Antoine Kouchner Université Paris 7 Laboratoire APC - CEA/Saclay for the ANTARES collaboration Neutrino Astronomy: a new look at the Galaxy Astronomy Neutrino

Antoine KouchnerUniversité Paris 7

Laboratoire APC - CEA/Saclay

for the ANTARES collaboration

Neutrino Astronomy: a new look at the Galaxy

Astronomy Neutrino Telescope with Abyss environmental RESearch

http://antares.in2p3.fr

International Conference of the 5th APC WorkshopHigh Energy Phenomena in the Galactic Center

Paris, 15th - 17th June 2005

Detection principlesThe case for the GC

ANTARES status

Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center

2

č

č

Time, position, amplitude of PMTpulses trajectory (~ < 0,5 °)

Detection of Cherenkov light emitted by muons with a

3D array of PMT

Requires a large dark transparent

detection medium

Muon neutrino detection principle

well suited for HE detection

Both range and cross-section

increase with energy

Large effective volume


3

Background constraints

10-7

cos

atmospheric muons

muons inducedfrom atmospheric

106

d

/d

cm

-2 s

-1 s

r-1

10-9

10-11

10-13

10-15

10-17

2400 m depthE > 1 TeV

Very intense atmospheric muon flux

Signal = upward muons

log (energy)

log

(d

N/d

E)

νμatm E-3,7

νμcosm E-2

Energy cut

p

AtmosphereSea

p,


4

Visible sky and detector latitude

South Pole visible sky

Mediterranean visible sky

The Galactic Center cannot beseen by AMANDA/IceCube

with upward muons

A Mediterranean detectorwill see the GC 2/3 of the time

3.5 sr covered

Visibility timefraction for Antares


5

The ANTARES collaboration

Cable

Assembly hall

Powerstation

Electro-opticalCable

Shore stationInstitut Michel Pacha

IFICValencia

IFREMER, BrestDAPNIA, SaclayIReS, Strasbourg MulhouseCPPM MarseilleIFREMER,ToulonCOM, MarseilleVillefranche

ITEPMoscow

NIKHEFGroningenAmsterdam

GenovaBari

CataniaRoma

Erlangen

LNS

PisaBologna


6

a storey

The 12 string Antares Telescope

• 25 storeys / line• 3 PMTs / storey• 900 PMTs

~70 m

350 m

100 m

14.5 m

Submarine links

JunctionBox

40 km to shore

Anchor/line socket2005-2007F. Montanet


7

• Eµ > 10 TeV ~ 0.2º

• E µ < 10 TeV µ kinematics dominated

Angular resolution

HE expected performances ()

Muon effective surface

AtN

tNAEff //

/incident

detected


8

Background associated to point sources

E>1TeV

Nb selected

atm.

per year (average)

In the GC

direction

2 300

1° 0.05 0.03

0.5° 0.01 0.007

After quality cuts, the remaining background is due to atmospheric neutrinos only

A. Heijboer ‘s thesis

Very low background for point-like sources !!

No energy cut


9

Inferring flux from observations

2 1e 0

for 1

Assume hadronic origin of the observed -rays from GC

p + p

ee ee

)(4)2/(

EdE

dFEE

dE

dFv Then d/dE2

At source !

2

EE 42)1( 2

2

EEm

mE 43

EEEE e

For E [E1, E2] 22

21

42

41

2E

E

E

EdE

dE

dFdE

dE

dF

L. Anchordoqui, Acta Phys.Polon. B36 (2005) 495

e:: =1:2:0 at source e:: =1:1:1 at Earth ! noscillatio


10

HESS observations - Energy spectrum

dF/dE = F0 E- m-2 s-1 GeV-1 with = 2.2 & F0 = 1.1×10-4

Aharonian et al., A&A 425, L13-L17 (2004)

Neutrinos from the GC

dF/dE = 4.8 ×10-5 E-2.2 m-2 s-1 GeV-1 (including oscillations)


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from the GC – Expected rates

ANTARES not large enough

Need at least 1 km3 detector !(~1 event /year)

Most of the signal aroundE ~10 TeV

~0.03 evt / year

2.10-2

3.10-2

10-2

Nb events with E>E

PRELIMINARY

2.10-3

3.10-3

10-3

neutrino

anti-neutrino

Nb events per bin


12

Extrapolated rates in a km3 detector

Energy dependenceof the effective surface

should be taken into account

The Mediterranean km3 detector layout

is not fixed

Realistic scaling factor 40


13

Rates in Antares and a km3 detector

E>1TeV

d0.5°

Not optimized

PRELIMINARY

ANTARES KM3

Signal events /year

Bkg events /year

Time for

detection

(4 CL)

Time for

detection

(4 CL)

GC

HESS 210-2

710-3

247 yr 6.2 yr

EGRET+EHECRCrocker et al (2005)

2 0.4 yr week

RX J1713.7-3946

Constantini et al (2005) 0.16

910-3

15 yr 0.4 yr

Halzen et al

(2002)0.95 1.8 yr 3 weeks

PSR B1509-

58

HESSMSH 15-52

0.11 1.110-2 22 yr 0.6 yr


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Increasing sensitivity for point sourcesM. Bouwhuis’ thesis

Use prior knowledge of the source directionfor both filtering and reconstruction

Method originally developed for GRB alerts

rela

tive

effic

ienc

y

neutrino energy (GeV)

Could be used onlinefor persistent sources

like the GC

Gain by a factor of ~2

- About 5 times more CPU needed

per source


15

Latest deployments: line 0

A 23 storey line for testing electro-optical transmissionDeployed in march 2005


16

Mini instrumented line + 4 PMTs (MilOM)


17

Line connections 12-14 April, 2005


18

First test of in-situ time calibration system

OM ~ 0.7/2 ns well within spec.The expected angular resolution

should be achieved


19

Conclusions

ANTARES is a first step towards the Mediterranean km3

• Electronics tested in situ in its latest version

• Calibration system operational

• The detector should be complete late 2007

• Could indicate surprise from the Galactic Center

Observation neutrino from GC likely with a Northern km3

• Requires a good angular resolution (muon neutrinos)

• The associated background is very low

• The detection of a few events is significant

• The absence of signal will constrain the emission models

Latest deployments

ANTARES will be the biggest NT with GC in its field of view

Documents

Antoine Kouchner Université Paris 7 Laboratoire APC - CEA/Saclay for the ANTARES collaboration Neutrino Astronomy: a new look at the Galaxy Astronomy Neutrino