IceCube : Status and Results

IceCube: Status and IceCube: Status and ResultsResults IntroductionIntroduction Detector Description and StatusDetector Description and Status Physics with IceCube, Some Recent Physics with IceCube, Some Recent

ResultsResults ConclusionsConclusions AcknowledgementAcknowledgement

Ali R. Fazely, Southern Universityfor the IceCube Collaboration

icecube.wisc.eduMiami Conference, 12/14-19/2010

Latest News!Latest News!Completion of the IceCube Completion of the IceCube

DetectorDetector

The IceCube Detector will be fully The IceCube Detector will be fully installed by Sunday 12/19/2010 installed by Sunday 12/19/2010 and the press release from NSF and the press release from NSF will follow on Monday.will follow on Monday.

Miami Conference, 12/14-19/2010

What is IceCube?What is IceCube?

A gigaton neutrino detector funded A gigaton neutrino detector funded through the National Science through the National Science Foundation and EU funding agenciesFoundation and EU funding agencies

We are in our 7We are in our 7thth project year and will project year and will complete construction in 2011complete construction in 2011

We are building the largest Neutrino We are building the largest Neutrino Telescope at the geographic South PoleTelescope at the geographic South Pole

The project is on schedule and it has The project is on schedule and it has just begun to produce exciting physics.just begun to produce exciting physics.

http://icecube.wisc.edu/http://icecube.wisc.edu/


44

IceCube IceCube CollaborationCollaboration

Bartol Research Inst, Univ of Delaware, USAPennsylvania State University, USAUniversity of Wisconsin-Madison, USAUniversity of Wisconsin-River Falls, USALBNL, Berkeley, USAUC Berkeley, USAUC Irvine, USA

Univ. of Alabama, USAClark-Atlanta University, USAUniv. of Maryland, USAUniversity of Kansas, USASouthern Univ. and A&M College,

Baton Rouge, LA, USAUniversity of Alaska, Anchorage, USAGeorgia Tech, USAOhio State, USA

Université Libre de Bruxelles, BelgiumVrije Universiteit Brussel, BelgiumUniversité de Mons-Hainaut, BelgiumUniversiteit Gent, BelgiumUniversität Mainz, GermanyDESY Zeuthen, GermanyUniversität Wuppertal, GermanyUniversität Dortmund, Germany

Humboldt Universität, GermanyMPI, Heidelberg, GermanyRuhr-Universität, Bochum, GermanyBonn Universität, GermanyRWTH Aachen, GermanyUppsala Universitet, SwedenStockholm Universitet, SwedenKalmar Universitet, SwedenUniversity of Oxford, UKEPFL, Lausanne, Switzerland

Chiba University, Japan

University of Canterbury, Christchurch, New Zealand

36 collaborating institutions

University ofWest Indies


University of Alberta -Edmonton, Alberta Canada

55

Cosmic Rays: A century old Cosmic Rays: A century old puzzlepuzzle

Victor HessNobel Prize1936

Balloon flights1911-1913

•Power law over many decades

•Origin UncertainCosmic ray spectrumCosmic ray spectrum

Extra Galactic?

Galactic?


South Pole with IceCubeSouth Pole with IceCube

South Pole

runway

Amundsen-Scott South Pole Station

IceCube


77

AMANDA

19 Strings

677 Modules

first data 2005upgoing muon 18. July 2005

IceTop

InIce

Air shower detector

threshold ~ 300 TeV

80-86

Strings,

60 Optical

Modules per

String

Completion:January 2011

2008: 40 Strings (This Analysis)

2009: 59 Strings

2010: 79 Strings

Deep Core

The IceCube Detector


Observing the Universe

Nuclei are easy to detectwith balloon and satellites.Lack directional information and limited to sub-PeV energies.


http://mwmw.gsfc.nasa.gov/mmw_allsky.html

Observing the Universe


1010

Neutrinos as Cosmic Neutrinos as Cosmic MessengersMessengers

Protons: deflected by magnetic fields.

p

Photons: easily absorbed by CMB backgrounds.

γ

Neutrinos: not deflected by magnetic fields. Low interaction cross-section.

