Gamma-rays from CR sources Michael Kachelrieß NTNU, Trondheim []
TeV gamma-rays from UHECR sources 22 radio 20 18 log10(e /ev ) 16 photon horizon γγ e + e CMB 14 IR 12 10 kpc 10kpc 100kpc M pc Virgo 10M pc 100M pc G pc Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 2 / 34
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
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 n GRB τṅ GRB <n AGN Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 3 / 34
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 n GRB τṅ GRB <n AGN AGN: jets: small densities, B core: high B, large UV and IR densities, τ pγ 1 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 3 / 34
HESS observations of M87: A ) -1 s -12 10 6 Feb. 2005 March 2005 April 2005 May 2005-2 Φ(E>730GeV) (cm 4 2 B ) -1 s -2 Φ(E>730GeV) (cm 0 1.5 1.0 0.5 0.0 09/Feb -12 ) 10 16/Feb 09/Mar H.E.S.S. average H E G R A 16/Mar Chandra (HST-1) Chandra (nucleus) 30/Mar 2003 06/Apr 2004 2005 04/May 2006 11/May Date 12/1998 12/2000 12/2002 12/2004 12/2006 Date -12 10 40 20 0-1 s -2 f(0.2-6 kev) (erg cm Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 4 / 34
HESS observations of M87: A ) -1 s -12 10 6 Feb. 2005 March 2005 April 2005 May 2005-2 Φ(E>730GeV) (cm 4 2 B ) -1 s -2 Φ(E>730GeV) (cm 0 1.5 1.0 0.5 0.0 09/Feb -12 ) 10 16/Feb 09/Mar 16/Mar 30/Mar 06/Apr H.E.S.S. 2005 40 fast average variability excludes acceleration along kpc jet H E G R A acceleration Chandra (HST-1) in hot 2003 spots marginally okay Chandra (nucleus) favors acceleration close to SMBH 2004 04/May 2006 11/May Date 12/1998 12/2000 12/2002 12/2004 12/2006 Date -12 10 20 0-1 s -2 f(0.2-6 kev) (erg cm Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 4 / 34
HESS & Veritas observations of M87: A ) -1 s -12 10 6 Feb. 2005 March 2005 April 2005 May 2005-2 Φ(E>730GeV) (cm 4 2 B ) -1 s -2 Φ(E>730GeV) (cm 0 1.5 1.0 0.5 0.0 09/Feb -12 ) 10 16/Feb 09/Mar 16/Mar 30/Mar 06/Apr H.E.S.S. 2005 40 fast average variability excludes acceleration along kpc jet H E G R A acceleration Chandra (HST-1) in hot 2003 spots marginally okay Chandra (nucleus) favors acceleration close to SMBH 2004 04/May 2006 11/May Date 12/1998 12/2000 12/2002 12/2004 12/2006 Date -12 10 20 0-1 s -2 f(0.2-6 kev) (erg cm Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 4 / 34
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
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
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
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
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 E max 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
Astrophysical sources Centaurus A Results for acceleration close to the core: α =1.2 log 10 (E 2 Φ/eV km -2 yr -1 ) 18 17 16 15 C G R O FERM I H E S S γ total ne utrinos initia l protons P AO fina l protons 14 γ 13 8 10 12 14 16 18 20 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 7 / 34
Astrophysical sources Centaurus A Results for acceleration close to the core: α =2 19 log 10 (E 2 Φ/eV km -2 yr -1 ) 18 17 16 15 C G R O FERM I initia l protons fina l protons H E S S γ P AO total ne utrinos promising test case for HESS / FERMI γ γ-ray spectrum rather insensitive to α 14 8 10 12 14 16 18 20 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 7 / 34
Astrophysical sources HESS observations of Cen A Centaurus A no variability Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 8 / 34
Astrophysical sources HESS observations of Cen A Centaurus A no variability consistent with point source Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 8 / 34
Astrophysical sources HESS observations of Cen A Centaurus 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
