1 Particles and Nuclei International Conference (PANIC05) Santa Fe, NM (U.S.A.) October 24 th, from Quark n.36, 02/01/04 Neutrino Astronomy at the South Pole Latest results from the AMANDA-II Neutrino Telescope Paolo Desiati on behalf of the IceCube Collaboration University of Wisconsin – Madison

2 Who is in IceCube ? University of Canterbury, Christchurch, New Zealand Chiba University, Japan 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 Institute for Advanced Study, Princeton, NJ, USA 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 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 Uppsala Universitet, Sweden Stockholm Universitet, Sweden Kalmar Universitet, Sweden Imperial College, London, UK University of Oxford, UK Utrecht University, Netherland Amundsen-Scott Station, Antarctica

3 Where are we ? South Pole Runway AMANDA-II Amundsen-Scott South Pole Station

4 PMT noise: ~1 kHz AMANDA-B10 (inner core of AMANDA-II) 10 strings 302 OMs Data years: Optical Module “Up-going” (from Northern sky) “Down-going” (from Southern sky) AMANDA-II 19 strings 677 OMs Trigger rate: 80 Hz Data years: >=2000 PMT looking downward

5 Event detection in the ice O(km) long  tracks ~17 m O(10m) cascades event reconstruction by Cherenkov light timing a neutrino telescope    0.65 o  (E /TeV) (3TeV<E <100TeV) Events pointing resolution Energy resolution σ[log 10 (E μ /TeV)] coverage  tracks 1.5º - 2.5º0.3 – 0.4 22 cascades30º - 40º0.1 – 0.2 44 cosmic rays + SPASE combined < 0.5º0.06 – 0.1- Nucl. Inst. Meth. A 524, 169 (2004)

6 Polar ice optical properties Average optical ice parameters: abs ~ nm sca ~ nm prop ~ nm Scattering bubbles dust Absorption dust ice Measurements: ►in-situ light sources ►atmospheric muons

7 ν astronomy : physics goals AMANDA IceCube Bottom-Up scenario cosmic accelerator p + (p or  )    + X  e,  + X Flux  E ν -2 (fermi acceleration) Array

8 ν astronomy : backgrounds Preliminary (statistical errors) intense muon flux from CR  - background for CR neutrinos ν μ fluxes from CR  - background for ET neutrinos conventional, prompt ET neutrinos as excess of measured neutrino flux at high energies (  E -2 )

9 Up/DownEnergy Source direction Arrival time Count rates Atmospheric ν × Diffuse ν, Cascades, UHE events ×× Point sources: AGN, WIMPs ××× GRB ×××× Supernovae × background rejection

10 AMANDA-II (607 days)   telescope : point source search average flux upper limit [cm -2 s -1 ] sin  AMANDA-B10 AMANDA-II signal bin background estimation 1997 : ApJ 583, 1040 (2003) 2000 : PRL 92, (2004) : PRD (2005) IceCube IceCube : Astrop Phys 20, 507 (2004) Average upper limit = sensitivity (δ>0°) (integrated above 10 GeV, E -2 signal) Neutrino Effective Area 1 m 2  signal hypothesis  E -2

11 telescope : point source search Preliminary Search for clustering in northern hemisphere compare significance of local fluctuation to atmospheric  expectations un-binned statistical analysis no significant excess (807 days) 3329 from northern hemisphere 3438  expected from atmosphere ~92% Maximum significance 3.4  compatible with atmospheric

12 telescope : unresolved sources ? neutrinos from single steady sources may be as many as background SourceEM light curve source high activity #events in high state Expected backgr. in high state Markarian 421ASM/RXTE141 days ES ASM/RXTE283 days21.59 Cygnus X-3Ryle Telesc.114 days21.37 time-correlation with transient phenomena ( ) known active flary periods of TeV gamma sources if neutrinos in coincidence with gamma emission Source#events (4 years) Expected backgr. (4 years) Period duration #doubletsChance probability Markarian d01 1ES d EG J d10.43 QSO d10.52 Cygnus X d01 GRS d10.32 GRO J d01 time-rolling search over period optimized angular search bin : 2.25°-3.75° search neutrinos in time-space coincidence with GRB ν μ and all-flavor searches with Waxman-Bahcall spectrum all-flavor rolling-time search with WB spectrum 1 and 100 s time windows GRB case with specific spectrum based on observed electromagnetic parameters (Band fit, red shift): astro-ph/ SGR (Dec 27 th 2004): astro-ph/ muons from gamma interaction in atmosphere no signal detected therefore limits assigned stacking source analysis (2000) single point source sensitivity (4yrs) limit / source

13 telescope : stacking point source Preliminary

14 telescope : diffused sources atm ν μ unfolded spectrum : limit (2000, 197d) Φ ν E 2 < 2.6 × GeV cm -2 s -1 sr -1 (100 TeV < E < 300 TeV) Preliminary HE ν μ - tracks : 2 π coverage energy estimator = # hit OM : sensitivity ( , 807d) PRELIMINARY Φ ν E 2 < 9.5 × GeV cm -2 s -1 sr -1 (no syst) PRELIMINARY (13 TeV < E < 3.2 PeV) HE ν e +ν μ +ν τ - cascades : 4 π coverage HE cascades : limit (2000, 174d) Φ ν E 2 < 8.6 × GeV cm -2 s -1 sr -1 (50 TeV < E < 5 PeV) Astroparticle Physics 22 (2004) 127

15 telescope : diffused sources UHE ν e +ν μ +ν τ :4 π coverage Earth opaque to PeV neutrinos → look up and close to horizon Look for very bright events (large number of multiple hits / sensor) Train neural network to distinguish E -2 signal from background simulated UHE event in AMANDA-B10 Astroparticle Physics 22 (2005) 339 UHE cascades : limit (1997, 131d) Φ ν E 2 < 9.9 × GeV cm -2 s -1 sr -1 (1 PeV < E < 3 EeV) UHE cascades : limit (2000, 174d) Φ ν E 2 < 3.5 × GeV cm -2 s -1 sr -1 (0.2 PeV < E < 2 EeV)

16 all-flavor limits ν μ (B10 1yr) ν μ (A-II 4yr) ν μ (A-II 1yr) ν e +ν μ +ν τ (cascades A-II 1yr) ν e +ν μ +ν τ (UHE B10 1yr) ν e (cascades B10 1yr) telescope : all-flavor summary limits on E -2 would need to model other spectra oscillations Earth all-flavor limits / 3 ν e +ν μ +ν τ (UHE A-II 1yr) sensitivity limit

17 Indirect WIMP detection Sun  Earth Detector Freese, ’86; Krauss, Srednicki & Wilczek, ’86 Gaisser, Steigman & Tilav, ’86 Silk, Olive and Srednicki, ’85 Gaisser, Steigman & Tilav, ’86    velocity distribution  scatt  capture  annihilation interactions int.  int. interactions hadronization

18 Indirect WIMP detection Disfavored by direct search (CDMS II) Limits on muon flux from SunLimits on muon flux from Earth center

19 “The South Pole No Extraterrestrial neutrino signal observed yet ! AMANDA-II upper limits getting tighter and constraining models ice properties well understood improving background rejection capabilities still improving reconstruction event quality backgroundtoward clean atmospheric ν μ measurement as background improve strategies for sensitivity enhancement AMANDA will overlap the lower energy tail of IceCube sensitivity