Neutrino Astronomy at the South PoleStatus of AMANDA Experiment

Paolo Desiati

University of Wisconsin- Madison

for the AMANDA Collaboration

La Thuile, Valle d’Aosta (Italy)

March 10, 2003

Neutrino Astronomy at the South Pole – p.1/30

AMANDA CollaborationBartol Research Institute, University of DelawareDept. of Physics, University of California BerkeleyDept. of Physics, University of California IrvineDept. of Physics, Pennsylvania State UniversityDept. of Physics, University of Wisconsin - MadisonDept. of Physics, University of Wisconsin - River FallsLawrence Berkeley Laboratory, BerkeleyDept. of Physics, University of Kansas - Lawrence

Dept. of Physics, University of Alabama - Tuskaloosa

Universidad Simón Bolvár, Caracas

ULB - IIHE, BusselsVUB Brussels

Université de Mons-Hainaut, MonsImperial College, LondonDESY-Zeuthen, ZeuthenMainz Universität, Mainz

Wuppertal Universität, WuppertalDept. of Physics Stockholm University, StockholmDiv. of High Energy Physics, University of Uppsala, Uppsala

Dept. of Technology, University of Kalmar, Kalmar

Neutrino Astronomy at the South Pole – p.2/30

AMANDA-II Experiment

� 19 strings

� 677 Optical Modules (OM)

� 200 meters diameter

� 500 meters tall

� completed in 1999

� 1997-99 AMANDA-B10� 10 strings, 300 OM

Neutrino Astronomy at the South Pole – p.3/30

AMANDA-II Location

Neutrino Astronomy at the South Pole – p.4/30

AMANDA-II Deployment

� drill 2,000 m holes with�� � �

water

� hole diameters is

� � � �� but varies withdepth to correct for icetemperature profile

� drilling time is

�� � � �

� deploy strings withoptical sensors

� deployment time is �

� � �

Neutrino Astronomy at the South Pole – p.5/30

Why Neutrinos ?

Astronomical MessengersAstronomical MessengersNeutrinos

Photons

20 221816141210 11 13 19 2117

Log(E) (eV)

15

Protons

TeV

PeV

EeV

Sun

,S

N19

87A

Neutrino Astronomy at the South Pole – p.6/30

Detection Principle

�

Cherenkov photons are detectedby PMTs

�

tracks are reconstructed by

maximum likelihood method of

photon arrival times

�cascades have a sphericaltopology

�need specific reconstruction

technique

� � ice properties

� � array geometry

Neutrino Astronomy at the South Pole – p.7/30

Ice and Geometry

10-2

10-1

300 350 400 450 500 550 600

1/50

1/33

1/25

1/201/161/141/121/111/10

1/334

1/250

1/2001/1671/1431/1251/1111/100

κ = 1.07 ± 0.05MCdust = 6.95 ± 1.89

κ = 1.14 ± 0.02MCdust = 3.79 ± 0.45

wavelength [nm]

be(λ) = (λ/532) -0.84be(532)

abso

rptio

n co

effi

cien

t [m

-1]

EUVRMYAG1760 m1690 m

effective scattering coefficient [m-1]

(z-1730

m)

[m]

-350

-300

-250

-200

-150

-100

-50

0

50

100

150

200

250

0.01 0.02 0.03 0.04 0.05 0.06 0.07

�

ice optical properties nonhomogeneous�

scattering/absorption varies withdepth and

�

�

average properties at � �� ��� �

�� � � � absorption�� � � effective scattering

�in-situ calibration lasers usedalso for geometry/timecalibration�geometry precision is � ��� � �

�

photon arrival time precision ��� �

Neutrino Astronomy at the South Pole – p.8/30

Cosmic Ray Muons

Atmospheric Muons Angular Distribution

cosΘ

Φµ

(cm

-2se

c-1sr

-1)

