1. 1 20th International Workshop on Weak Interactions and Neutrinos (WIN'05) http://amanda.uci.eduhttp://icecube.wisc.edu Neutrino Astronomy at the South Pole Latest results from AMANDA and perspectives for IceCube Paolo Desiati desiati@icecube.wisc.edu University of Wisconsin – Madison

2. 2 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 IAS, Princeton, USA University of Kansas, USA Southern Univ. and A&M College, Baton Rouge, LA, USA Institute for Advanced Study, Princeton, NJ, 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 Humbolt Universität, Germany Uppsala Universitet, Sweden Chiba University, Japan University of Canterbury, Christchurch, New Zealand Who is in IceCube ? Stockholm Universitet, Sweden Kalmar Universitet, Sweden Imperial College, London, UK University of Oxford, UK Utrecht University, Netherland Amundsen-Scott Station, Antarctica

3. 3 Amundsen-Scott South Pole Station South Pole Dome Summer camp AMANDA road to work 1500 m 2000 m [not to scale] Where are we ? IceCube

4. 4 PMT noise: ~1 kHz AMANDA-B10 (inner core of AMANDA-II) 10 strings 302 OMs Data years: 1997-99 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. 5 AMANDA IceCube IceTop IceCube 80 strings 60 OMs/string 17 m vertical spacing 125 m between strings IceTop 160 tanks frozen-water tanks 2 OMs / tank First year deployment (Jan 2005) 1 IceCube string (60 OMs) 8 IceTop Tanks (16 OMs) 10” Hamamatsu R-7081 1200 m

6. 6 Event detection in the ice O(km) long  tracks ~17 m cascades Longer absorption length → larger effective volume AMANDA-II  tracks pointing error : 1.5º - 2.5º σ [log 10 (E μ /TeV)] : 0.3 - 0.4 coverage : 2  Cascades (particle showers) pointing error : 30º - 40º σ [log 10 (E c /TeV)] : 0.1 - 0.2 coverage : 4  cosmic rays (+SPASE) combined pointing err : < 0.5º σ [log 10 (E p /TeV)] : 0.06 - 0.1 Nucl. Inst. Meth. A 524, 169 (2004) event reconstruction by Cherenkov light timing South Pole ice:ice the most transparent natural medium ? a neutrino telescope    0.65 o  (E /TeV) -0.48 (3TeV<E <100TeV)  ab s > ~ 110 m @ 400 nm  sca > ~ 20 m @ 400 nm

7. 7 ν astronomy : physics goals Protons which escape are bent => cosmic rays Photons which escape are absorbed above 50 TeV Neutrinos escapeNeutrinos AMANDA IceCube Bottom-Up scenario cosmic accelerator p + (p or  )    + X  e,  + X Energy  E ν -2 (fermi acceleration) Atm. ν  E ν -3.7 (energy separation) Array Still no evidence of TeV  detection from  o production Neutrino detection would demonstrate hadronic processes steady and transient point sources (point resolution) unresolved faint neutrino sources (diffuse ν ) expected extraterrestrial ν require km 3 scale detectors ! background rejection good acceptance high sensitivity

8. 8 ν astronomy : background Background rejection Cosmic ray μ main background Protons which escape are bent => cosmic rays Photons which escape are absorbed above 50 TeV Neutrinos escape Up/DownEnergy Source direction Arrival time Count rates Atmospheric ν × Diffuse ν, Cascades, UHE events ×× Point sources: AGN, WIMPs ××× GRB ×××× Supernovae × Preliminary data/mc ~ +30% normalized (statistical errors)

9. 9 ν astronomy : background Atmospheric  background & calibration beam First energy spectrum > 10 TeV Blobel regularized unfolding Protons which escape are bent => cosmic rays Photons which escape are absorbed above 50 TeV Neutrinos escape Preliminary importance of high energy prompt leptons background from charm still uncertain Expected high energy  flux

10. 10 telescope : AMANDA event energy deposited in OM time recorded on OM

11. 11 Detection of  from discrete steady bright or close sources (AGN, …) binned optimization in δ bands, versus a given signal hypothesis (  E -2 ) cosmic ray μ  background rejection good pointing resolution (good quality events) possible event-energy selection telescope : point source search signal bin background estimation background estimated from exp data with randomized α (i.e. time) signal obtained from full simulation obtain best sensitivity (average upper limit)

