Icecube Neutrino Observatory at the South Pole Kirill Filimonov, University of California, Berkeley, for the IceCube Collaboration
Cosmic rays: a 100 year-old mystery Victor Hess Nobel 1936 Balloon flights Equiv. LHC energy 1 event km -2 yr -1 Power law over many decades
Cosmic ray – -ray – Neutrino connection Neutrinos Cosmic accelerator (SNR, AGN, GRB, etc) Progenitor outflow Interstellar material Ambient photon field Cosmic ray e Photons p, He,... p + p p + e ± + e ( e )+ ( )
Neutrinos as Astronomical Messengers 10 9 Photons Neutrinos C.R B Neutrino Cosmic ray Energy (eV) CMB star-light Cosmic accelerator p, He,...
Neutrino interaction with matter W N e, e, W N e, , e, , Z N N tracks ( )Cascades ( e CC, e NC) Neutrino Telescope Hadronic Cascade > 3 km muon track 1 km Neutrino Telescope Cascade 0.7 o ( E / 10 TeV ) 0.7 ~
Why the South Pole? Antarctic Ice is the most transparent natural solid known Average optical ice parameters : abs ~ nm sca ~ nm
IceCube Collaboration Bartol Research Inst, Univ of Delaware, USA Pennsylvania State University, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA UC Berkeley, USA UC Irvine, USA Univ. of Alabama, USA Clark-Atlanta University, USA Univ. of Maryland, USA University of Kansas, USA Southern Univ. and A&M College, Baton Rouge, LA, USA University of Alaska, Anchorage Georgia Tech, USA Ohio State, USA Université Libre de Bruxelles, Belgium Vrije Universiteit Brussel, Belgium Université de Mons-Hainaut, Belgium Universiteit Gent, Belgium Universität Mainz, Germany DESY Zeuthen, Germany Universität Wuppertal, Germany Universität Dortmund, Germany Humboldt Universität, Germany MPI, Heidelberg Ruhr-Universität, Bochum Uppsala Universitet, Sweden Stockholm Universitet, Sweden Kalmar Universitet, Sweden Imperial College, London, UK University of Oxford, UK Utrecht University, Netherlands EPFL, Lausanne, Switserland Chiba University, Japan University of Canterbury, Christchurch, New Zealand 35 collaborating institutions
Where are we ? South Pole runway AMANDA-II Amundsen-Scott South Pole Station
+ N +X + N + X muon neutrino interaction track AMANDA: Proof of Concept Operation: 2000-March 31, strings, 677 Optical Modules Diameter of ~200m, height 500m
Atmospheric Muon Neutrinos Highest energy neutrinos ever detected (>100 TeV) Andres E, et al. Nature, 410 (2001) 441 arXiv:astro-ph/ Achterberg A. et al. PRD 76 (2007) Measured the atmospheric neutrino flux consistent with other measurements and predictions
Diffuse Neutrino Flux Search GZK E 2 d (GeV cm -2 s -1 sr -1 ) e dE E / GeV AMANDA-B10 Cascades (1 year) Galactic Atmospheric W.B. bound AMANDA-II μ (4 years) AMANDA-II Cascades (1 year) Baikal Cascades (5 years)
Diffuse Neutrino Flux Search GZK E 2 d (GeV cm -2 s -1 sr -1 ) e dE E / GeV AMANDA-B10 Cascades (1 year) Galactic Atmospheric W.B. bound AMANDA-II μ (4 years) AMANDA-II Cascades (1 year) Baikal Cascades (5 years) Waxman-Bahcall:Normalize neutrinos to extragalactic protons:
Diffuse Neutrino Flux Search GZK E 2 d (GeV cm -2 s -1 sr -1 ) e dE E / GeV AMANDA-B10 Cascades (1 year) Galactic Atmospheric W.B. bound AMANDA-II μ (4 years) AMANDA-II Cascades (1 year) Baikal Cascades (5 years) IceCube (1 year) Need bigger detector!
