Status and recent data of the ANTARES Neutrino Telescope

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Status and recent data of the ANTARES Neutrino
Telescope

• Thomas Eberl Erlangen Centre for Astroparticle
  Physics
• for the ANTARES collaboration
• TeV Particle Astrophysics workshopSLAC, July 2009

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The ANTARES Collaboration
23 institutes in 7 European countries
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The ANTARES Collaboration
23 institutes in 7 European countries
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The ANTARES Detector
2m
Cable
ANTARES2500m depth
12 lines with 25 storeys each total of 885
PMTs Completed 30-May-2008
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A Storey The Basic Detector Element
Optical Beacon (blue LEDs) for timing
calibration (4 per line)
Local Control Module (inside a titanium cylinder)
Optical Module 17 glass sphere 10 PMT Ham.
R7081-20 (14 stages)
Hydrophone RX (5 per line)
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High Energy Neutrino Detection Principle
3D PMT array
Cherenkov light from m
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Sea floor
Time position of hits
m
m
interaction
nm
m ( n) trajectory
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Background and Construction Progress
Precursorline
2 lines
Full Antares
1 line
5 lines
10 lines
Single PMT rate
Cable Fault
2005
2006
2007
2008
2009
40K decays and bioluminescent bacteria (rate
60 kHz)
bursts from macroorganisms
Runs with high rate or large burst fraction
fail quality cuts High activity during spring
2006, 2009 correlation with particularly
cold winters?
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Muons
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Detector footprint in muons

• Detector as seen by atmospheric muons
  projection of fitted track position at time of
  the first triggering hit

first 2 weeks of datatrack seen onminimum 3
linestriggered hit high amplitude pulse
or storey coincidence
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(multi-) Muon Event
Example of a reconstructed down-going muon,
detected in all 12 detector lines
height
time
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Depth Intensity Relation
Reconstructed tracks as a function of zenith
angle ? Use track length in water (slant depth)
30 days of livetimeAtmospheric muonswith Egt20
GeV Systematic uncertainties shownEnvironment
al and alignment parametersTrack selection
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EM showers in ANTARES
MMeasured Rate of muonsp producing N showers
5.6 days of data with 5-line detector
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Neutrinos
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Neutrino Candidate
Example of areconstructed up-going muon(i.e. a
neutrino candidate) detected in 6/12 detector
lines
z (height)
time
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Data 2007/2008 and Comparison to MC
5 lines (2007)
1.9 107 triggered events Total 245 days 79
of calendar Selected 168d 69 of total
10 (9) lines (2008)
6.5 107 triggered events Total 242 days 77
of calendar Selected 173d 71 of total
Neutrino Candidates (after quality
cuts) Data 1062 events MC 916 atmospheric
neutrinos 40 atmospheric muons
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ANTARES Neutrino Sky Map
5-Line Data (2007) Require hits in at least 2
lines (to determine right ascension) Additional
quality cuts Live time of 140 days 94 Neutrinos
selected
(Equatorial coordinates)
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Point Source Search
List of 25 sources for search
Calculate neutrino flux limit
3C 279
GC
Cent A
No significant excess in directionof sources
observed
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ANTARES Neutrino Sky Map
Data of 2007 and 2008 750 multi-line
Neutrinos selected Data still blinded,
positions are scrambled!
(Galactic coordinates)
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Dark Matter Searches
5-line data, 68.4 days (168 days 0.51 Sun
under horizon 0.8 trigger
eff.) No excess observed Long term investigation
necessary (3 years with 12 lines)
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Multi Messenger Approaches
Gamma Ray Bursts (GRBs)

• GCN alerts trigger the recording of all low
  level triggers
• 90 of GCN alerts are handled by ANTARES ? 9
  TB of data

Fast Responding Robotic Optical Telescopes (TAROT)

• ANTARES alert two events with ?O lt 3x3 in
  ?t lt 15 min rate(atm) 0.05 yr-1
• TAROT two 25 cm telescopes at Calern
  (France) and La Silla (Chile)
• FOV 1.86 x 1.86
• 10s repositioning after alert reception
• sending alerts since May 09

Gravitational Waves (Ligo/Geo600/Virgo)

• letter of intent prepared

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The AMADEUS System of ANTARES
Goal Feasibility study of acoustic detection
techniques
?
hadronic cascade
1km
10m
Expect bipolar pressure pulse

• Taking data since 5-Dec-2007
• Completely installed since 30-May-2008

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Direction Reconstruction of Acoustic Sources
Most probabledirection of source
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Marine Sound Sources
S
N
W
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Summary and Outlook

• ANTARES was completed (12 detection lines) in
  May 2008
• Muons under control e.g. Depth intensity
  relation and
  EM showers measured
• More than 1000 upgoing events (neutrino
  candidates) have been reconstructed (Jan 09)
• First results from analysis with 5-line
  configuration (search for point-like sources).
• Multi messenger approaches pursued
• ANTARES used as multidisciplinary platform(e.g.
  acoustic neutrino detection)

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Backup Slides
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Expected Performance (full detector)
Neutrino effective area
Angular resolution
NdetAeff Time Flux

• For E? lt 10 TeV, the angular resolution is
  dominated by the ?-? angle.
• For E? gt 10 TeV, the resolution is limited by
  track reconstruction errors.