12. 12 detectorAMANDA-IIIceCube pointing resolution 1.5° ↑ -2.7° →~0.7° (> 10 TeV) (> 10 TeV bin search radius 3.6°  3.6° (min) 8.8°  8.8° (max) ~ 1° μ effective area ~0.025 km 2 (@ 10 TeV) ~ 0.8 km 2 (> 10 TeV) ~1.2 km 2 (> 100 TeV) AMANDA-II - 2000-02 (607 days)  declination  0 o   90 o  1 m 2  telescope : point source search Detection of  from discrete steady bright or close sources (AGN, …)

13. 13 telescope : point source search Average upper limit = sensitivity (δ>0°) (integrated above 10 GeV, E -2 signal) (*) optimized for E -2, -3 signal 1997 : ApJ 583, 1040 (2003) 2000 : PRL 92, 071102 (2004) 2000-02 : PRD 71 077102 (2005) IceCube IceCube : Astrop Phys 20, 507 (2004) average flux upper limit [cm -2 s -1 ] sin  AMANDA-B10 AMANDA-II Sensitivity independent of direction increases almost linearly with exposure *  lim  0.68·10 -8 cm -2 s -1  declination  0 o   90 o  average flux upper limit [cm -2 s -1 ] sin  AMANDA-B10 AMANDA-II IceCube 1/2 year * Preliminary

14. 14 telescope : point source search PRD 71 077102 (2005) AMANDA-II - 2000-02 (607 days)

15. 15 telescope : point source search  also search for neutrinos from unresolved sourcesalso search for neutrinos from unresolved sources Preliminary Search for clustering in northern hemisphere compare significance of local fluctuation to atmospheric  expectations un-binned statistical analysis no significant excess 2000-2003 (807 days) 3329 from northern hemisphere 3438  expected from atmosphere ~92% Maximum significance 3.4  compatible with atmospheric

16. 16 telescope : unresolved sources ? neutrinos from single steady sources may be as many as background enhance detection using: on the way stacking steady point source candidates ( on the way ) catalogue of possible neutrino emitter AGN candidates and selection optimization on the ensamble to enhance sensitivity preliminary results preliminary results time correlation with transient phenomena ( preliminary results ) preliminary results known active flary periods of TeV gamma sources time-rolling search of signal excess over background preliminary results diffused flux of neutrinos with no time-space correlations ( preliminary results ) calculate upper limit on high energy tail of atmospheric ν μ optimize selection with attention to background(s) rejection multi-flavor (muon tracks + cascades)

17. 17 telescope : point source search Detection of  from known active flary periods periods (during 2000-03) and sources selected on the basis of the available multi- wavelength information the wavelengths investigated are possible indicators for a correlated neutrino emission (X-ray for Blazars and radio for Microquasars) based on hypothesis neutrinos are emitted in coincidence with electromagnetic flare emissions SourceEM light curve source Livetime in periods of high activity Nr. of n events in high state Expected backgr. in high state Markarian 421ASM/RXTE141 days01.63 1ES1959+650ASM/RXTE283 days21.59 Cygnus X-3Ryle Telesc.114 days21.37

18. 18 telescope : point source search Detection of  with time rolling search events time sliding window time window: 40 / 20 days for Extragalactic / Galactic Objects angular bin: 2.25°-3.75° SourceNr. of n events (4 years) Expected backgr. (4 years) Period duration Nr. of doublets Chance probability Markarian 42165.5840 days01 1ES1959+65053.7140 days10.34 3EG J1227+4302 64.3740 days10.43 QSO 0235+16465.0440 days10.52 Cygnus X-365.0420 days01 GRS 1915+10564.7620 days10.32 GRO J0422+3255.1220 days01

19. 19 telescope : diffused sources no space-time correlation which helps in rejecting background signal hypothesis with harder energy spectrum than background (Fermi acceleration)  10 -6 × E -2  E -3.7 requires good understanding of background(s) requires detector systematics to be under control relies on simulation of background and signal events sensitivity to high energy tails (up to ~ PeV) # hit Optical Modules

20. 20 telescope : diffused sources energy reconstruction with NN acceptance correction with regularized Blobel unfolding confidence interval construction according to FC prescription set upper limit on last bin Φ ν E 2 < 2.6 × 10 -7 GeV cm -2 s -1 sr -1 (100 TeV < E < 300 TeV) extending to longer exposure (2000-03) Preliminary year 2000 optimization on observables for background rejection and event quality energy estimator is the number of hit OM best expected sensitivity (2000-03) : Φ ν E 2 < 9 × 10 -9 GeV cm -2 s -1 sr -1 (10 TeV < E < 5 PeV) ν μ : 2 π coverage

21. 21 telescope : diffused sources Cascades: 4 π coverage N obs = 1 event N atm μ = 0.90 N atm ν = 0.06 ± 25% norm +0.69 -0.43 +0.09 ­0.04 After optimized cuts: Astroparticle Physics 22 (2004) 127 background ν e signal no earth propagation effects   e year 2000 E ~160 TeV

