE 78

Gamma-rays and the EGMF

EGMF already observed? Probably not. . .

[Neronov et al. ’10 ]

point source Crab shows the same “halo” as stacked AGN: tail of PSF wrong (?), difference between “front” and “back” photons

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 33 / 34

SLIDE 79

Gamma-rays and the EGMF

Summary

multi-TeV photons from AGN cores require

photons in KN regime HE muons

⇒ hadronic models

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 34 / 34

SLIDE 80

Gamma-rays and the EGMF

Summary

multi-TeV photons from AGN cores require

photons in KN regime HE muons

⇒ hadronic models secondary photons:

chemical composition TeV sources ?? Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 34 / 34

SLIDE 81

Gamma-rays and the EGMF

Summary

multi-TeV photons from AGN cores require

photons in KN regime HE muons

⇒ hadronic models secondary photons:

chemical composition TeV sources ??

cascade limit from Fermi data reduced by factor ∼ 7

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 34 / 34

SLIDE 82

Gamma-rays and the EGMF

Summary

multi-TeV photons from AGN cores require

photons in KN regime HE muons

⇒ hadronic models secondary photons:

chemical composition TeV sources ??

cascade limit from Fermi data reduced by factor ∼ 7 lower limit on EGMF in voids B > ∼ 10−15 G

Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 34 / 34