First data of ANTARES neutrino telescope Francisco Salesa Greus IFIC (CSIC–Universitat de València, Spain) On behalf of the ANTARES collaboration The 3rd International Workshop on THE HIGHEST ENERGY COSMIC RAYS AND THEIR SOURCES May , INR-Moscow, Russia

Francisco Salesa2 Cosmic Ray spectrum SNR originGalactic origin (several theories) GZK cut-off: end of the cosmic ray spectrum?? AGN, top- down models?? Extra- galactic origin 1 particle per m 2 per second. 1 particle per m 2 per year. 1 particle per km 2 per year.  Cosmic Rays bombard us from anywhere beyond our atmosphere, with a very wide energy spectrum.

Francisco Salesa3 e-e- Low energy emission (X-ray) : Synchrotron emission of e - in jet  High energy emission (  -ray): - inverse-compton (electronic)? e-e-  ±±   ±   e  e ± If hadronic origin  high energy neutrinos  p     0 decay (hadronic) ? Neutrino connection High energy Cosmic Ray flux can constrain neutrino fluxes (Waxman-Bachall limit).

Francisco Salesa4 Physic topics Galactic Centre SNR Binary systems Micro- quasars AGN GRB  Neutrino Astrophysics  Dark matter: annihilation of neutralinos in massive objects (Sun, Galactic Centre,…)  Neutrino oscillations: atmospheric neutrino angular distribution.  Monopoles, top-down models, etc.  Other scientific topics: Biology, Oceanography, etc. Extragalactic sourcesGalactic sources

Francisco Salesa5 Detection principle  HE neutrino from extraterrestrial sources interacts in a CC reaction with the surrounding media.   A muon is produced which induces Cherenkov light emission.  Light Cherenkov is recorded by an array of PMTs. Cosmic accelerator   X reach the detector, not deflected  absorbed by matter and EBL p deflected by magnetic fields, GZK effect Earth CMB  Around 100 photons are emitted in 1 cm of flight path for “blue-UV” wavelength, where absorption in water and PMT efficiency are maximal. 1.2 TeV muon traversing the detector

Francisco Salesa6 Physical background  Two muon backgrounds: cos   (cm -2 s -1 sr -1 ) p p   Muons induced by atmospheric neutrinos. Background rejection on the basis of energy spectrum.  Atmospheric muons. Flux reduced due to detector depth. Background exclusion selecting only up-going events. The atmospheric  flux is 6 orders of magnitude higher than the flux induced by atm.

Francisco Salesa7 ANTARES collaboration 21 Institutions from 6 European countries Submarine cable  ANTARES detector located 40 km off Toulon coast (42º50’N 6º10’E) at 2500 metres depth.  A submarine cable links with the shore station placed at La Seyne sur Mer.

Francisco Salesa8 The ANTARES detector Horizontal layout m 100 m 350 m 12 lines 3x25 PMT/line Junction box Buoy Interlink cable Storey 40 km electro- optical cable to shore 12 lines 25 storey/line 3 PMT/storey 900 PMTs in total Anchor (BSS) Submersible

Francisco Salesa9 The ANTARES devices The ANTARES 10’’ PMT is housed in the Optical Module. A glass sphere protects it from high pressures. A μ-metal cage shields against the Earth magnetic field. The Hydrophone (Rx) for positioning. The Storey The Local Control Module houses, in a titanium frame, the electronic cards devised for the readout of the three OMs. The LED Beacon for time calibration purposes.

Francisco Salesa10 The ANTARES devices  A 40 km electro-optical cable links the shore station and the detector.  With 58 mm diameter, it is made up of 48 monomode pure silica fibre optics.  It provides the power and clock & commands signal to the junction box.  Junction box made up of titanium, splits the clock and commands signals to the BSS of each line.  The BSS anchors the line and controls the power and data transmission. It also contains some instruments as a pressure sensor or RxTx hydrophone. Junction box BSS

Francisco Salesa11 Time calibration  An internal LED monitors the transit time of the PMT.  The Optical beacons are external light sources for timing calibration  60 m 300 m The Laser beacon emits at 532 nm and is placed at the anchor of the MILOM. The LED beacon, emits blue light (472 nm) from 36 pulsed LEDs. Four beacons are placed along each line.  60 m 300 m  All the OMs are illuminated by OB. The time off-sets measured in the laboratory can be checked in-situ.