ν



Neutrino interactionsNeutrino interactions

35

μ


(NC) X )τν(τν O16)τν(τν

(NC) X)μν(μν O16)μν(μν

(NC) X )eν(eν O16 )eν(eν

(CC) X)(τ τ O16)τν(τν

(CC) X)μ(μ O16)μν(μν

(CC) X )(e e O16 )eν(eν

DDigitaligital OOpticalptical MModuleodule


1414

Sensing Neutrino LightSensing Neutrino Light

Measure arrival time of every Measure arrival time of every photonphoton

2x 300MHz waveform digitizers2x 300MHz waveform digitizers1x 40 MHz FADC digitizer1x 40 MHz FADC digitizerCan trigger in coincidence w/ Can trigger in coincidence w/

neighbor DOMneighbor DOMTransmits data to surface on Transmits data to surface on

requestrequestData sent over 3.3 km twisted Data sent over 3.3 km twisted

pair copper cablepair copper cableKnows the time to within 3 Knows the time to within 3

nanoseconds to all other DOMs nanoseconds to all other DOMs in the icein the ice

Clock stability: 10-10 ≈ 0.1 nsec / secSynchronized periodically to precision of O(2 nsec)

IceCube “Digital Optical Module” (DOM)

Power consumption: 3W

Hamamatsu R7081, 10 inch PMT

33 cm Benthosphere

PMT base

Main board

Flasher Board


IceCube IceCube ConstructionConstruction


1616

Event Event TopologiesTopologies ννμμ produce μ tracks produce μ tracks

– Angular Res ~ 0.7Angular Res ~ 0.70 0

– Eres log(E) ~ 0.3Eres log(E) ~ 0.3 ννe e CC, νCC, νx x NC create showers NC create showers

– ~ point sources, ’cascades’ ~ point sources, ’cascades’ – Eres log(E)=0.1-0.2Eres log(E)=0.1-0.2

ννττ double bang events, others double bang events, others

Muon – IC 40 data

16 PeV ντ simulation350 TeV νe simulationMiami Conference, 12/14-19/2010

Real and Possible ET Neutrino Real and Possible ET Neutrino SourcesSources

The The sunsun

Supernova 1987ASupernova 1987A

Gamma Ray Gamma Ray BurstsBursts

Active Galactic Active Galactic NucleiNuclei

Dark Matter?Dark Matter?


Plethora of PhysicsPlethora of Physics Neutrinos from the sun and SN1987A have Neutrinos from the sun and SN1987A have

been observedbeen observed IceCube can search for SN event with high IceCube can search for SN event with high

sensitivity.sensitivity. We want to search for higher energy We want to search for higher energy

neutrinos and open up a new window to neutrinos and open up a new window to the universe. the universe.

Searches also can be done for neutrino Searches also can be done for neutrino oscillations, wimps, magnetic oscillations, wimps, magnetic monopoles…. monopoles….


The majority of triggers in IceCube are from amospheric muons

We record over 6 x109 muons and 74,000 atmospheric muon neutrinos.

Backgrounds


2020

•Main Background to Astrophysical Search

•Created by high energy cosmic rays

colliding with O and N in the Earth’s

atmosphere

•Conventional (Pions & Kaons) vs. Prompt

(Charmed Mesons)

•Conventional ~ E-3.7 Spectrum

•Prompt ~ E-2.7 Spectrum


Sean Grullon, Ph.D. thesis, UW-Madison, Fall 2010

O

2121

Flux Models and LimitsFlux Models and Limits

Upper Limit on Astrophysical E-2 νμ

E2 < 8.9 x 10-9 GeV cm-2 s-1 sr-1

4.54 < log10(E /GeV) < 6.84

Upper Limit on Astrophysical E-2 νμ

E2 < 8.9 x 10-9 GeV cm-2 s-1 sr-1

4.54 < log10(E /GeV) < 6.84

This Result



Astrophysical Model TestsAstrophysical Model Tests

5σ

5σ

5σ

3σ

This Result



Atmospheric Neutrino Atmospheric Neutrino SpectrumSpectrum



2424

What a Discovery Would Look What a Discovery Would Look Like?Like?

