XIX European Cosmic Ray SymposiumFirenze (Italy)

http://amanda.uci.edu http://icecube.wisc.edu

Neutrino Astronomy and Cosmic Raysat the South Pole

Latest results from AMANDA and perspectives for IceCube

Paolo Desiatidesiati@icecube.wisc.edu

University of Wisconsin – Madison

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

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, USAIAS, Princeton, USAUniversity of Kansas, USASouthern Univ. and A&M College, Baton Rouge

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

Universidad Simon Bolivar, Caracas,Venezuela

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

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

Uppsala Universitet, SwedenStockholm universitet, SwedenKalmar Universitet, SwedenImperial College, London, UKUniversity of Oxford, UKUtrecht University, Utrecht, NL

Uppsala Universitet, SwedenStockholm universitet, SwedenKalmar Universitet, SwedenImperial College, London, UKUniversity of Oxford, UKUtrecht University, Utrecht, NL

Chiba University, JapanChiba University, Japan

University of Canterbury, Christchurch, New Zealand

University of Canterbury, Christchurch, New Zealand

Who are we ?

Amundsen-Scott South Pole Station

South PoleDome

Summer camp

AMANDA

road to work

1500 m

2000 m

[not to scale]

Where are we ?

PMT noise: ~1 kHz

AMANDA-B10(inner core of AMANDA-II)

10 strings302 OMs

Data years: 1997-99

Optical Module

“Up-going”(from Northern sky)

“Down-going”(from Southern sky)

AMANDA-II19 strings677 OMs

Trigger rate: 80 HzData years: >=2000

PMT looking downward

AMANDA

IceCube

IceTop

IceCube80 strings

60 OMs/string17 m vertical spacing

125 m between strings

IceTop160 tanks

frozen-water tanks2 OMs / tank

First year deployment (Jan 2005) 4 IceCube strings (240 OMs)

8 IceTop Tanks (16 OMs)

10” Hamamatsu R-7081

1200 m

IceTop Tank deployed in 2004

Event detection in the iceO(km) long tracks

~15 m

cascades

Longer absorption length → larger effective volume

AMANDA-II

trackspointing error : 1.5º - 2.5º

σ[log10(E/TeV)] : 0.3 - 0.4

coverage : 2Cascades (particle showers)

pointing error : 30º - 40º

σ[log10(E/TeV)] : 0.1 - 0.2

coverage : 4

cosmic rays (+SPASE)combined pointing err : < 0.5º

σ[log10(E/TeV)] : 0.06 - 0.1

Nucl. Inst. Meth. A 524, 169 (2004)

event reconstruction by Cherenkov light timing

South Pole ice: the most transparent natural

medium ?

a neutrino telescope

0.65o(E/TeV)-0.48

(3TeV<E<100TeV)

abs> ~ 110 m @ 400 nm

sca> ~ 20 m @ 400 nm

ν astronomy : physics goals

Bottom-Up scenariocosmic acceleratorp + (p or ) + X e , + X

• Protons which escape are bent => cosmic rays

• Photons which escape are absorbed above 50 TeV

• Neutrinos escape

a neutrino telescope• good pointing resolution• good acceptance

AMANDA

IceCube

Array

requires ~ km3 scale

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/Down EnergySource

directionArrival

timeCount rates

Atmospheric ν ×Diffuse ν,

Cascades,

UHE events× ×

Point sources:

AGN, WIMPs × × ×GRB × × × ×

Supernovae ×

Preliminary

ν astronomy : background

Atmospheric background & calibration beamFirst energy spectrum > 10 TeVBlobel regularized unfolding

• Protons which escape are bent => cosmic rays

• Photons which escape are absorbed above 50 TeV

• Neutrinos escape

Preliminary

Expected high energy flux

… in this talk

telescope capability

search of high energy from extra-terrestrial steady point sources

Cosmic Ray measurements

telescope : point source search

Detection of from discrete steady bright or close sources (AGN, …)• cosmic ray background rejection• good pointing resolution• bin search optimization versus a given signal ( E-2)

detectorpointing

resolutionbin search

radius effective area

AMANDA-B10 3° ↑ -5.8° →5°5° (min)