Astrophysical sources Centaurus A Comparison to recent HESS and FERMI observations log 10 (E 2 Φ/eV km -2 yr -1 ) 20 19 18 17 16 broken Fermi initial protons final protons α=2 P AO H E S S α=1.2 15 γ γ 14 8 1 0 1 2 1 4 1 6 1 8 2 0 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 9 / 34
Astrophysical sources Centaurus A Comparison to recent HESS and FERMI observations log 10 (E 2 Φ/eV km -2 yr -1 ) 20 19 18 17 16 15 broken Fermi shape and normalization okay TeV γ-ray and neutrino source initial protons final protons α=2 P AO H E S S α=1.2 γ γ 14 8 1 0 1 2 1 4 1 6 1 8 2 0 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 9 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: a) (isotropic) source injection spectrum F γ (E) 1/E 2 E 2 F(E ) 10 12 14 16 18 20 log10(e /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 10 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: a) (isotropic) source : thin above 10 16 ev, ultra-rel. regime E 2 F(E ) E γε γ m 2 e 10 12 14 16 18 20 log10(e /ev ) ultra-rel. regime Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 10 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: b) on EBL photons above 10 14 ev cascade on EBL E 2 F(E ) 10 12 14 16 18 20 log10(e /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 11 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: b) on EBL photons above 10 14 ev cascade on EBL : fill up GeV TeV range E 2 F(E ) 10 12 14 16 18 20 log10(e /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 11 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: b) on EBL photons above 10 14 ev cascade on EBL : fill up GeV TeV range E 2 F(E ) main criteria: L UHE, not shape evidence for acceleration to UHECRs? however: anisotropic UV field complicates picture already in source 10 12 14 16 18 20 log10(e /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 11 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: collinear regime log 10 τ γγ 4 3 2 1 0-1 -2-3 isotropic anisotropic -4 8 1 0 1 2 1 4 1 6 1 8 2 0 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 12 / 34
Astrophysical sources Electromagnetic cascades in the source Regenerating TeV photons: decaying muons log 10 (l/pc) 2 1 0-1 -2-3 -4-5 R 1 l int, U V l int, IR no cutoff l dec,µ l int, IR cutoff -6 12 13 14 15 16 17 18 19 20 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 13 / 34
Astrophysical sources Regenerating TeV photons: log 10 (l/pc) 2 1 0-1 -2-3 -4-5 R 1 l int, U V Electromagnetic cascades in the source adding IR l int, IR no cutoff l dec,µ l int, IR cutoff -6 12 13 14 15 16 17 18 19 20 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 13 / 34
Astrophysical sources adding IR from a compact source: Electromagnetic cascades in the source log 10 (E 2 Φ/eV km -2 yr -1 ) 20 19 18 17 Fermi E max = 10 20 ev E max = 10 19 ev E max = 10 18 ev H E S S 16 R IR = 1 pc 15 8 9 1 0 1 1 1 2 1 3 1 4 1 5 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 14 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos Photon and neutrino production relatively tight connected: protons: p + γ3k { p + π 0 p + 2γ n + π + p + 2e ± +4ν Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 15 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos Photon and neutrino production relatively tight connected: protons: p + γ3k { p + π 0 p +2γ n + π + p +2e ± +4ν nuclei: A + γ3k (A 1) + n (A 1) + p + e + ν e connection to UHECRs looser Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 15 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos Photon and neutrino production relatively tight connected: protons: p + γ3k { p + π 0 p +2γ n + π + p +2e ± +4ν nuclei: A + γ3k (A 1) + n (A 1) + p + e + ν e 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
