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Neutrino Astronomy with AMANDA
Steven W. BarwickUniversity of California-Irvine
SPIE Conference-Hawaii, 2002
Outline of Talk
•Science of HE Neutrino TelescopesPoint SourcesDiffuse Sources (up and down)GRBsWIMP annihilations in earth and sun
• Future developments in detector technology
Messengers of Astronomy
• The neutrino window begins at energies above 1013 eV
• Era of multi-messenger astronomy
Detection Method for
• Cherenkov photons are detected by array of PMTs
• Tracks are reconstructed by maximum likelihood method of photon arrival times.
1
2 3
4
5 6
South Pole
AMANDA-II
Dome
Skiway
The AMANDA-II Collaboration
• Bartol Research Institute, University of Delaware• BUGH Wuppertal, Germany• Universite Libre de Bruxelles, Brussels, Belgium• DESY-Zeuthen, Zeuthen, Germany• Dept. of Technology, Kalmar University, Kalmar, Sweden• Lawrence Berkeley National Laboratory, Berkeley, USA• Dept. of Physics, UC Berkeley, USA • Dept. of Physics and Astronomy, UC-Irvine, USA• Institute of Physics, University of Mainz, Mainz, Germany• University of Mons-Hainaut, Mons, Belgium• Fysikum, Stockholm University, Stockholm, Sweden• Dept. of Physics, University of Alabama, USA• Vrije Universiteit Brussel, Brussel, Belgium• Dept. Fisica, Univ. Simon Bolivar, Caracas, Venezuela• Dept. of Physics and Astronomy, Penn State University, College Station, USA• Dept. of Astronomy, Dept. of Physics, University of Wisconsin, Madison, USA• Physics Department, University of Wisconsin, River Falls, USA• Division of High Energy Physics, Uppsala University, Uppsala, Sweden• Dept. of Physics, Imperial College, London, UK
Institutions: 8 US, 10 European, 1 South American
AMANDA-II
depth
The AMANDA Detector
Super-K
• Early photons are red, late photons are blue. More photons are larger circles
• Bottom of array is toward center of earth
• Event is clearly traveling in the upward direction
AMANDA -event
Building AMANDA
Drilling Holes with Hot Water
The Optical Module
Optical Properties of Ice
Sensitivity to cascades and EHE physicsdemonstrated with in-situ sources
In-situ light sourceSimulated light source
Scatteringcoefficient(1/m)vs. depth
Detailed measurement of optical properties strong light scattering dust layers low absorption (in particular in UV !!)
TriggerLevel
After BGrejection
up horizon
A-II
B-10
dramatically increased acceptancetowards horizon
Nearly horizontal event
(experiment)
AMANDA-II
Arb
. uni
ts
Physics Reach of AMANDA-II
0
50
100
150
200
-1 -0.8 -0.6 -0.4 -0.2 0
Aeff
[ x10
3 m2]
Cos(theta)
E = 10 TeV
- Am II Trigger
- Am II Point Cuts
- 10 Am B Point Cuts
- Am II GRB Cuts
10-10
10-8
10-6
10-4
102 103 104 105 106
E2
(dN/dE ) [GeVcm
-2s
-1]
E( )GeV
- (3 )AMANDA II yr
- 10 ( 97)AMANDA B '
IceCube3 273C
Crab
AGN Core
501 (Mk =γ)
. Atm
Mk-501
Search for from TeV γ sources
Milagrito all-sky search sets limit at > 1 TeV: 7-30 10-7 m-2 s-1, ( E-2.5)
Amanda probes similar flux if /γ > 1
Sensitivity to point flux E2 F ~ 5 10-8 GeV cm-2 s-1 sr-1
Area depends on physics
0
0.1
1
10
-90 -60 -30 0 30 60 90
Φ
(cm-2sec-1
) 10x
14
( )Declination degrees
AMANDA-B10
Super Kamiokande MACRO
AMANDA-II (expected sensitivity)
Mk-501 /γ ~ 1
Point Source Limits
northern sky
southern sky
Submitted to ApJ: astro-ph/0208006
1 km
2 km
SPASE air shower array
calibration of AMANDA angular resolution and pointing !
confirms predicted angular resolution Amanda-B10 ~ 3° (due to tails, best fit by two component gaussian)
absolute pointing < 1.5°
Unique:
Analysis Checks
MC of Backgrounds Systematic Uncertainty
Atmospheric Neutrinos, 97 data
vertically up horizontal AMANDA sensitivity understood down to normalization factor of ~ 40% (modeling of ice ...)
~ 300 events
cos()
Ahrens. et al. PRD(2002), astro-ph/0205109
• Improved coverage near horizon
• In 6o6o bin, for E-2 spectrum, and 10-8 cm-2 s-1 flux:
~ 2 signal
~1.5 background
0.40.61ES 1959+650
1.43.5SS433
0.50.7Cass. A
0.61.2Crab
0.50.75Markarian 501
0.50.75Markarian 421
(10-8 cm-2 s-1)muon (10-15 cm-2 s-1)Source\Sensitivity
Point Sources AMANDA-II
Event times scrambled for blind analysis purposes.
