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

Gamma-rays from CR sources Michael Kachelrieß NTNU, Trondheim []

TeV gamma-rays from UHECR sources 22 radio 20 18 log10(E/eV) photon horizon γγ → e + e − 16 CMB 14 IR 12 Virgo ⇓ 10 kpc 10kpc 100kpc M pc 10M pc 100M pc Gpc 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 ∼ τ ˙ n 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 ∼ τ ˙ n 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 -12 × 10 Feb. 2005 March 2005 April 2005 May 2005 6 ) -1 s -2 (E>730GeV) (cm 4 2 Φ 0 09/Feb 16/Feb 09/Mar 16/Mar 30/Mar 06/Apr 04/May 11/May Date B -12 -12 10 10 × × ) -1 s 2005 H.E.S.S. -2 1.5 ) f(0.2-6 keV) (erg cm -1 s 40 average -2 (E>730GeV) (cm HEGRA 1.0 2003 Chandra (HST-1) Chandra (nucleus) 20 0.5 2006 Φ 2004 0.0 0 12/1998 12/2000 12/2002 12/2004 12/2006 Date Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 4 / 34

HESS observations of M87: A -12 × 10 Feb. 2005 March 2005 April 2005 May 2005 6 ) -1 s -2 (E>730GeV) (cm 4 2 Φ 0 09/Feb 16/Feb 09/Mar 16/Mar 30/Mar 06/Apr 04/May 11/May Date B -12 -12 × 10 × 10 ) -1 s 2005 H.E.S.S. -2 1.5 ) f(0.2-6 keV) (erg cm -1 fast variability excludes acceleration along kpc jet s average 40 -2 (E>730GeV) (cm HEGRA acceleration in hot spots marginally okay 1.0 2003 Chandra (HST-1) 20 Chandra (nucleus) favors acceleration close to SMBH 0.5 Φ 2006 2004 0.0 0 12/1998 12/2000 12/2002 12/2004 12/2006 Date Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 4 / 34

HESS & Veritas observations of M87: A -12 × 10 Feb. 2005 March 2005 April 2005 May 2005 6 ) -1 s -2 (E>730GeV) (cm 4 2 Φ 0 09/Feb 16/Feb 09/Mar 16/Mar 30/Mar 06/Apr 04/May 11/May Date B -12 -12 × 10 × 10 ) -1 s 2005 H.E.S.S. -2 1.5 ) f(0.2-6 keV) (erg cm -1 fast variability excludes acceleration along kpc jet s average 40 -2 (E>730GeV) (cm HEGRA acceleration in hot spots marginally okay 1.0 2003 Chandra (HST-1) 20 Chandra (nucleus) favors acceleration close to SMBH 0.5 Φ 2006 2004 0.0 0 12/1998 12/2000 12/2002 12/2004 12/2006 Date 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 initial CGRO HESS protons 17 PAO total neutrinos FERMI 16 final protons γ 15 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 ) initial protons CGRO 18 final protons PAO HESS 17 total FERMI 16 neutrinos γ 15 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 Centaurus A HESS observations of Cen A no variability Michael Kachelrieß (NTNU Trondheim) Gamma-rays from CR sources TeV Particle Astrophysics ’10 8 / 34

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

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

Astrophysical sources Centaurus A Comparison to recent HESS and FERMI observations 20 log 10 (E 2 Φ /eV km -2 yr -1 ) initial protons broken 19 final protons Fermi 18 α =2 PAO 17 HESS 16 α =1.2 γ 15 γ 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 9 / 34

Astrophysical sources Centaurus A Comparison to recent HESS and FERMI observations 20 log 10 (E 2 Φ /eV km -2 yr -1 ) initial protons broken 19 final protons Fermi 18 α =2 PAO 17 HESS 16 α =1.2 γ 15 shape and normalization okay γ TeV γ -ray and neutrino source 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 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) ultra-rel. regime E γ ε γ m 2 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: 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