Sensitivity of the neutrino telescope Antares to the diffuse galactic neutrinos flux

1. Sensitivity of the neutrino telescope Antares to the diffuse galactic neutrinos flux Fabrice Jouvenot Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

2. Stable Neutral Weak interaction cross section The neutrino, an astroparticle Neutrino Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

3. The Sky Near infrared COBE / DIRBE Infrared COBE / DIRBE Photomosaic - Lausten et al. Gamma rays Visible Neutrinos Radio waves X-rays 0.25, 0.75, 1.5 keV – ROSAT / PSPC 21,1 cm - Dwingeloo >100 MeV – CGRO / EGRET ? ANTARES ? Milky Way Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

4. The Galaxy Halo Sun Ring + bar Galactic center Bulge Spiral arms Galactic plane ~ 1 kpc 8,5 kpc 15 – 20 kpc 1 pc = 3,3 light years Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

5. Proton ~ 90 % Atomic Hydrogen HI Lyman α, and 21cm absorption Molecular Hydrogen H2 2.6 mm emission from the CO rotation Ionized Hydrogen HII MHD models, pulsar observations Helium He Energy density, eV cm-3 Alpha ~ 9 % 91 % number 71 % mass 9 % number 28 % mass Density [atoms cm-3] R, kpc Mean density: 1 proton per cm3 Heavy Nucleus ~ 1 % In the galactic plane Stars Galactoradius [kpc] TOTAL Dust CMB Inside the Galaxy • Compact objets • Interstellar Matter • Interstellar radiation field • Magnetic field • Galatic wind • Cosmic rays Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

6. Theorical hypothesis Propagation Electromagnetic Interactions Nuclear physics Cosmic Rays Magnetic Field Interstellar Matter On Earth Propagation of Cosmic-Rays Equilibrium between CR, B et ISM. • Energy losses • Diffusion on magnetic field and galactic winds • Reacceleration • Decay • Nuclear reaction Observables Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

7. Sources distributions Creation of the Galaxy (ISM, isrf, …) Cosmic-Rays and sources Propagation of the heaviest nucleus to the lightest • Cylindrical galactocentric geometry: • R (0 – 30 kpc) • z (-4 – 4 kpc) Secondary products and decays Cosmic-rays, electrons/positrons, antiprotons, photons. Neutrinos production (νμ, νμ, νe, νefrom charged pions decays) ) GalpropSimulation of Cosmic-Rays confinment Reading parameters and data (cross-sections, branching ratio, …) Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

8. Process creating π in p-p collisions • (Δresonance & multi pion production) • Integral over the CR spectrum and ISM density. Neutrinos production • Process giving a neutrino with energy Eν. • (Charged pions decays • → Energy range of the pion (2 body or 3body decay)). • Neutrino Oscillation νe:νμ:ντ • 1:2:0 → 1:1:1 Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

9. Inverse Compton Inverse Compton Inverse Compton Bremsstrahlung Bremsstrahlung Bremsstrahlung Orion arm Toward the galactic center Toward the galactic center Sun Sun 500 pc 500 pc Models Hard Nucleus HN Conventional C Observations Hard Electron HEMN E2 x Intensity [MeV cm-2 s-1 sr-1 ] Energy [MeV] Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

10. E2 x Neutrino flux [particles MeV s-1 cm-2] E2 x Neutrino flux [particles MeV s-1 cm-2] Energy [MeV] Energy [MeV] νμ+νμon Earth Antares HN model Flux distribution (arbitrary unit) Flux distribution (arbitrary unit) HE model C model -90° 0° 90° -180° 0° 180° HEMN model Galactic latitude Galactic longitude γ = 2,3 à 2,9 E2 x Neutrino flux [particles MeV s-1 cm-2] Energy [MeV] Galactic emission Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

11. Detection Principle Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

12. Michel Pacha Institut La Seyne-sur-Mer Undersea cable Antares -2475m A bit of geography Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

13. The detector • 12 lines of 75 PM • 5 sectors / line • 5 storeys / sector • 3 PM / storeys 350 m Cable 40 km 2475 m 14,5 m 100 m Junction box 60 m – 70 m Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

14. Atmospheric Environmental Atmospheric neutrinos Atmospheric muons Potassium decay Bioluminescence 40K → 40Ca + e- +νe Counting rate [kHz] Time [s] Background Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