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos Photon and neutrino production relatively tight connected: protons: p + γ3k { p + π 0 p +2γ n + π + p +2e ± +4ν nuclei: A + γ3k (A 1) + n (A 1) + p + e + ν e cascade limit: [Berezinsky, Smirnov 75 ] all energy in γ and e ± cascades below 100 GeV K(E/ε X ) 3/2 at E ε X J γ (E) = K(E/ε X ) 2 at ε X E 0 at E > ε a Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 15 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos Photon and neutrino production relatively tight connected: protons: p + γ3k { p + π 0 p +2γ n + π + p +2e ± +4ν nuclei: A + γ3k (A 1) + n (A 1) + p + e + ν e cascade limit: all energy in γ and e ± cascades below 100 GeV [Berezinsky, Smirnov 75 ] Fermi-LAT measurement of EGRB: ω cas > 4π de EI ν (E) 4π c E 0 c E 0I ν (>E 0 ) < 6 10 7 ev/cm 3 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 15 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Comparison of Monte Carlo and analytical estimate 1e+15 100M pc E -3/2 1e+14 E 2 *J(E ) 1e+13 1e+12 1e+11 1e+06 1e+07 1e+08 1e+09 1e+10 1e+11 1e+12 1e+13 1e+14 1e+15 E /ev Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 16 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Comparison of Monte Carlo and analytical estimate 1e+15 100M pc 1000M pc E -3/2 E -1.9 1e+14 E 2 *J(E ) 1e+13 1e+12 1e+11 1e+06 1e+07 1e+08 1e+09 1e+10 1e+11 1e+12 1e+13 1e+14 1e+15 E /ev Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 16 / 34
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
Cosmogenic fluxes Neutrino limits from the EGRB Fermi-LAT vs. UHECR data: [Berezinsky et al. 10 ] integrating EJ(E) gives bound ω cas < 6 10 7 ev/cm 3 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 17 / 34
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
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos [Ahlers et al. 10 ] E min = 10 19 ev HiRes (3 x ) RICE ( e,µ, ) BAIKAL ( e,µ, ) Auger (3 ) AMANDA (3 µ) AMANDA ( e,µ, ) ANITA ( e,µ, ) IceCube (5, 1yr) 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 E [GeV] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 18 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos MainEdifference: min = 10 19 evexpected IceCube sensitivity end of exp. sensitivity for 1/E 2 flux: 10 17 vs. 10 19 ev overall sensitivity of IceCube HiRes (3 x ) RICE ( e,µ, ) BAIKAL ( e,µ, ) Auger (3 ) AMANDA (3 µ) AMANDA ( e,µ, ) ANITA ( e,µ, ) IceCube (5, 1yr) 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 E [GeV] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 18 / 34
Cosmogenic fluxes Neutrino limits from the EGRB Cascade limit for cosmogenic neutrinos MainEdifference: min = 10 19 evexpected IceCube sensitivity end of exp. sensitivity for 1/E 2 flux: 10 17 vs. 10 19 ev overall sensitivity of IceCube HiRes (3 x ) RICE ( e,µ, ) BAIKAL ( e,µ, ) Auger (3 ) AMANDA (3 µ) AMANDA ( e,µ, ) ANITA ( e,µ, ) All plots for proton primaries IceCube (5, 1yr) for nuclei reduced neutrino fluxes... 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13 10 14 E [GeV] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 18 / 34
Cosmogenic fluxes Diffuse photons Cosmogenic photons [Hooper, Taylor, Sarkar 10 ] photon fra ction 10 0 10-1 10-2 10-3 10-4 10-5 10-6 E max,z =(Z/26)x10 21 ev α=2.0 B<3 pg P rotons Iron 1 8.2 1 8.4 1 8.6 1 8.8 1 9 1 9.2 1 9.4 1 9.6 1 9.8 2 0 log 10 E nergy [ev ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 19 / 34
Cosmogenic fluxes Diffuse photons Cosmogenic photons [Hooper, Taylor, Sarkar 10 ] photon fraction 10 0 10-1 10-2 10-3 10-4 10-5 10-6 E max,z =(Z/26)x10 21 ev α=2.0 B<3 pg P rotons Iron 18.2 18.4 18.6 18.8 19 19.2 19.4 19.6 19.8 20 log 10 E nergy [ev ] A>1: photons suppressed by factor 10 compared to protons even proton: requires sensitivity improved by 100 large E max and small α helps... Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 19 / 34