10-9

10-8

10-7

0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1

� �! " � �� #%$ &

in average�

good quality tracks�

resolution

'( )� � � *

� �� � +

ice models uncertainty

�

Data/MC normalized tovertical bin�MC uses CORSIKA withWiebel-Sooth primary CR

�

curves from Klimushin et al.Phys.Rev.D, 64, 014016�

predictions with experimen-tally measured parameters

Neutrino Astronomy at the South Pole – p.9/30

Muon/Primary Energy Spectrum

�

CORSIKA with Wiebel-Sooth CRspectrum�, - . . )� � /0 1 ��� �2

from MC�

primary cosmic ray spectrum�, 354 )� � 6� 1 � � � �

�

use of regularized unfolding�

sea-level single muon spectrum�, 3 4 )� � 6� 1 � � � 6

Neutrino Astronomy at the South Pole – p.10/30

CR Composition

Etrue = 1 PeV - 10 PeVEntries 1798Constant 3057.Mean -0.3207E-01Sigma 0.6900E-01

log(Ereco)-log(Etrue)

0

500

1000

1500

2000

2500

3000

3500

-0.6 -0.4 -0.2 0 0.2 0.4 0.6

even

ts

�

SPASE-AMANDA coincidence

�

SPASE S30 ( 798 :2 � � ; )�

AMANDA K50( < => ?@ : � � � ; )

�strong correlations with

=

and�BAC�

SPASE/AMANDA resultnormalized at first point

� � 6 +

resolution in

�BA C in 1-10PeV

Neutrino Astronomy at the South Pole – p.11/30

Neutrino Analysesup/down energy source arrival count topology

direction time rate

Atm D�E F

Diff & EHE D F F

Point Sources:

F F FAGN,WIMPS

GRB

F F F F

Cascades

F F F F

Supernovæ

F

L1 [OM cleaning, first guess fit, loose angular cut]

L2 [max likelihood fit, bayes fit, tighter anguar cut, direct hits]Neutrino Astronomy at the South Pole – p.12/30

Atmospheric G in AMANDA-B10

cosθ

Data

Atmospheric ν MC

0

5

10

15

20

25

30

35

40

-1 -0.9 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0

dN/dcosθ

� in 130.1 days lifetime

�

MC normalized to data at high cut level

� H$I J K LM Nevents

� H �O K L PQ RS

events

� Background contamination

� T UWV X M Y

� pointing resolution

S[Z L �

� \ \ ]!^ _ ` a D ` S[Z N bc^ _

�

Physical Review D, 66, 012005 (2002)�

Nature, Vol 410, 22 Mar 2001, 441-443

Neutrino Astronomy at the South Pole – p.13/30

Atmospheric G in AMANDA-II

0102030405060708090

100

-1 -0.8 -0.6 -0.4 -0.2 00

102030405060708090

100

-1 -0.8 -0.6 -0.4 -0.2 0

0102030405060708090

100

-1 -0.8 -0.6 -0.4 -0.2 0

cosθ cosθ

cosθ cosθ

0102030405060708090

100

-1 -0.8 -0.6 -0.4 -0.2 0

Exp Data 1226 Exp Data 933

Exp Data 709

MC Data 737 MC Data 674

MC Data 610 MC Data 519Exp Data 527

� pure d sample

� easier to obtain than B10

� only 3 cuts e d fg

� 197 days in 2000

� goodunderstanding ofatmospheric dih� j " 3 < � �

� kcl 3 @ � � � *

�

high fit quality�

uniform lightdeposition along thetrack�

effect of cuttightening

Neutrino Astronomy at the South Pole – p.14/30

Diffuse Gnm in AMANDA-B10

log10(Eν) [GeV]

even

ts

10-5 E-2 νµatmos. νµ

pass initial cuts

passallcuts

10-1

1

10

2 3 4 5 6 7

log10(Eν) [GeV]

log 10

E2 Φ

ν(E

) [c

m2 s

-1 s

r-1 G

eV]

Atmosphericneutrinos

SS QC pred.A-B10 lim.

Charm DA-B10 lim.

Charm Dpred.

