Post on 19-Jan-2016
description
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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,
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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)
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
11
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
14
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
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
15
Latest deployments: line 0
A 23 storey line for testing electro-optical transmissionDeployed in march 2005
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
16
Mini instrumented line + 4 PMTs (MilOM)
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
17
Line connections 12-14 April, 2005
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
18
First test of in-situ time calibration system
OM ~ 0.7/2 ns well within spec.The expected angular resolution
should be achieved
Paris - June 16, 2005 A. Kouchner - High Energy Phenomena in the Galactic Center
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