15. ANTARES 43o North : Galactic centre observed 2/3 of the time AMANDA South pole View of the sky • Instant view : 2 π sr • Integrated view for a day : 3,5 π sr Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

16. Angular resolution Angular resolution [°] Effective area for muons Effective area [km2] Angle between the neutrino and the reconstructed muon <1 degree Antares response function Logarithm of the reconstructed energy of the muon [GeV] Spectral indices 2.4 2.7 3.7 Number of events Logarithm of the true energy of the muon [GeV] Log of the muon energy [GeV] Reconstruction • Track reconstruction • → Detector answer • → Angular resolution • Energy reconstruction Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

17. Galactic emission Flux simulation : 1 MeV – 107 GeV Neutrinos Working files Atmospheric Isotropic Monte Carlo simulation Energy: 10 GeV – 107 GeV 95x1010 νμ 110x1010νμ 5 millions induces muons (at least 1 PM fired) Energy: 10 GeV – 107 GeV Monte Carlo Simulation Atmospheric muons Earth rotation Galactic & atmospheric ponderation Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

18. Signal Background Result of the simulation Atmospheric neutrinos : ~ 20 000 Atmospheric muons : ~ 30 000 000 Upgoing muons per year for the whole sky, E> 10 GeV Galactic neutrinos : ~ 1 to 40 Upgoing muons per year for the whole sky, E> 10 GeV Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

19. Energy Angular cut Log10 (number of events per year) Galactic neutrinos Galactic longitude [°] 0,03 Atmospheric neutrinos 0,02 0,01 Cut on the quality 0 200 300 100 % of the number of events per year Atmospheric muons 0,2 33 millions upgoing reconstructed muons per year Multiplicity: 4,4 Distance between muons: 15 m 0,1 Atmospheric neutrinos 0 0 90 -90 Galactic latitude [°] Signal extraction Reconstruction quality Atmospheric muons < 10% atm. neutrinos above 10 TeV Galactic latitude Galactic longitude Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

20. years years Calculus principle years years years years Detection probability observed estimated Probability (Nobs > Nl) < 1% If there’s only background Detection probability Cut on log of the reconstructed energy log[GeV] Detection probability Detection probability Getting probability b Detection probability b+s Nl Number of events Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

21. Detection probability vs observation time (99% CL) 1 Performances Antares – 5 years It is not possible to observe the Galaxy in a reasonable time Antares – 10 years 0,5 Detection probability 0 1 10 100 1000 Number of years of running A kilometric detector is needed ! Antares sensitivity Limit on the model, γ = 2,3 Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

22. The HN model is observable. Kilometric extrapolation Example of a km3 detector • Sensitivity Homogenous cube 20 x 20 x 20 PM looking downward Effective area ~ 40 × Antares (2 km²) Cost ~ 5 × Antares Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

23. Shape identification Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

24. Galactic doubt Modelisation Dark clouds Environment Detector Bilan Site choice Depth Latitude Energie reconstruction Effective area Other neutrinos flavours Galactic fluxes have been calculated Answer of neutrino telescopes Antares: limits on the HN model. KM3: detection or limits on HN. Conclusions Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

26. Kilometric telescopes • 2005  Ice Cube • 2006  KM3Net Toward the kilometre cube… • 1996 – 2000  Tests • 2001-2003  Study of feasibility • 2005 – 2007  Construction & deployment Antares Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

27. Shape identification Working area Map Pixel Shape identification Probability calculation Max proba pixel ? ? ? Scan nearest pixels ? ! ? Selection max proba ? ? ? Extension of the sélection Decrease the pixel size Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

28. Nuclei Electrons & positrons Contraints Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion

29. protons g g Stable Neutral Weak interaction cross section E < 1019 eV deviated by magnetic fields Short mean free path E > 1020 eV → GZKeffect Short mean free path 1 TeV → 700 Mpc 1 PeV → 15 kpc Libre parcours moyen due to the interaction with the different photons backgrounds Libre parcours moyen dû à l’interaction avec les différents fonds de photons Astroparticles Photon Noyaux Neutrino Galactic Neutrinos Introduction The Galaxy ANTARES Sensitivity Km3 Conclusion