Cosmogenic fluxes Diffuse photons Cosmogenic photons [Hooper, Taylor, Sarkar 10 ] photon fra ction 10 0 10-1 10-2 10-3 10-4 10-5 E max,z =(Z/26)x10 22 ev α=2.0 B<3 pg P rotons Iron 10-6 1 8.2 1 8.4 1 8.6 1 8.8 1 9 1 9.2 1 9.4 1 9.6 1 9.8 2 0 log 10 E nergy [ev ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 19 / 34
Cosmogenic fluxes Diffuse photons Cosmogenic photons: dependence on α [Gelmini, Kalashev, Semikoz 05 ] 100 10 j(e ) E 2 [ev cm -2 s -1 sr -1 ] 1 0.1 1.5 2.0 2.0 1.5 0.01 2.7 2.7 0.001 1e+19 1e+20 1e+21 E [ev ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 20 / 34
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 ] 10000 1000 protons E max =10 20 ev E max =10 21 ev Auger data (2007) R ate (>E ) [yr -1 ] 100 10 1 0.1 0.01 photons S ource at 3.8 M pc α=2 0.001 0.0001 18 18.5 19 19.5 20 20.5 21 21.5 22 log 10 E [ev ] Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 21 / 34
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
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 2 10 1 10 8 G ev 10 10 G ev 10 11 G ev 10 0 E 2 dn /de, ev cm -2 s -1 10-1 10-2 10-3 10-4 10-5 10-6 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 E, G ev Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 21 / 34
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 2 10 1 10 8 G ev 10 10 G ev 10 11 G ev 10 0 E 2 dn /de, ev cm -2 s -1 10-1 10-2 10-3 10-4 10-5 10-6 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 E, G ev large luminosities Leff 10 47 10 49 erg/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
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
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
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
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, Völk 94: Pair halos around AGNs Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 22 / 34
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, Völk 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
Gamma-rays and the EGMF Observer misaligned with jet: [Neronov et al. 10 ] e + e e+ e O jet 0 obs O ext probability for misalignement p ϑ obs most blazars viewed with ϑ obs ϑ jet Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 23 / 34
Gamma-rays and the EGMF Observer misaligned with jet: [Neronov et al. 10 ] e + e e+ e O jet 0 obs O ext probability for misalignement p ϑ obs most blazars viewed with ϑ obs ϑ jet halos are not symmetric Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 23 / 34
Gamma-rays and the EGMF Observer misaligned with jet: [Neronov et al. 10 ] e + e e+ e O jet 0 obs O ext probability for misalignement p ϑ obs most blazars viewed with ϑ obs ϑ jet halos are not symmetric time-delay is function of ϑ, [ ][ ] T delay (ϑ) 3 10 6 (ϑobs +Θ jet ) ϑ yr 5 5 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 23 / 34
Gamma-rays and the EGMF Asymmetric halos around TeV blazars ( GeV jets ): 0.001 0.01 0.1 1 ϑ obs =0 ϑ obs =3 ϑ obs =6 ϑ obs =9 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 24 / 34
Gamma-rays and the EGMF GeV jets : B dependence 0.001 0.01 0.1 10 17 G 10 16 G 10 15 G 10 14 G 1 Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 25 / 34
Gamma-rays and the EGMF GeV jets : time dependence of flares 0.001 0.01 0.1 1 0 <T delay < 10 5 yr 3 10 6 yr< T delay < 10 7 yr Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 26 / 34
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
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