10°10° (max)~0.01 km2 (@ 10 TeV)

AMANDA-II 1.5° ↑ -2.7° →3.6°3.6° (min)

8.8°8.8° (max)~0.025 km2 (@ 10 TeV)

IceCube ~0.7° (> 10 TeV) ~ 1°~ 0.8 km2 (> 10 TeV)

~1.2 km2 (> 100 TeV)

AMANDA-B100o

0o

0o

0o

effective area

1 m2

AMANDA-II

declination 0o

90o

↑ 2

telescope : point source search

Average upper limit = sensitivity (δ>0°)(integrated above 10 GeV, E-2 signal)

(*) optimized for E-2, -3 signal

1997 : Ap.J. 583, 1040  (2003)

2000 : PRL 92, 071102 (2004)

IceCube : Astrop Phys 20, 507 (2004)

ave

rag

e fl

ux

up

per

lim

it [

cm-2s-1

]

sin

AMANDA-B10

AMANDA-II

Sensitivity independent of direction

*

lim 0.68·10-8 cm-2s-1

ave

rag

e fl

ux

up

per

lim

it [

cm-2s-1

]

sin

AMANDA-B10

AMANDA-II

IceCube 1/2 year

*

Preliminary

declination 0o

90o

telescope : point source search

2000-2003

3369 from northern hemisphere

3438 expected from atmosphere

Preliminary

Search for clustering in northern hemisphere• compare significance of local fluctuation to atmospheric expectations• un-binned statistical analysis• no significant excess

~92%

Maximum significance 3.4

compatible with atmospheric

also search for neutrinos from unresolved sources

Cosmic rays spectrum

1 km

2 km

Cosmic rays spectrum

SPASE-AMANDA

combined angular resolution ~ 0.5o

absolute pointing calibration < 1o

S(30) Ne particle density at 30m from core

K50 energy lost in AMANDA (E>500GeV )

Nlateral distr func at 50m from core

K50,S(30) (N, Ne) (Energy, Mass)

SPASE as muon survey of AMANDA

SPASE-2 + AMANDA~1/7000 km2 sr for coincident tracksIceTop + IceCube1/3 km2 sr for coincident tracks

IceTop-IceCube

VETO

All downward events E > 300 TeV with trajectories inside IceTop

Larger events falling outside

CALIBRATION

of angular response and with tagged

Expect ~100 tagged air showers/day with multi-TeV m’s in IceCube

IceTop as muon survey of IceCubez

S(30)

K50

Cosmic rays composition

• spectra steeper because of smaller fluctuations at higher energies• mean values shifted by fluctuations• error in mass determination

Fluctuations@ knee are smaller@ South Pole

IceTop/IceCube energy extension

e.g SPASE

e.g. KASCADE

1015 eV

AMANDA-B10

Normalize to direct measurements

<ln A> = 2 (JACEE/RUNJOB)

SPASE-AMANDA

Primary energy resolution ~ 0.07 in log10(Eprim)CR composition measured in 0.5 - 6 PeV

IceTop-IceCubeCovers sub-PeV to EeV energiesImprove energy resolution

Cosmic rays composition

In press

Astroparticle Physics

mass-independent high resolution primary energy measurement

probing relative change of muonic energy to electromagnetic

energy in the showermethod robust against systematic

uncertainties

data are consistent with anincrease of cosmic ray mass

composition at the knee, between 500 TeV and 5 PeV.