Astrophysical Evidence



Results Results • Diffuse Astrophysical Muon Neutrino Diffuse Astrophysical Muon Neutrino

Upper Limit is Upper Limit is EE22 < 8.9 x 10 < 8.9 x 10-9-9 GeV cm GeV cm-2 -2 ss-1 -1 srsr-1-1

Optimistic Astrophysical models ruled Optimistic Astrophysical models ruled out: No surprises and IceCube is in it for out: No surprises and IceCube is in it for the long haulthe long haul

Atmospheric neutrino spectrum Atmospheric neutrino spectrum measured at high energies from 332.4 measured at high energies from 332.4 GeV to 83.7 TeVGeV to 83.7 TeV

No Evidence for Prompt Atmospheric FluxNo Evidence for Prompt Atmospheric Flux Prompt Atmospheric Models constrained Prompt Atmospheric Models constrained



Point Source Search (IC40)Point Source Search (IC40)

40-string (6 months) All sky search 40-string (6 months) All sky search Livetime: 175.5 days Livetime: 175.5 days 17777 events (6796 up, 10981 down)17777 events (6796 up, 10981 down) Hot spot at Hot spot at α α = 7h 40m= 7h 40m, , δ δ = 15.4°= 15.4° Pre-trial significance of 10Pre-trial significance of 10-4.4-4.4

Post-trials p-value after R.A. scrambling = 61% (all sky) Post-trials p-value after R.A. scrambling = 61% (all sky) Improved signal efficiency, acceptance and background rejection. Improved signal efficiency, acceptance and background rejection.

Northern Sky:ν Background

Southern Sky:μ Background

J. Dumm et al., ICRC 2009 (Lodz)

Preliminary


Gamma Ray Bursts (22 strings)Gamma Ray Bursts (22 strings)

Source stacking: 41 GRBs observed by SWIFT, etc., Source stacking: 41 GRBs observed by SWIFT, etc., summed to estimate a total neutrino fluxsummed to estimate a total neutrino flux

Upper limits set for precursor, prompt neutrino fluxUpper limits set for precursor, prompt neutrino flux Full detector: Full detector: 55σσ GRB neutrino observation GRB neutrino observation within within

2 years (assuming Waxman-Bahcall flux)2 years (assuming Waxman-Bahcall flux)

A. Kappes et al., ICRC 2009 (Lodz)

predicted

90% C.L.


Gamma Ray Bursts, IC-40 and IC-Gamma Ray Bursts, IC-40 and IC-5959(Preliminary)(Preliminary)


• Relative intensity of the cosmic ray event rate: for each declination belt of width 3°, the plot shows the number of events relative to the average number of events in the belt. •First Observation of the Anisotropy for the southern sky.•Abbasi et al., ApJ, 718, L194, 2010

Cosmic ray anisotropy measurement

0o 360o


RelativeRelative Intensity of Cosmic Rays (IC22, Intensity of Cosmic Rays (IC22, IC40IC40 & & IC59IC59) )

Year Rate (Hz) LiveTime(Days) CR Median Energy (TeV)

Median Angular Resolution (degrees)

Number of Events(billion)

2007-IC22 240 ~226 ~19 3 ~4

2008-IC40 780 ~324 ~19 3 ~15

2009-IC59 1300 ~324 ~19 3 ~35

IC40

IC22

0o 360o

IC59

Rela

tive In

tensi

ty

Right AscensionAbbasi et al., ApJ, 718, L194, 2010


IC40 & IC59 results are preliminary

Solar time

Sidereal Time

0o

360o

Observation of the solar dipole effect and the absence of the anti-siderealSignal insures the reliability of the observation.

Anti-sidereal time

Systematic checks (IC59):1-d projection

A1 (10-4) (sidereal)

Φ1(deg) (sidereal)

A1 (10-4)(solar)

Φ1(deg)(solar)

A1(10-4)(anti-sidereal)

Φ1(deg)(anti-sidereal)

7.2±0.1 55.1±0.89 1.7±0.1 90.9±3.6 0.45±0.11 36.7±14.1


Sidereal anisotropy by Tibet Array and Sidereal anisotropy by Tibet Array and IceCubeIceCube

IceCube-5920 TeV

Tibet Array5 TeV

• Data from May 2009-2010• Median angular resolution 3o

• Median Energy resolution 20 TeV• Anisotropy is a continuation of previously

measured large scale anisotropy observed in northern locations.

Relative Intensity


Results SummaryResults Summary First skymap reporting a significant large scale anisotropy in First skymap reporting a significant large scale anisotropy in

the southern hemisphere sky. the southern hemisphere sky. At 20 TeV the anisotropy is in remarkable agreement with At 20 TeV the anisotropy is in remarkable agreement with

previous northren sky measurements.previous northren sky measurements. The result is supported by the observation of solar dipole The result is supported by the observation of solar dipole

effect together with the absence of the anti-sidereal signal. effect together with the absence of the anti-sidereal signal. At higher energies around (400 TeV) the anisotropy At higher energies around (400 TeV) the anisotropy

disappears.disappears. Source for large scale anisotropy is unknown Source for large scale anisotropy is unknown Galactic Environment?Galactic Environment? SNR inducing a large scale anisotropy?SNR inducing a large scale anisotropy?


