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Neutrinos, AGN and Auger data

ANTARES Meeting

December 5th, 2007

Nicolas Busca, APC

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Scope

• Auger found a correlation of CR with nearby AGN

• The UHECR flux at Earth is ~ 1 event/yr/1000km2

• Use this flux to normalize the

• Will only consider interactions of CR with the AGN photon background

• Results will refer to point source fluxes (diffuse flux study in progress…)

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Review of Auger results

Analysis:

• Before May 26th 2006 - explorationFound 12/15 events in correlation with a VC AGN by scanning for the best combination of angle, energy and redshift

(3.10, Emin = 56EeV, zmax=0.018)

• Prescription

• After May 26th 2006 - confirmationFound 8/13 events in correlation with a VC AGN with parameters fixed a priori

Results:After rescanning, the parameters were found to be ~ 60,

Emin~60 EeV, zmax~0.024 (100 Mpc)

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Review of Auger results

AGN correlation

• 21 events of E>57EeV (outside the galactic plane)

• 19 within 3.20 of a VC AGN with z<0.018 (75 Mpc)

Super galactic plane

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Review of Auger results

AGN correlation

• 21 events of E>57EeV

• 19 within 3.20 of a VC AGN with z<0.018 (75 Mpc)

Virgo clusterSuper galactic plane

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Review of Auger results

AGN correlation

• 21 events of E>57EeV

• 19 within 3.20 of a VC AGN with z<0.018 (75 Mpc)

2 events (ESO 139 G12, 73 Mpc)

Super galactic plane

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Review of Auger results

AGN correlation

• 21 events of E>57EeV

• 19 within 3.20 of a VC AGN with z<0.018 (75 Mpc)

2 events (Cen A, 4 Mpc)Super galactic plane

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Review of Auger results

What does this mean?

• CRs are anisotropic

• CRs come preferentially from the direction of some VC AGN

But…

• are AGN really the sources?

• do CR sources have the same distribution as VC AGNs?

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Review of Auger results

What does this mean?

• CRs are anisotropic

• CRs come preferentially from the direction of some VC AGN

But…

• are AGN really the sources?

• do CR sources have the same distribution as VC AGNs?

CRs traverse the environment of an AGN before reaching us!!

(and produce neutrinos…)

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Implications for ’s

nucleus

CR

Production modes:

• foreign (to the AGN)

foreign

• CRs are accelerated away from the nucleus

• AGN need not be the source

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Implications for ’s

nucleus

CR

Production modes:

• foreign (to the AGN)

• local

nucleus

CR

foreign local

• CRs are accelerated away from the nucleus

• AGN need not be the source

• CRs are accelerated near the core of the AGN

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Implications for ’s

nucleus

CR

Production modes:

• foreign (to the AGN)

• local

nucleus

CR

foreign local

• CRs are accelerated away from the nucleus

• AGN need not be the source

• CRs are accelerated near the core of the AGN

€

p+ γ → π 0 + p

p+ γ → π + + n+ isospin symmetric interactions

Interactions:

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CR propagation in AGNs

R ~ 30 Rs ~ 6x1012 cm ~ 2x10-12 Mpc

R

Foreign:

• CR traverse Leff = R

• is a free parameter

Local:

• CRs traverse exactly R

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Photon background (Cen A)

AGN photon background

Steinle (2006)

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AGN photon background

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Proton interaction length

Cen A model

Stecker (1991)

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Proton interaction length

Cen A model

Stecker (1991)

thick

thick

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Spectrum normalization

Cen A

ESO 139 G12

• same exposure to both sources

• same flux at Earth

• but very different luminosity since DCenA ~ 4Mpc and DESO ~ 75 Mpc

• ’s normalized together with the spectrum

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Results: local mode

• source optically thick above the photopion threshold

• no UHECRs would be observed from the source

• model is excluded

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Results: foreign mode, = 1e-3

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Results: foreign mode, = 6e-4

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Results: foreign mode, = 3e-4

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Results: foreign mode, = 1e-4

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Results: foreign mode, = 1e-4

Evolution with spectral index ~ 10x each 0.2

(2.0 is 105 x less than 2.7)