AMANDA 2450 m 1450 m 324 m IceTop: Surface Air Shower Array Digital Optical Module Next Step: IceCube Deep Core: (Low energy extension) IceCube: (“Main Instrument”) 80 Strings / 60 DOMs each 1 km 3 instrumented
Digital Optical Module Photomultiplier Tube
Digital Optical Module (DOM) … each DOM, independently collects light signals …time stamps them with 2 nanoseconds precision and sends them to an event builder … each DOM, independently collects light signals …time stamps them with 2 nanoseconds precision and sends them to an event builder Digitized Waveform
SCAR 2008K. Filimonov, UC Berkeley IceCube's 5 Megawatt Hot Water DrillHeaters Hose Drill Tower
SCAR 2008K. Filimonov, UC Berkeley
number of stringsyearrun length μ CR μ rate rate IC days80 Hz~ 1.7/day IC days550 Hz ~ 28/day IC402008~365 days1000 Hz~ 100/day IC80* years1650 Hz ~ 220/day
IceCube measures the atmospheric neutrino flux predicted: zenith angle number of PMT
Atmospheric muon neutrino spectrum IceCube 22 string analysis 4492 neutrino events at high purity (>95%)
Moon Shadow Cosmic rays blocked by the moon lead to a point-like deficit in the distribution of down-going muons in the detector.
Moon Shadow Cosmic rays blocked by the moon lead to a point-like deficit in the distribution of down-going muons in the detector. Need high statistics and good angular resolution!
Moon Shadow Pointing accuracy is confirmed!
175.5 days of livetime, events: 6796 up-going down-going high-energy muon events Preliminary Search for point sources: all-sky 40-strings (6month)
Hottest location in the all-sky search is: r.a.=114.95°, dec.=15.35° Pre-trial -log 10 (p-value) = 4.43 Best-fit # of source events = 7.1 Best-fit spectral index = 2.1 Preliminary No excess found! all-sky p-value is 61% not significant Search for point sources: all-sky
AMANDA-II 7 yr arXiv: string Discovery Potential: 5 σ in 50% of trials 40-string Sensitivity: Flux excluded at 90%cl ANTARES IC22 SK MACRO 80-string Sensitivity: Based on 40-string analysis Preliminary sens Point Sources E -2 Sensitivities, limits vs zenith angle
Diffuse Neutrino Fluxes WB bound AMANDA atm.
Large-scale anisotropy of downgoing muons IceCube (40 strings 2008) Anisotropies on the per-mille scale (skymap in equatorial coordinates) h TeV 126 TeV
Large-scale anisotropy of downgoing muons IceCube (40 strings 2008) Anisotropies on the per-mille scale (skymap in equatorial coordinates) h TeV 126 TeV Data: 22 strings, 4.3*10 9 events. Median angular Resolution: 3 o degrees. Median energy per cosmic ray particle: ~12 TeV.
IceCube &Tibet Array IceCube & Milagro M. Amenomori et. al Science, vol. 314, pp. 439–443, Oct A. Abdoet. al. ArXiv:astro-ph/ , IceCube skymap is consistent with Large scale anisotropy results reported by previous experiments looking at the northern hemisphere sky. Comparison with Tibet and Milagro
Summary IceCube construction is on schedule: – 59 of 86 strings in operation – Completion in February 2011 – AMANDA has been decommissioned IceCube meeting or exceeding its design parameters (angular resolution, effective area, dynamic range,…) Sensitivity growing rapidly cosmic ray (CR) spectrum, CR composition CR anisotropies atmospheric neutrinos (oscillations,effects of quantum gravity, … ) neutrino point sources gamma ray bursts multimessenger approaches diffuse fluxes dark matter magnetic monopoles supernova bursts shadow of the moon atmosphere physics glaciology new technologies for highest energies (radio, acoustics) IceCube high energy extension plans