• For E?lt10 PeV, Aeff grows with energy due to the
  increase of the interaction cross section and the
  muon range.
• For E?gt10 PeV the Earth becomes opaque to
  neutrinos.

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Acoustic detection of (U)HE ?s
energy deposition in (hadronic) cascade ?
bipolar pressure pulse in disc shape

• Acoustic detector
• 3D array of hydrophones
• very long attenuation lengths (of order 1km)
• medium water, ice and salt

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ANTARES angular resolution
MC - simulation
Electronics simulation light absorption
scattering light background ( 40K
bioluminescence 60 kHz )
Eµ gt10 TeV
kinematics
reconstruction
m
Angular resolution lt 0.3
n
WATER on ANTARES site
labs 26/60 m _at_ 370/470 nm
leff (scattering) 100/300 m _at_ 370/470 nm
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Status Detector complete since May 30, 2008
12 lines with 885 PMTs and 1 instrumentation line
IL07for the control of environmental parameters
(e.g. sea current, temperature, ...)
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Duration of lines in sea up to 3.5 y

• Junction Box operational in deep sea since 6.5
  years
• Line 1 works for more than 3 years

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Cable Failure and Repair

• Standard 40 km deep-sea telecommunications cable
  used to connect shore station and junction box.
• Cable failed in July 08, connection to detector
  was lost.
• Investigations showed that sea water had
  penetrated 100m into the cable.
• Successful and standard repairing procedure by
  France Telecom Ship 8 days ago!

ANTARES is back onlinestatus of detector is
unchanged.
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Optical background rates

• Dominated by 2 effects
• 1. b decay of 40K
• 2. bioluminescent organismse.g.

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Calibration with Potassium-40
Under investigation PMT ageing?Gain drop
compensated by threshold tuning
on average 35 photons
40K decay(ß or EC)
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Acoustic positioning

• Determination of line shapeand of module
  coordinatesevery 2 minutes by
• Acoustic triangulation
• Compass data of storeysheadings and tilts

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Alignment with acoustic positioning

• Hydrophone positions relative to line anchor

• Crucial to reach track resolution lt 1 degree
• Lines are floating with the deep sea water
  current !
• Typical water speed a few cm/s

Necessary precision is reached? positioning is
under control
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Detector status after cable repair
ONLINE CONTROL 12 of channels w/ low or w/o
count ratemostly power or HV failure 2
sectors ( 5 floors, red) are unreachable
Floor nb
Line nb
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Deployment
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Connection
Victor (ROV)
Nautile (manned)
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Pictures from the seabed
Detector layout
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Point-like searches with 5 lines

• No excess found, neither in the search within the
  list of candidates nor in the all-sky search
• Significance of fluctuations
• 1.6? (list of sources)
• 1.0 ? (all sky)
• First limits have been set and are competitive
  with previous multi-year experiments (with only
  less than half of the detector and 140 of live
  time!)
• Blinding policy has been followed.
• Paper with these results almost ready for
  submission.

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List of 25 sources
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Region of sky observable by Neutrino Telescopes
ANTARES (43 North)
AMANDA/IceCube (South Pole)
Mkn 421
Mkn 501
Mkn 501
RX J1713.7-39
GX339-4
Galactic Centre
V. Bertin - CPPM - ARENA'08 _at_ Roma
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gt100 GeV gamma skymap
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Time calibration with LED beacons

• Four LED beacons/line (with 36 blue LEDs each)
  allow to illuminate the neighbouring OMs
• Good technical performance (45/47 are working)
• Additional output water optical parameter
  measurement

Electronics contribution less than 0.5 ns
Lines 1-10

• Residual time offset grows with distance (early
  photon walk effect) according to a straight ?
  offsets measured in the dark room before
  deployment can be corrected
• Checked with independent K40 tests

Only 15 are larger than 1 ns
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Positioning

• Acoustic system
• One emitter-receiver at the bottom of each line
• Five receivers along each line
• Four autonomous transponders on pyramidal basis
• Additional devices provide independent sound
  velocity measurements

Measure every 2 min -Distance line bases to 5
storeys/line andtranspoders -Headings and tilts
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Positioning results
Comparison among storeys
Larger displacements for upper top floor
Comparison among lines
Coherent movement for all the lines of the
detector
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Time residuals for point source analysis
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Accumulated data
10 lines (2008)
65 106 µ triggers
19 106 µ triggers

• 5 lines (2007)

Cable repair
Total 245 days 79 of calendar Selected 168d
69 of total
Total 242 days 77 of calendar Selected 173d
71 of total
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Data-MC comparison for downgoing events (5-lines)

• No quality cuts applied
• Agreement within (substantial) theoretical MC
  uncertainty
• Main experimental errors stem from OM efficiency
  and acceptance and optical water properties (?
  abs ?scatt)