Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Connections IceCube – KM3NeT Christian Spiering DESY Content • Lessons from IceCube • • • • „Multi-wavelength“ point source searches Network of Target of Opportunity projects Other coordinated efforts Cooperation on software and algorithms • Formal questions Lessons from IceCube (and from theoreticians) • How big a detector ? • Optimization to which energy range ? • Which configuration ? How big a detector ? • KM3NeT: „Substantially more sensitive than IceCube“ • Point sources: factor ~2 from angular resolution alone • This is by far not enough in case IceCube would not have identified sources in 2010/11 • Need something like the „canonical factor 7“ – LHC LHC upgrade (in luminosity) – 50 kt Super-K 300 kt DUSEL/Hyperkam (in volume) – Auger-South Auger North (in area) • Need much more than a cubic kilometer in volume !! Early IceCube spacing exercises • Increasing the string spacing from 100 to 180 m increases: IceCube: 125 m – volume by factor 3 – 5 sensitivity by 40% • We have been reluctant to go to the largest spacing since: – String-to-string calibration may work worse. – Due to light scattering in ice the sensitivity increases much weaker than the area for large spacing. – We were optimistic w.r.t. the signal expectation. E-2 Early IceCube spacing exercises • Increasing the string spacing from 100 to 180 m improves: IceCube: 125 m – volume by factor 3 – 5 sensitivity by 40% • We have been reluctant to go to the largest spacing since: – String-to-string calibration may work worse. – Due to light scattering in ice the sensitivity increases weaker than the area for very large spacing. – We were optimistic w.r.t. the signal expectation. Would be no concern today Not important in water Too optimistic Threshold for best sensitivity 1 cubic kilometer IceCube Diffuse E-2 flux Blue: after downgoing muon rejection Red: after cut for ultimate sensitivity Threshold for best sensitivity 1 cubic kilometer IceCube Point sources (E-2) Blue: after downgoing muon rejection Red: after cut for ultimate sensitivity Threshold for best sensitivity Several cubic kilometers Point sources (educated guess) Threshold between 3 and 5 TeV ! Blue: after downgoing muon rejection Red: after cut for ultimate sensitivity Ceterum censeo: • Optimize to energies > 5 TeV, even if you have to sacrifice lower energies! 208m 624m • See original GVD/Baikal with muon threshold ~ 10 TeV (but, alas, < 1 km³) 70m 280 m 12 0m 70 m Expected n flux from galactic point sources, example: RXJ 1713-3946 (see also Paolo Lipari’s talk) Assume p0 g and calculate related p± n C. Stegmann ICRC 2007 Milagro sources in Cygnus region Halzen, Kappes, O’Murchadha Probability for fake detection: • 6 stacked sources • Assumption: cut-off at 300 TeV • p-value <10-3 after 5 years • Optimal threshold @ 30 TeV (determined by loss of signal events) Aharonian, Gabici etc al. 2007 atmospheric neutrinos (green) vs. source spectra with - different spectral index (no cut-off) - index = 2 and cut-off at 1 and 5 PeV. normalized to dN/dE (1 TeV) = 10-11 TeV-1 cm-2 s-1 Aharonian, Gabici etc al. 2007 atmospheric neutrinos (green) vs. source spectra with - different spectral index (no cut-off) - index = 2 and cut-off at 1 and 5 PeV. normalized to dN/dE (1 TeV) = 10-11 TeV-1 cm-2 s-1 What about the low energies when increasing the spacing? • Instrumenting a full cubic kilometer with small spacing is not efficient since for low fluxes a further increase of the low energy area will yield low-energy signal rates which are much lower than the atmospheric neutrino background rates. • Better: a small nested array with small spacing – enough „exhaust“ the potential at low energy. to • Don‘t distribute the small spacing areas over the full array but concentrate it in the center – – – – Better shielding No empty regions Better performance for contained events … • DeepCore! IceCube with DeepCore IceCube with DeepCore VETO low-energy nested array Early IceCube Exercises 12 clusters of strings NT1000: top view L~ 350 m The present Baikal scenario Compare to KM3NeT scenarios: a c b d Content • Lessons from IceCube • • • • „Multi-wavelength“ point source searches Network of Target of Opportunity projects Other coordinated efforts Cooperation on software and algorithms • Formal questions If n telescopes would be only sensitive up to horizon …. IceCube „blind“ Antares Baikal KM3NeT „blind“ … resulting in: point source limits/sensitivities Overlap region 25% at any given moment, 70% of IceCube sky seen by KM3NeT at some moment. Actually you can look above horizon for higher energies: +15° +75° +60° +45° 24h 0h +30° +15° 24h 0h -15° -30° -45° R. Lauer, Heidelberg Workshop, Jan09 arXiv:0903.5434 IceCube 22 strings, 2007 Actually you can look above horizon for higher energies: +15° +75° +60° +45° 24h 0h +30° +15° 24h 0h -15° -30° -45° IceCube 