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
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 ϑ jet Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 28 / 34
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 ϑ jet 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
Gamma-rays and the EGMF Lower limit on EGMF: [MK, Ostapchenko, Tomàs ] log 10 (E 2 F/erg cm -2 s -1 ) -11-12 -13-14 Fermi 10-16 G 10-15 G 5 10-15 G 10-14 G 5 10-14 G H E S S 7 8 9 10 11 12 13 14 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 29 / 34
Gamma-rays and the EGMF Lower limit on filling factor: [MK, Ostapchenko, Tomàs 10 ] model filaments by a top-hat: B = 10 10 G B =0 10 Mpc Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 30 / 34
Gamma-rays and the EGMF Lower limit on filling factor: [MK, Ostapchenko, Tomàs 10 ] log 10 (E 2 F/erg cm -2 s -1 ) -11-12 -13-14 Fermi 0.10 0.25 0.50 0.75 0.90 H E S S 7 8 9 10 11 12 13 14 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 31 / 34
Gamma-rays and the EGMF Lower limit on filling factor: [MK, Ostapchenko, Tomàs 10 ] log 10 (E 2 F/erg cm -2 s -1 ) -11-12 linear filling factor > 50% Fermi H E S S 0.10-13 0.25 mainly 3-step cascade: γ e ± γ 0.50 photon mean free path D γ (E) 1000 50 0.75 Mpc 0.90 electron mean free path D e (E) few kpc -14 7 8 9 10 11 12 13 14 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 31 / 34
Gamma-rays and the EGMF Lower limit on filling factor: [MK, Ostapchenko, Tomàs 10 ] log 10 (E 2 F/erg cm -2 s -1 ) -11-12 linear filling factor > 50% Fermi H E S S 0.10-13 0.25 mainly 3-step cascade: γ e ± γ 0.50 photon mean free path D γ (E) 1000 50 0.75 Mpc 0.90 electron mean free path D e (E) few kpc -14 electrons are created everywhere and feel B only close to interaction point 7 8 9 10 11 12 13 14 log 10 (E /ev ) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 31 / 34
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
Gamma-rays and the EGMF EGMF in voids already observed? [Ando, Kusenko 10 ] stack 170 brightest AGN search for excess over PSF Rel. DEC (deg) C ounts M ap (3-10 G ev ) Rel DEC (deg) M odel M ap (3-10 G ev ) 0.5 0.5 0 0-0.5-0.5 0.5 0 Rel. RA (deg) 359.5 0.5 0 R el R A (deg) 359.5 10 20 30 40 50 60 (counts) 10 20 30 40 50 (counts) Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 32 / 34
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
Gamma-rays and the EGMF EGMF in voids already observed? [Ando, Kusenko 10 ] stack 170 brightest AGN search for excess over PSF Rel. DEC (deg) Counts Map (3-10 GeV ) Rel DEC (deg) M odel M ap (3-10 G ev ) 0.5 0.5 0 0-0.5-0.5 0.5 0 359.5 0.5 0 359.5 Rel. RA (deg) R el R A (deg) 10 20 30 40 50 60 (counts) 10 20 30 40 50 (counts) explained by B 10 15 G(λ B /1 kpc) 1/2 and λ B < 10 100 kpc Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 32 / 34
Gamma-rays and the EGMF EGMF in voids already observed? [Ando, Kusenko 10 ] stack 170 brightest AGN search for excess over PSF Rel. DEC (deg) Counts Map (3-10 GeV ) Rel DEC (deg) M odel M ap (3-10 G ev ) 0.5 0.5 0 0-0.5-0.5 0.5 0 359.5 0.5 0 359.5 Rel. RA (deg) R el R A (deg) 10 20 30 40 50 60 (counts) 10 20 30 40 50 (counts) lower limit B > 5 10 15 G requires λ B < 0.1 kpc Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics 10 32 / 34
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
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
Summary Gamma-rays and the EGMF 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
Summary Gamma-rays and the EGMF 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
Summary Gamma-rays and the EGMF 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
Summary Gamma-rays and the EGMF 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