Supernova Detection with Supernova Detection with IceCubeIceCube


Supernova 1987ASupernova 1987A


Type II SupernovaType II SupernovaOn average, every 30 years or so in our galaxy a massive star with M > 8M explodes

Gravitational instability due to C, O, and Si fusion into a Fe – Ni core

Gravity overcomes the electron pressure and collapsebegins; nuclear densities are reached with a core radius of R ~ 10 km, with E = GM~ 10 km, with E = GM22/R ~/R ~ 10105959 MeV MeV

Neutrinos are trapped in the neutrinosphere and materials bounce, cooling of the neutron star by neutrino emission, shock wave and explosion Ekin ~ 0.01 E.~ 0.01 E.

99% of the energy is carried off by neutrinos!99% of the energy is carried off by neutrinos!Miami Conference, 12/14-19/2010

Totani et al., (1998)Totani et al., (1998)


Neutrino Spectra from SN

SN87A EventsSN87A EventsIMB & KamiokaIMB & Kamioka

IMBI

KAMI


Electron anti-neutrino Electron anti-neutrino spectrumspectrum

Takahashi and Sato, hep-ph/0905070v3, Prog.Theor. Phys. 109 (2003) 919-931




XY Hit distribution for SN positrons, i3geant , XY Hit distribution for SN positrons, i3geant , average DOM QE, 27% higher for DeepCore average DOM QE, 27% higher for DeepCore

(AHA Ice Model)(AHA Ice Model)


ZX Hit distribution for SN positrons, ZX Hit distribution for SN positrons, i3geant , average DOM QE, 27% higher for i3geant , average DOM QE, 27% higher for

DeepCore (AHA Ice Model)DeepCore (AHA Ice Model)


IceCube SN Sensitivity IceCube SN Sensitivity For a SN with 10 M at a distance of 10 kpc, the For a SN with 10 M at a distance of 10 kpc, the

dominant neutrino reaction isdominant neutrino reaction is ννeep p ne ne+ + with a flux-integrated CC cross with a flux-integrated CC cross section of:section of:

σσ = = 0.24 x 10 0.24 x 10-40-40 cm cm2 2 (Vogel and Beacom, Struma and (Vogel and Beacom, Struma and Vissani, Llewellyn and Smith) at T = 5 MeVVissani, Llewellyn and Smith) at T = 5 MeV

The SN detection method in IceCube is based on an The SN detection method in IceCube is based on an overall count-rate increase in the DOM’s. overall count-rate increase in the DOM’s.

We expect a sensitive range of ~ 60 kpc (LMC)We expect a sensitive range of ~ 60 kpc (LMC)


IceCube SN Sensitivity IceCube SN Sensitivity

Recently, our Geant MC indicates that a Recently, our Geant MC indicates that a trigger based on two-DOM coincidence trigger based on two-DOM coincidence may be possible.may be possible.

This method will substantially reduce the This method will substantially reduce the background and will dramatically background and will dramatically increase the sensitivity of the IceCube increase the sensitivity of the IceCube detector to well beyond the LMC.detector to well beyond the LMC.


ConclusionsConclusions IceCube is almost complete and will be fully IceCube is almost complete and will be fully

operational soon (78 + 8 DeepCore). operational soon (78 + 8 DeepCore). Data has been analyzed for diffuse neutrinos, Data has been analyzed for diffuse neutrinos,

anisotropy, GRB’s, point sources …anisotropy, GRB’s, point sources … No surprises yet, but with the full detector No surprises yet, but with the full detector

operating, we are eager to analyze future data operating, we are eager to analyze future data and ever hopeful!and ever hopeful!

SN detection capability of IceCube looks ever SN detection capability of IceCube looks ever more promising. more promising.

Stay tuned!Stay tuned!


AcknowledgementAcknowledgement

We gratefully We gratefully acknowledge the acknowledge the funding of our project at Southern from funding of our project at Southern from a National Science Foundation, Major a National Science Foundation, Major Research Equipment grant through the Research Equipment grant through the University of Wisconsin Board of University of Wisconsin Board of Regents. Regents.


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IceCube : Status and Results