22. 22 Neutrino flavor identification Neutrino flavor Log(ENERGY/eV) 1218 156 219 e e   supernovae Full flavor ID Showers vs tracks AMANDA flavor ID IceCube flavor ID, direction, energy IceCube triggered, partial reconstruction Tau Neutrinos: Regeneration: earth quasi- transparent to  Enhanced  & cascade flux due to secondary , e

23. 23 telescope : diffused sources UHE: 4 π coverage Astroparticle Physics 22 (2005) 339 Earth opaque to PeV neutrinos → look up and close to horizon Look for very bright events (large number of Optical Modules with hits) Train neural network to distinguish E -2 signal from background N obs = 5 events N bgr = 4.6 ± 36% events Simulated UHE event Φ ν E 2 < 0.99·10 –6 GeV cm -2 s -1 sr -1 (1 PeV < E < 3 EeV) year 1997 (AMANDA-B10)

24. 24 all-flavor limits diffuse (B10 1yr) diffuse (A-II 4yr) diffuse (A-II 1yr) cascade (A-II 1yr) UHE (B10 1yr) cascade (B10 1yr) telescope : diffused summary limits on all-flavor limits on E -2 would need to model other spectra x3

25. 25 telescope : diffused summary diffused analysis in B10 (year 1997) PRL 90 (2003), 251101

26. 26 telescope : Galactic Plane interaction of CR in interstellar medium expected to produce a flux of neutrinos from the galactic disk same energy spectrum as CR  E -2.7 modelled π o component of γ rays in 4GeV < E < 10GeV has σ~2.1 o in galactic latitude (Strong et al., ApJ 613, 2004) AMANDA-II angular resolution ~ 1.5 o – 2.5 o ~constant column density in visible galactic longitude gaussian-distributed line source of neutrinos from the galactic disk, isotropic in galactic longitude → gaussian-distributed line source of neutrinos from the galactic disk, isotropic in galactic longitude sensitivity optimized by an appropriate choice of the on- source region width (i.e. galactic latitude width) optimal region width is  4.4 o (contains >90% of signal) 90% of selected events in energy range 130GeV < E < 30 TeV preliminary sensitivity significantly above predictions

27. 27 telescope : Gamma Ray Bursts use space-time localization of the events. Two approaches underway: Waxman-Bahcall average spectrum hypothesis ν μ search using 312 BATSE bursts (1997-2000) & 139 BATSE+IPN bursts (2000-2003) preliminary preliminary upper limits (of ν μ ) at Earth: 1997-2000Φ ν E 2 < 4 × 10 -8 GeV cm -2 s -1 sr -1 2000-2003Φ ν E 2 < 3 × 10 -8 GeV cm -2 s -1 sr -1 ongoing ongoing all-flavor search using 74 BATSE bursts (2000) ongoing ongoing cascade-like time rolling search with no external trigger (2001) burst-specific prompt spectrum hypothesis ongoing ongoing ν μ search using 200 BATSE bursts (1997-2000) GRB030329

28. 28 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

29. 29 Indirect WIMP detection Disfavored by direct search (CDMS II) Limits on muon flux from Earth centerLimits on muon flux from Sun PRELIMINARY

30. 30 from Supernovæ SNEWS is a collaborative effort between Super-K, SNO, LVD, KamLAND, AMANDA, BooNE and several gravitational wave experiments Bursts of low-energy (MeV) neutrinos from core collapse supernovae AMANDA detection: - simultaneous increase of all PMT count rates (~10 s) - can detect 90% of SN within 9.4 kpc - less than 15 fakes per year detection radius AMANDA-II AMANDA-B10 IceCube 30 kpc AMANDA-B10 sees 70% of the galaxy AMANDA-II sees 90% of the galaxy IceCube will see out to the LMC

31. 31 IceCube: the future first IceCube string deployed (60 Digital OM) first 4 IceTop Stations deployed (8 tanks/16 Digital OM) DOM being deployed in the ice DOM in the tank ice

32. 32 IceCube : DOM Mainboard back 2xATWD FPGA Memories HV Board Interface CPLD FPGA (Excalibur/Altera) reads out the ATWD handles communications time stamps waveforms system time stamp resolution 7 ns wrt master clock FPGA (Excalibur/Altera) reads out the ATWD handles communications time stamps waveforms system time stamp resolution 7 ns wrt master clock oscillator (Corning Frequency Ctl) running at 20 MHz maintains df/f < 2x10 -10 2 four-channel ATWDs Analog Transient Waveform Digitizers low-power ASICs recording at 300 MHz over first 0.5ms signal complexity at the start of event 2 four-channel ATWDs Analog Transient Waveform Digitizers low-power ASICs recording at 300 MHz over first 0.5ms signal complexity at the start of event Dynamic range  200 p.e./15 ns  2000 p.e./5 ms energy measurement (TeV – PeV) Dead time < 1% fast ADC recording at 40 MHz over 5 ms event duration in ice

