xix european cosmic ray symposium firenze (italy) ://icecube.wisc.edu neutrino astronomy and cosmic...
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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
back
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