MACRO E-2 νµ

Baikal E-2 νe

Frejus νµ (diff. at Eν=2.6 TeV)

AMANDA-B10 E-2 νµ

AMANDA-B10 E-2 νe

-7

-6.8

-6.6

-6.4

-6.2

-6

-5.8

-5.6

-5.4

-5.2

-5

3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8

�

search for HE D E from unresolved sources�

assumes harder spectrum�o prq )� s� �t uwv �t x O �t x �t y �z t y

�

background (atm D E ) suppressed by energy cuts(nch)�

90% of events in/ {$ & < � p <� |}$ &

�

limit(no sys uncertainty)�o ~� � < 6� 6 s� �t � s �t x O �t x �t y �z t y #%$ &

�limit(with 25% sys uncertainty)�o ~� � < 0 � � s� �t � s �t x O �t x �t y �z t y #%$ &

�submitted to Physical Review Letters

Neutrino Astronomy at the South Pole – p.15/30

Diffuse Gm in AMANDA-II

�o pq )� s� �t �v �t x O �t x �t y �z t y

�

90% of events in� � {$ & < � p <� � |}$ &

�

90% CL Feldman-Cousins average upperlimit�

optimal energy cut at nch=93�

sensitivity for 1y� � 6 s� � t �v �t x O �t x �t y �z t y

� s 4.5 better than AMANDA-B10�

still on-going analysis

Neutrino Astronomy at the South Pole – p.16/30

Point Sources in AMANDA-B10

�

Ap J, 583, 1040 (2003)

84

9 1 3 2

6

57

10

1 - Mkn5012 - Mkn4213 - NGC41514 - 1ES23445 - 3C66A

6 - 1ES1959+650 7 - Crab Nebula 8 - Cassiopeia A 9 - Cygnus X-310 - Geminga

-1.5

-1

-0.5

0

0.5

1

1.5

-3 -2 -1 0 1 2 3

�median pointing resolution� )2 � � *

�northen hemisphere sky dividedin 154 bins ( �� � * s� � *

)

�

looser cuts than atmospheric D �

higher sensitivity� H$ I J K � X U

events

Neutrino Astronomy at the South Pole – p.17/30

Point Sources in AMANDA-II�

cut optimization at eachdeclination band (

� �� � 2 *

)�

good sensitivity close to horizon�

10% BG contamination in

� @ � *

� j8�� ) / � 6

events in

� @ � *

�

northen emisphere divided in 300bins ( � 6 * s 6 *

)�

no significant excess observed

24h 0h

°-90

°90 1555 events

θ90 100 110 120 130 140 150 160 170

even

tN

20

40

60

80

100

120

Data

MCνAtm

Neutrino Astronomy at the South Pole – p.18/30

Point Sources in AMANDA-II

10-4

10-3

10-2

10-1

11010 2

0 1 2 3 4 5 6

10-3

10-2

10-1

1

10

10 2

0 1 2 3 4 5 6

10-4

10-3

10-2

10-1

11010 2

0 1 2 3 4 5 6

10-3

10-2

10-1

1

10

10 2

0 1 2 3 4 5 6

Significance Distributions

ξ

n. o

f bin

s (δ1

0O)

ξn.

of b

ins (

δ10O

)

ξ

n. o

f bin

s (δ1

0O)

ξ

n. o

f bin

s (δ1

0O)

ξ

n. o

f bin

s (δ1

0O)

10-4

10-3

10-2

10-1

1

10

10 2

0 1 2 3 4 5 6

Significancedistribution inall-sky gridsearch

Neutrino Astronomy at the South Pole – p.19/30

Point Sources in AMANDA-II

Source

�

1997 2000

Crab

L L �

4.2 2.1

Mkn 421

S �Z L �

11.2 3.1

Mkn 501

S QZ � �9.5 1.6

Cygnus X-3N XZ U �

4.9 3.1

Cass. AU �Z � �

9.8 1.0

Table 1: Sensitivities in

�� � ��� � � ���� � � �

Neutrino Astronomy at the South Pole – p.20/30

WIMPS from the center of Earth

� � vertical up-going muons�

high reco quality tracks�

8-dim cut to separate signal/bg�

simulation of�9� )� � ��� � � � � #%$ &

�6 annihilation channels

��9� �2 � +

��� � � ��� 2 +

�

no excess observed

�

Physical Review D, 66, 032006(2002)