Direct measurements

Summary

• AMANDA-II is collecting data and increasing statistics. Has reached good sensitivity as neutrino telescope (point sources search)

• SPASE-2/AMANDA-B10 indicates increase of CR mass composition @ knee• AMANDA-II is improving other results by tightening constraints on models :

• Neutrinos from SN• Neutrinos from WIMP annihilations (Earth and Sun)• Search for neutrinos in coincidence with GRB’s• Search for neutrinos e from unresolved diffuse sources• Search for UHE/EHE extra-galactic neutrinos• CR spectrum and composition

• IceCube/IceTop will significantly improve astrophysics in energy range and resolution

• IceCube will be a powerful all-flavor neutrino detector (particle physics)• IceTop will open the CR measurements up to ~ EeV with high resolution

• AMANDA will overlap the lower energy tail of IceCube sensitivity

“The “ @ South Pole

thank you

Polar ice optical properties

Measurements:►in-situ light sources►atmospheric muons

Average optical ice parameters:

abs ~ 110 m @ 400 nmsca ~ 20 m @ 400 nmatt ~ 17 m @ 400 nm

Scattering

bubbles

dust

Absorption

dust

ice

back

Mediterranean sea optical properties

Average optical ice parameters:

abs ~ 63.3 m @ 440 nmsca ~ 80.8 m @ 440 nmatt ~ 35.5 m @ 440 nmback

abs

att

Average values 2850÷3250 m

AMANDA : neutrino limits

diffuse (B10)

cascades/3UHE/3

Unfolded(last bin)

constraint models

• Upper limits on diffuse ET neutrino fluxes• Atmospheric ν energy spectrum• Cascade analysis• Ultra High Energy ν search

back

Antares 1 yr

IceCube 1 yr

AMANDA : Aeff

AMANDA-B10

AMANDA-II

back

AMANDA : K50

The entire high energy (> 500 GeV) muon bundle is measured over a

large volume

The light output from all muons issampled over 500 m length and 150 m

laterally

K50 is the measure of muon energylost in a large volume

back

AMANDA : K50 normalization

back

Apanasenko et al., Astrop. Phys. 16 , 13 (2001)

CR composition: fluctuations

back

SPASE/IceTop

KASCADE(-Grande)

CR composition: fluctuations

back

J. Van Buren

Diploma ThesisKarlsruhe, 2002

back

IceTop : 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.

IceTop

back

Rates of contained coincident events

• 125 m grid, km2 air shower array at 690 g/cm2

• Ethreshold ~ 300 TeV for > 4

stations in coincidence

• Useful rate up to ~ EeV

• Total rate 1-2 kHz

• Median Eprimary = 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)

IceTop : EeV detection

back

Penetrating muon bundle in shower core

Incident cosmic-ray nucleus

Threshold ~ 1018 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)

Neutrino flavor identification

back

Neutrino flavor

Log(ENERGY/eV)

12 18156 219

e

e

supernovaeFull 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

to the end

IceCube : Aeff & resolution

Galactic center

back

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

IceCube : simulated track events

back

Eµ=6 PeV, 1000 hitsEµ=10 TeV, 90 hits

IceCube : sensitivities

Diffuse sensitivity Point source sensitivity

back

IceCube : DOM Mainboard

back

2xATWD

FPGA

Memories

HV Board Interface

CPLD FPGA (Excalibur/Altera) reads out the ATWD handles communications time stamps waveformssystem time stamp resolution 7 ns wrt master clock

FPGA (Excalibur/Altera) reads out the ATWD handles communications time stamps waveformssystem time stamp resolution 7 ns wrt master clock

oscillator (Corning Frequency Ctl)running at 20 MHz

maintains df/f < 2x10-10

2 four-channel ATWDsAnalog Transient Waveform Digitizerslow-power ASICsrecording at 300 MHz over first 0.5mssignal complexity at the start of event

2 four-channel ATWDsAnalog Transient Waveform Digitizerslow-power ASICsrecording at 300 MHz over first 0.5mssignal complexity at the start of event

Dynamic range 200 p.e./15 ns 2000 p.e./5 msenergy measurement (TeV – PeV)

Dead time < 1%

fast ADC recording at 40 MHz over 5 msevent duration in ice

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