High Energy Astrophysics and Multi-messenger and IceCube

1. High Energy Astrophysics and Multi-messenger and IceCube • teresa.montaruli@unige.ch Journée de réflexion du DPNC, Jun. 18, 2012

2. 4 Astrophysics from ground: middle size infrastructures Middle-ground = 200M$ scale projects 1 km^2 IceCube 250 scientists CTA 1000 scientists } worldwide CTA Vittorio’s talk

3. What is the physics addressed by IceCube? Paper in Nature 484, April 2012 (non observation of GRB events imples GRBs are not main sources of UHECRs or fireball needs to be revisited), 15 published in 2012 15 published papers in 2011, 13 published in 2010, 10 in 2009 About 73 in total (including AMANDA)

4. IceCube IceCube 59 (2009-10) IceCube 59 (2009-10) data analysis almost complete IceCube 79 (2010-11) Point source unblinding by Juanan in a few days IceCube 86 (2010-11) EHE data analyzed and presented at Neutrino 2012 Completed in January 2011 on schedule and with 6 more strings

5. Upgoing and Downgoing neutrinosand backgrounds Text

6. Detection principle μ ν

7. To be able to see UHE events and reasonable statistics for low-luminosity beams Why so large? 2 events / 672.7 days - background (atm. m + conventional atm. n) expectation 0.14 events preliminary p-value: 0.0094 (2.36σ)

8. How to reduce the large atmospheric neutrino and muon backgrounds? 2) Diffuse flux searches extect more events because they are integrated over the sky and can use energy but are subject to larger systematic errors

9. ≈E-2.7 galactic ≈E-3 ≈E-3.2 ≈E-2.7 extra-galactic Power-law spectra At source: 1st Fermi acceleration in non-relativistic shocks / simulations of relativistic shocks in AGN jets: Propagation effects in the Galaxy steepens to E-2.7 Further changes connected to change of sources. Cosmic ray power is connected to source power. Cosmic ray composition is connected to source one. They are key to understand: - acceleration of particles at the outmost power - highest energy phenomena where standard physics may break

10. Why also gammas and neutrinos? • Nature paper in Apr. 2012 demonstrated absence of neutrinos from gammas and limits severely constrain the GRB fireball model normalized to UHECRs or the GRBs are UHECR sources • The total source power is distributed between neutrinos and radio-to-γ-rays emission. We can normalize neutrino predictions to gamma total observed power. • Other UHECR possible sources: protons must be accelerated together with electrons in BH jets. Eg: matter falls onto BH or n-star driving relativistic jets perpendicular to the disc plane. • Protons will loose energy in pp and pγ interactions or synchrotron emission. • In principle the SED can fully be explained by IC in the high energy region of the photons up scattered by the synchrotron emitted photons at lower energies but there is is room for an hadronic component from π0 decay due to pp or p-gamma interactions. Cyg A MWL measurements IC synchrotron

11. Multi-messenger astronomy • For π0 dominated: neutrinos and gamma-rays spectrum are correlated. • For cascade dominated: total electromagnetic power is needed to estimate the total neutrino flux. Ethr = 1.2 GeV always cascade dominated, additional parameter T of photon field excluded C. Tchernin, J.A. Aguilar, A. Neronov, T.M almost submitted

12. Multimessenger and the unexpected in neutrino astronomy `Cocoon’: only neutrinos neutrons escape => CRs & νs and gammas confined protons attain sufficient Emax to produce UHECRs neutrons escape before decaying sufficient interactions to produce neutrons & νs Neutrinos prove matter acceleration in sources, keep their direction, probe their cores

13. observed value 74.2% Point source 40+59 string results Atm. neutrinos Atm. muons Hottest spot: ra: 75.45 dec: - 18.15 -log10(p-value) = 4.65 nSrcbest = 18.3 γbest= 3.9

14. Point sources: E-2 median sensitivity and upper limits (90%cl) Juanan’s new result to be unblinded in a whilea while Results for IceCube 40, Astrophys.J.732:18,2011 ANTARES, arXiv:1108.0292

15. Multi-messenger analysis adding time to reduce atmospheric backgrounds: flares • triggered search uses lightcurves from Fermi and gamma-ray telescopes • untriggered gave 1% p-value 59 strings Hottest spot: ra: 21.25 dec: -0.25 -log10(p-value) = 6.69 nSrcbest = 14.5 σbest= 5.5 days AGN flares and sky scan: Astrophys.J. 744 (2012) 1 Crab flare: Astrophys.J. 745 (2012) 45 Microquasar periodic search: Astrophys.J. 748 (2012) 118

16. Direction and energy but larger systematics CR composition knowledge at and above the knee matters Diffuse fluxes with νμ upgoing Limit is well below the upper bound on diffuse flux of neutrinos obtained normilizing the power of sources to observed UHECR spectrum

17. Cosmological neutrinos: horiz. and downgoing 79+86 strings 672.7 d Models can be normalized on UHECR seen in Auger/HiReS and GeV diffuse flux in Fermi

18. Where do limits stand?

19. No directionality but energy Found 14 “cascade” events (11.6 bckg) after cuts in a total livetime of 373.6 days up to 175 TeV Diffuse fluxes with cascades NC, ντ νe

20. Tom Gaisser’s interpratation Why aren’t we yet seeing a clear evidence of astrophysical neutrinos?

21. The low energy frontier

22. Initial Neutrino oscillation results

23. - Data indicate that astrophysical neutrinos may be already popping up in our data in diffuse searches - Point sources need more time because of lower fluxes but limits are stringent indicating that probably the target mass where interactions occur is lower than expected - Diffuse fluxes need large excess because of systematics In the future low energy searches and UHE searches can be powered with new arrays (PINGU and ARA) - IceCube low energy extensions (DeepCore and PINGU) improve the already great potentials of IceCube for SN explosion monitoring and lightcurve detection adding potentials on energy reconstruction; for DM; for fundamental neutrino physics. PINGU/DeepCore have potential for sterile neutrino (given the many baselines/E) and for MH. DeepCore already convincingly demonstrates oscillations, with PINGU (30M$) will go into MH.  Conclusions and future perspectives Infill of the IceCube DeepCore with 20 strings (PINGU) to lower Eth to a few GeV

24. Surprisingly large θ13 → possible measurement of Mass Hierarchy by means of the atmospheric neutrino beam MH discrimination: 10% variation of the relative atm muon neutrino rates (1 yr) for NI and NH in cosθz accounting for energy and angular resolutions ➞Large significance can be achieved in 5 yr Synergy with long baseline experiments that can confirm the result and also have the very important task of precision of parameter measurements and fundamental CP parameter(s) measurements.

25. (Pγ) exclusion plots