Neutrino Astronomy at the South Pole – p.21/30

Gm from GRB

GRB trigger timet=0

10 sec−1 hour +1 hour

BG from off−time BG from off−time

(T90)�

AMANDA-B10�

273 BATSE triggers in 97-99�

binsearch

� � 6� � � *

�

high quality track fit

�

AMANDA-II�

44 BATSE triggers in 2000�

binsearch

� <� � *

�

high quality track fit�

smooth hits distribution along track

� no excess found in anyanalyzed year

Neutrino Astronomy at the South Pole – p.22/30

Cascades in AMANDA-B10

log10(Eν/GeV)

E2 Φ

[

GeV

s-1

sr-1

cm

-2 ]

AMANDA-II νe

PRELIMINARY

νe νµ

AMANDA-B10 νµ

AMANDA-B10 νe

BAIKAL νe

10-7

10-6

3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8

� ���� : D8 ; <

/� � s� � t � s �t x #%$ & O �t x �t y �z t y

� � {$ & < � p <2 � � {$ &

�

cascades from em/hadronicshowers� D8 , D�  CC+NC� D¡E NC

�

vertex position� '¢z � �� � �

�energy resolution� '£}¤ ¥ : �§¦ -� ¦ ; � ��� � � � � ��

better resolution than mutracks

�

performance tested with in-situlight sources

�

Physical Review D, 67, 012003(2003)

Neutrino Astronomy at the South Pole – p.23/30

Cascades in AMANDA-II

10-2

10-1

1

10

10 2

4 4.5 5 5.5 6 6.5log10(Ereco/GeV)

even

ts /

197

d / 0

.2

experiment

background MC

E-2 signal MC

preliminary (2000 data) �

specific filter applied�

spherical topology�

energy cut� �}¨ search

�o p5© )� s� � t �wv �t x O �t x �t y �z t y

� � ��� : D8 ; < ��� / s� �t � s

�t x #%$ & O �t x �t y �z t y

� 2 {$ & < � p <� � |}$ &

Neutrino Astronomy at the South Pole – p.24/30

UHE Gm in AMANDA-B10

log10(Eν) (GeV)

E2 dN

/dE

ν (G

eV c

m-2

s-1sr

-1)

10-7

10-6

10-5

4 5 6 7 8 9 10

Flys Eye

ν

AMANDA

Baikal νe

AMANDA−B10 UHE

µν

νAMANDA

MACRO

e

µ

� D¡E with

� @ � � y u $ &from diffuse

sources�

concentrated in the horizon�selection of very bright events

�systematics study accounts for�

ice properties modeling�

absolute detector sensitivity�

neutrino cross sections

�

analysis under way in AMANDA-IIalso

Neutrino Astronomy at the South Pole – p.25/30

G from Supernovæ

�

Astrop Phys, 16 (2002)‘, 345-359

�

counting rate excess (in 10s bin) fromD8 ª J «� ª $

�

noise from OM only (300/1100 Hz)�

subsample of OM over 97/98 isselected�

get stable counting rate with a movingaverage

�AMANDA-B10�

70% coverage of Galaxy�o ¬� ) �� 2 ev/y (90% CL)

�

AMANDA-II�

90% coverage of Galaxy

Neutrino Astronomy at the South Pole – p.26/30

Summary

� AMANDA-B10 data published

� AMANDA-II data under analysis

� from 2002 online-filter

� AMANDA-II higher sensitivity

� THE FUTURE: IceCube

� in 2004 start to build

� 4800 OM (60 / string)

� string spacing 125 m

� digital transmission

� 1 km

2

instrumented volume

� IceTop surface arrayNeutrino Astronomy at the South Pole – p.27/30

Simulated UHE Event

Neutrino Astronomy at the South Pole – p.28/30

Experimental G­m event

Neutrino Astronomy at the South Pole – p.29/30

This is the END

Neutrino Astronomy at the South Pole – p.30/30