33. 33 An IceCube-IceTop event

34. 34 An AMANDA-IceCube event verification of newly deployed string off-line synchronization of AMANDA and IceCube data

35. 35 IceCube deployment plan January 05: Strings: 1 Tanks/stations: 8/4 05/06 Plan*: Strings: 10 - 12 Tanks/stations: 24/12 runway

36. 36 Neutrino flavor identification Neutrino flavor Log(ENERGY/eV) 1218 156 219 e e   supernovae Full flavor ID Showers vs tracks AMANDA flavor ID IceCube flavor ID, direction, energy IceCube triggered, partial reconstruction Tau Neutrinos: Regeneration: earth quasi- transparent to  Enhanced  & cascade flux due to secondary , e

37. 37 IceCube flavor neutrino detection E µ = 10 TeV e  e E = 375 TeV ~300m for 10 PeV t μ  μ τ  τ + “cascade”

38. 38 IceCube high energy extension in AMANDA in IceCube Simulated 2×10 19 eV neutrino event

39. 39 IceTop : high energy EAS detection Small showers (2-10 TeV) associated with the dominant  background in the deep detector are detected as 2-tank coincidences at a station. Detection efficiency ~ 5% provides large sample to study this background Showers triggering 4 stations give ~300 TeV threshold for EAS array Large showers with E ~ 100-1000 PeV will clarify transition from galactic to extra-galactic cosmic rays.

40. 40 IceTop : EeV detection  Penetrating muon bundle in shower core Incident cosmic- ray nucleus Threshold ~ 10 18 eV to veto this background Potential to reject this background for EeV neutrinos by detecting the fringe of coincident horizontal air shower in an array of water Cherenkov detectors (cf. Ave et al., PRL 85 (2000) 2244, analysis of Haverah Park)

41. 41 Summary No Extraterrestrial neutrino signal observed yet ! AMANDA-II upper limits getting tighter and constraining models higher event statistics good ice properties understanding improving background rejection capabilities still improving reconstruction event quality backgroundtoward clean atmospheric ν μ measurement as background improve strategies for sensitivity enhancement IceCube/IceTop in verification phase (engineering data and preliminary tests) IceCube/IceTop will significantly improve astrophysics and cosmic rays measurements in energy range and resolution IceCube will be a powerful all-flavor neutrino detector (particle physics)particle physics IceTop will open the CR measurements up to ~ EeV with high resolution use of PMT waveforms is a new tool we are learning to use AMANDA will overlap the lower energy tail of IceCube sensitivity

42. 42 “The “ @ South Pole thank you

43. 43 Polar ice optical properties Measurements: ►in-situ light sources ►atmospheric muons Average optical ice parameters: abs ~ 110 m @ 400 nm sca ~ 20 m @ 400 nm att ~ 17 m @ 400 nm Scattering bubbles dust Absorption dust ice back

44. 44 Mediterranean sea optical properties Average optical ice parameters: abs ~ 63.3 m @ 440 nm sca ~ 80.8 m @ 440 nm att ~ 35.5 m @ 440 nm back abs att Average values 2850÷3250 m

45. 45 AMANDA :  Aeff AMANDA-B10 AMANDA-II back

46. 46 IceTop back Rates of contained coincident events 125 m grid, km 2 air shower array at 690 g/cm 2 E threshold ~ 300 TeV for > 4 stations in coincidence Useful rate up to ~ EeV Total rate 1-2 kHz Median E primary = 3.5 TeV Small showers trigger station if within ~30 m Direct tag for few % of muon background (~50 Hz out of 1-2 kHz)

47. 47 IceCube :  Aeff & resolution Galactic center back

48. 48 NEMO :  Aeff & resolution back Up-going muons with E -1 spectrum 60 kHz background Reconstruction + Quality Cuts Nemo20m 140 (5832 OM) Lattice 125 16 (5600 OM) From Neutrino 2004 talk by P. Piattelli http://nemoweb.lns.infn.it

49. 49 IceCube : simulated  track events back E µ =6 PeV, 1000 hitsE µ =10 TeV, 90 hits

50. 50 IceCube : sensitivities Diffuse   sensitivityPoint source   sensitivity back