22 strings, 2007 Actually you can look above horizon for higher energies: IceCube 40 strings 6 months 2008 Differential IceCube sensitivity to point sources (IC-40, 1 year, 5 discovery potential, normalized to ½ decade) Taken from Chad Finley, MANTS = +30° = +60° = +6° TeV PeV Differential IceCube sensitivity to point sources (IC-40, 1 year, 5 discovery potential, normalized to ½ decade) Taken from Chad Finley, MANTS = +30° = -8° = -30° = -60° = +60° = +6° TeV PeV Spectral form for extra-galactic sources Multi-wavelength analysis of individual sources ? = +30° = -8° = -30° = -60° = +60° = +6° Blazars Stecker 2005 GRB-precursor Razzaque 2008 3 TeV 4 WB prompt GRB 5 6 PeV 7 BLacs Mücke et al 2003 8 9 Compare to absolute predictions Taken from Chad Finley, MANTS = +30° = -8° = -30° = -60° = +60° Crab =+22° MGRO J1908 =+6° = +6° 3C279 =-6° • Predicted neutrino fluxes for a few selected sources (full lines) • IC40 approximate 90% CL sensitivity to sources according to flux model and declination (dashed lines) Multi-wavelength/full sky analysis • Cover 4p with 2 detectors full sky map • Add evidences/limits in overlap regions • Combine TeV-PeV information from lower hemisphere of one detector with PeV-EeV information from upper hemisphere of the other detector multiwavelength analysis over 3-5 orders of magnitude in wavelength / energy. • Need: – – – – Coordinated unblinding procedures Coordinated candidate source list (also for source stacking) Point spread functions Effective areas as function of energy Alert Programs • GRB information from satellites – offline analysis, online: storage of unfiltered data & high efficiency at low E (like Antares) • Optical follow-up: n telescopes robotic optical telescopes • Gamma follow-up (NToO): n telescopes Gamma telescopes • Supernova burst alert: IceCube (also KM3NeT? ) • Arguably, the ratio of signal to background alerts from n telescopes is an issue. Alert programs have to be coordinated worldwide, be it only not to swamp optical/gamma telescopes with an unreasonable number of alerts. Optical Follow-Up Antares Optical follow-up „Neutrino Target of Opportunity“ Alert Programs • GRB information from satellites – offline analysis, online: storage of unfiltered data & high efficiency at low E (like Antares) • Optical follow-up: n telescopes robotic optical telescopes • Gamma follow-up (NToO): n telescopes Gamma telescopes • Supernova alert (IceCube) • IceCube triggers KM3NeT and vice versa ? Test: Antares IceCube Presentation of WIMP results Classes of tested models Presentation of model parameter space Comparison with direct searches Other examples GRB stacking Combine KM3NeT/IceCube GRB lists, increasing the overall sensitivity Diffuse fluxes Any - high energy excess (extraterrestrial or prompt n) - high energy deficit (QG oscillations) should be confirmed by an independent detector, with different systematics Confirmation of exotic events Slowly moving particles (GUT monopoles, Q-balls, nuclearites) artefacts or reality? Software and algorithms MoU between IceCube and KM3NeT summer 2008 Framework: IceTray KM3Tray SeaTray (now official software framework for ANTARES and KM3NeT) Improvements, debugging KM3NeT IceCube Modules (future): KM3NeT IceCube Simulation (event generators, air showers,…) Reconstruction methods Use of waveforms Basic algorithms (like - already now – Gulliver fitting) Content • Lessons from IceCube • • • • „Multi-wavelength“ point source searches Network of Target of Opportunity projects Other coordinated efforts Cooperation on software and algorithms • Formal questions Formal framework Memoranda of Understanding on specific items like that on IceTray Yearly common meetings Similar to the one we had in Berlin (MANTS) Inter-collaboration working groups which „synchronize“ statistical methods, ways of presentation, simulations, … (for point sources, diffuse fluxes, dark matter, …) Global Network ? Like LIGO/Virgo/GEO Global Neutrino Observatory, with inter-collaboration committees ? like Auger, CTA Formal framework Memoranda of Understanding on specific items like that on IceTray Yearly common meetings Similar to the one we had in Berlin (MANTS) Inter-collaboration working groups which „synchronize“ statistical methods, ways of presentation, simulations, … for point sources, diffuse fluxes, dark matter Global Network ? Like LIGO/Virgo/GEO Could start this with the full community Global Neutrino Observatory, with inter-collaboration Antares/KM3NeT, Baikal) committees(IceCube, ? like Auger, CTA A global network ? But first of all …. … let IceCube* try to do the best it can do for KM3NeT: …see a first source ! * and ANTARES. Who knows ? Acknowledement Part of this talk is based on talks given at the MANTS Meeting, September 2009, in Berlin. Special thanks to: Teresa Montaruli Jürgen Brunner Chad Finley Tom Gaisser, Uli Katz, Francis Halzen