Equatorial coordinates: declination vs. right ascension.
~1129 events
Projected sensitivities calculated using background
levels predicted from 3 years of Am-II data on tape.
From 2000
Diffuse flux: Am-B10 limit
E2 Φ < 0.9 10-6 GeV-1 cm-2 s-1 sr-1
„AGN“ with 10-5 E-2 GeV-1 cm-2 s-1 sr-1
solid: experiment
dotted: atmos.
1st draft, to be subm. to Astr.Part.Phys.
10 km
AMANDA-II
High EnergyNeutrino
Micro-Black Hole
EHE (E 1016 eV) Search
• Main background: muon “bundles”
– Comparable NPMT but smaller Nγ
• Calibrate with in-situ N2 laser
• Still evaluating systematic uncertainties
EHE events very bright; many PMTs detect multiple photons
At EHE energies, expectonly events near horizon
R 10 km
Preliminary Limit
vert
ical
Diffuse upDiffuse down
3 months B10
AMANDA-II expected
Diffuse fluxes: theoretical bounds and experimental limits
atmo
sph
eric Neu
trino
s
W&B W&B
MPRMPR
DUMAND test string
FREJUS
NT-200+
AMANDA-II
IceCube (~2012)
NT-200
AMANDA-B10
MACRO
down
Big Question:Where do prompt muons from
CHARM come in?
GRB Analysis
• Search strategies1. Short duration (T90 < 1 s), composite2. All duration, composite3. All duration, maximize on single burst sensitivity
x
x
energy
x
x
x
up/down time
xPoint Sources: AGN,WIMPs
Diffuse ,
EHE events
Atmospheric
xx xxGRBs
source direction
GRB Analysis (‘97) - 88 BATSE bursts
1 hour 1 hour16 s
BKG - off time BKG - off timeon time
T90 of GRB burstBackground cuts can beloosened considerably high signal efficiency
Composite
AMANDA-II GRB Analysis (‘00) AMANDA-II GRB Analysis (‘00)
Check stability and maximize sensitivity for desired BG rejection
58 bursts (triggered and non-triggered)Feb-May 2000
Stability
RA-DEC
AMANDA-II GRB Analysis (‘00) AMANDA-II GRB Analysis (‘00)
Compute probability to get observed events froim random fluctuation
10-2
10-1
100
0 0.5 1 1.5 2
Occurance Fraction
-log(P)
Random Fluctuation of BG No evidence for
neutrino emission by any GRB
GRBs
Occ
urre
nce
Fra
ctio
n
AMANDA-II GRB Analysis (‘00) AMANDA-II GRB Analysis (‘00)
The effective area of AMANDA-II is enormous, nearly 0.06km2
For W-B flux, the most probable
detected energy is ~105 GeV
Aef
f(km
2 )
Log(EGeV)
WIMP annihilation in sunWIMP annihilation in sun
Freese, ’86; Krauss, Srednicki & Wilczek, ’86Gaisser, Steigman & Tilav, ’86
Silk, Olive and Srednicki, ’85Gaisser, Steigman & Tilav, ’86
Sun
Earth
Detector
velocitydistribution
scatt
capture
annihilation
interactions
int. int.
Limits on WIMP annihilation in Earth
WIMP annihilationat Earth’s center
MSSM/DarkSUSY
AMANDA
Earth
astro-ph/0202370, to appear in PRD
(Area approximate)
soft
hard
• Disfavored by recent direct
searches
2002 real time analysis
event June 6
Daily transmission ~ 1 GB via satelliteFull data to tape (available next polar summer)
Monitoring shifts in home labs
From 02/03:Iridium connection for supernova alarm
MPR[1.5]
W&B
20% Amanda II cascade limit (Y2K)
nγ<1
nγ>>1
0.50Prompt charm
(RQPM)
0.15e (CC), e+ (NC)
Predicted events in 100% of 2000 data
Atmospheric ’s
3.2Φ+
= 10-6 E-2 GeV
cm-2 s-1
5.5Φe+e
= 10-6 E-2 GeV
cm-2 s-1
Predicted events in 100% of 2000 data
Astrophysical ’s
Cascade limits
AMANDA begins to challenge model predictions, Prel. diffuse limit is below “weak” theoretical boundDiscovery potential
Preliminary results from AMANDA-II GRB, Atmospheric NeutrinosPoint sources: soon
Trans-GZK events revived interest in EeV physicsExcellent sensitivity to EeV neutrinos
Promising future:Real-time data analysisNew DAQ with full waveform readout>2 more years of AMANDA-II data on tapeThere is a great deal more to do!
Summary and Outlook