1. c Alexander Kappes for the IceCube Collaboration 23 rd European Cosmic-Ray Symposium Moscow, 7. July 2012 Neutrino astronomy with the IceCube Observatory

2. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 2 Outline ‣ Introduction and IceCube performance ‣ Diffuse neutrino fluxes at medium and high energies ‣ Point-like sources and Gamma-Ray Bursts ‣ Other physics covered by IceCube

3. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 3 Messengers of the high-energy universe p π ± + X μ + ν μ e + ν μ + ν e → γ ν p,e p + p(γ): π 0 + X γ + γ → e + γ (Inverse Compton): e + γ → source e

4. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 4 Transform natural abundance of transparent medium (ice, water) into a particle detector muon νμνμ nuclear reaction cascade Time & position of hits μ (~ ν) trajectory Energy PMT amplitudes Neutrino detection principle

5. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 5 Neutrino signatures Track-like: ‣ Source: ν μ CC interaction ‣ Good angular resolution (< 1°) ‣ Sensitive volume ≫ instrumented volume Cascade-like: ‣ Source: ν e, ν μ, ν τ NC + ν e CC interaction ‣ Good energy resolution (few 10%) ‣ Bad angular resolution ( > O(10°) ) ‣ Sensitive volume ≈ instrumented volume Composites: ‣ Source: ν τ CC & ν μ CC inside instrumented volume ‣ Challenging to reconstruct muon (IceCube) cascade (IceCube)

6. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 6 Atmospheric muons and neutrinos p atmosphere cosmic rays μ νμνμ νμνμ cosmic p μ νμνμ Muons detected year -1 (IceCube) ‣ atmospheric*μ7×10 10 ‣ atmospheric**ν→μ5×10 4 ‣ astrophys (expct)ν→μO(10) * 2000 per second ** 1 every 6 minutes

7. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 7 Neutrino telescope projects IceCube BaikalBaikal ANTARESANTARES Text KM3NeT (preparation phase) KM3NeT

8. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 8 -1450 m -2450 m The IceCube observatory Completed since Dec. 2010 ‣ IceTop Air shower detector ‣ InIce 86 strings (5160 PMTs) Instrumented volume: 1 km 3 ‣ Deep Core densely instrumented central region (8 strings) → see talk by H. Kolanoski

9. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 9 Detector history and status StringsYearLivetime Trigger rate (Hz) HE ν rate (per day) AMANDA II (19) 2000−20063.8 years100~5 / day IC402008/09375 days1100~40 / day IC592009/10350 days1900~70 / day IC792010/11320 days2250~100 / day IC86−I2011/12~ 340 days2700processing IC86−IIcurrent2700data taking ‣ IC86 uptime typical 99% (only 2% failed DOMs) ‣ Detector sensitivity increases faster than # strings

10. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 10 Atmospheric neutrinos ‣ High statistics sample ~ 50.000 per year ‣ Prompt component still unknown ‣ Both signal and background (IC40) Waxman&Bahcall bound astrophysical neutrinos

11. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 11 Cosmic diffuse neutrino fluxes ‣ Search for excess in high energy tail ‣ Requires knowledge of prompt component atm. ν cosmic ν (E -2 ) W&B bound Cosmogenic neutrinos: p + CMB → n + π + ↳ μ + + ν μ IC59

12. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 12 Cosmogenic neutrinos (IC79+86-I) Optimized cuts for UHE neutrinos: ‣ Expected background = 0.14 (without prompt) ‣ Observed = 2 (p-value 2.3σ) Jan 3, 2012 Aug. 9, 2011 IC86-I log 10 NPE (energy proxy) # events within livetime preliminary background (no prompt) predictions prompt

13. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 13 Sensitivity UHE neutrinos (IC79+86-I) ‣ Closing in on predictions ‣ No significant excess so far ‣ Substantial improvements in analysis anticipated Stay tuned!

14. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 14 Skymap events (IC40+59) ‣ IceCube is an all-sky telescope ‣ Main sensitivity to sources in the northern sky 14 Northern hemisphere 58,000 events 87,000 events Southern hemisphere atm. muons PeV − EeV atm. neutrinos TeV − PeV equatorial coordinates preliminary

15. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 15 Point sources: Significance skymap (IC40+59) 15 preliminary 67% atm. muons PeV − EeV atm. neutrinos TeV − PeV

16. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 16 Point sources: Selected sources (IC40+59) preliminary ‣ 13 Galactic SNRs..., 30 extragalactic AGNs ‣ No significant excess (both all-sky and source list) up to now ‣ Unblinding of IC79 data soon

17. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 17 Point sources: Sensitivities & upper limits 90% CL sensitivity / upper limits for E -2 spectrum ANTARES IceCube KM3NeT discovery region Galactic γ-ray sources Galactic Center MACRO

18. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 18 Gamma-ray bursts (GRBs) ‣ Short, very intense flashes of γ radiation (keV-MeV) ‣ Ejected material has Γ ≳ 300 ‣ One of few candidate sources for UHECRs e p n + π + p + π 0 γ (PeV) ν (PeV) internal shocks collapse γ (MeV) Fireball model 10100 Energy [keV] E 2 × flux [keV cm -2 s -1 ] 10 100 1000 1 GRB030329 10 4

19. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 19 GRBs with IceCube ‣ Using satellite information (time and direction, GCN) very low background → 1 event can be significant ! ‣ Observed busts (northern sky) -IceCube 40: 117 -IceCube 59: 98 ‣ Individual modeling of neutrino fluxes (fireball model) On-time (blind)Off-time T0T0 prompt precursor (~100 s) model independent (several hours) background IC59: 98 bursts in northern sky 1 TeV100 TeV10 PeV Waxman&Bahcall Sum of 98 bursts flux

20. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 20 GRBs: IceCube results (IC40+59) Observed = 0 Expected = 8.4 prediction 90% UL ×3.7 E 2 × flux [GeV cm -2 s -1 sr -1 ] allowed neutrino break energy [GeV] high Γlow Γ Are GRBs the sources of UHECRs? Nature Vol. 484, 351 (2012)

21. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 21 Conclusions from GRB analyses ‣ Where are the neutrinos? -GRBs not origin of UHECRs ? (according to some models) -Physics modeling not sufficient ? (models are being revisited → significant flux reductions) ‣ Unblinding of IC86-I soon ‣ Going near real-time with GRBs in future Waiting for neutrinos from GRBs !

22. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 22 Cosmic rays Physics spectrum with IceCube Cosmic accelerators Diffuse fluxes Dark Matter & Exotic Physics Supernovae Neutrino Properties & Particle Physics → see H. Kolanoski’s talk Point-like sources (SNRs, Binaries...) Transient sources (GRBs, AGN flares...) Extended sources All-sky fluxes (e.g. cosmogenic) Galactic plane Extended structures (e.g. Fermi-Bubbles) Indirect DM search (Sun, Galactic halo) Magnetic monopoles, Q-balls Lorentz invariance violation Spectrum around “knee” (10 15 −10 17 eV) Composition Anisotropy Galactic/LMC SNe SN phases Neutrino hierarchy Charm in showers Neutrino oscillations K/π ratio in showers Cross sections at very high energies

23. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 23 DeepCore Dust layer First steps into ν oscillations DeepCore: ‣ Decreases energy threshold to ~10 GeV ‣ Look for standard oscillations ‣ Strategy: Simple cuts and reconstructions Top View ν μ disappearance 0°-45° DeepCore low energy IceCube high energy 1 GeV 10 GeV 100 GeV -90° minimum Θ=0° Θ=-90° 12,000 km DeepCore low energyIceCube high energy Θ=0°Θ=-90° Θ=0° systematics cos(90°-Θ)

24. Alexander Kappes, ECRS’12, Moscow, 7. July 2012c 24 Summary and Outlook ‣ IceCube detector completed since 1 1/2 years; provides unprecedented amount of high-quality data ‣ IceCube is a multi-purpose observatory (neutrino astronomy, dark matter, SNe, cosmic-rays, particle physics...) ‣ Neutrino astronomy: -finally reaching sensitivity of astrophysical significance (GRBs, cosmogenic neutrinos, Waxman&Bahcall bound) -discovery of first cosmic neutrinos might be around the corner ‣ Antarctic ice proves to be a good medium to study atmospheric neutrino oscillations → low-energy extension (PINGU, few GeV threshold) → study neutrino properties

25. The IceCube collaboration