Francisco Salesa12 Positioning Autonomous Pyramid BSS Electro-optical cable to shore  The positioning system consists of an acoustic system, compasses and tiltmeters.  The acoustic system uses sound signals in the kHz range.  The tiltmeters provide the pitch and roll. The compasses, the magnetic field and heading. Fixed RxTx (transponder hydrophones) located in each BSS. In addition, 3 autonomous transponder pyramids are also fixed at the sea bed and located around the detector strings. Roll The Positioning System provides 10 cm accuracy for each OM.  Five Rx (receiving hydrophones) distributed in each line.  One tiltmeter-compass card per storey. Pitch

Francisco Salesa13 Detector performance  Effective area  Angular resolution   Earth opacity effect.  Below 10 TeV is dominated by the kinematic angle  .  Over 10 TeV dominated by reconstruction (calibration, electronics, etc.) kinematics reconstruction  rec, true  rec,  true  Effective area means the area of 100% efficient flat surface.  Depends on the incident neutrino flux.  Muon effective area is the relevant quantity to compare between experiments.  The maximum area is reached at TeV.  At high energies the Earth becomes opaque to neutrinos.

Francisco Salesa14 Point-like source candidates  ANTARES will observe 3π sr (galactic centre visible 67% of the time).  Complementary to AMANDA/IceCube at the South Pole (0.6π sr overlap).  HESS observations of RX J SNR spectrum show a presumably hadronic scenario, thus neutrino emission is expected (Nature 432 (2004) 75). TeV sources candidates. Galactic centre SNR RX J Vela pulsar

Francisco Salesa15 Source detection  Diffuse flux detection.  Point-like source detection.  Experimental limits for different experiments assuming E -2 spectrum.  Comparison between experiments for point-like sources detection.

Francisco Salesa16 Collaboration milestones & schedule  November 1999 & summer 2000: prototype lines  October 2001: Electro-optical cable deployment.  December 2002: Junction box (JB) connection.  December 2002: PSL (Prototype Sector Line) deployment.  February 2003: MIL (Mini Instrumentation Line).  March 2003: MIL & PSL connection to JB.  May and July 2003: MIL & PSL recovering.  Line 2 deployment foreseen by July  Lines 3 and 4 before the end of this year.  The whole detector will by finished by end  Science operation from FUTURE  March 2005: Line0 (test of mechanics) & MILOM (Mini Instrumentation Line with Optical Modules) deployment.  April 2005: MILOM connection.  May 2005: Line0 recovering.  February 2006: Line1 deployment.  March 2006: Line1 connection (Data analysis of Line 1 in progress).  : R&D and site evaluation period. FINAL DESIGN PROTOTYPES R&D

Francisco Salesa17 Site evaluation results blue (470 nm)UV (370 nm) abs 60 ± 8 m26 ± 2 m sct(eff) 265 ± 30 m120 ± 4 m   Water properties.  Biofouling.  Optical background. measured with pulsed LEDs Continuous component due to 40 K decay (salt) and bacteria colonies. Burst (20% over baseline) due to bioluminiscense abyssal creatures. At 90º a global loss of ~ 1.5% is expected in one year with a saturation tendency.

Francisco Salesa18 MILOM line  Instrumentation line + OMs: MILOM sketch  4 OMs.  2 LED Beacons.  1 Laser beacon.  1Rx hydrophone.  1RxTx transponder.  Successfully test of DAQ and electronics.  MILOM is still operating.  Sound velocimeter.  Seismometer.  Acoustic Doppler Current Profiler.  Conductivity Temperature probe.  3 Storeys.

Francisco Salesa19 Results from MILOM  Site properties: Example of data taking rate Baseline Bursts Baseline evolution with time Water current velocity evolution with time Heading of the three MILOM storeys Currents < 20 cm/s ~5 cm/s on average Correlation with currents has been noticed ~120 kHz Seasonal variations ~60 kHz summer autumn

Francisco Salesa20 Results from MILOM  Spatial Calibration: WF signal example.  Charge Calibration: Distance from autonomous line (RxTx) to MILOM RxTx, evolution with time. 175 m 96 m Evolution with time of the normalized charge.

Francisco Salesa21 Results from MILOM Internal LED  t evolution with time MILOM LED beacon Storey  Time Calibration: OM signal – beacon PMT time difference for each OM. The rate measured of these coincidences is ~13 Hz which is in agreement with the estimations. 40 K coincidences between OMs.

Francisco Salesa22 Line 1 deployment Line anchor Buoy OM LED beacon 25 storeys + 1 BSS RxTx

Francisco Salesa23 Line 1 deployment February 2006 March 2006

Francisco Salesa24 First muons reconstructed with Line 1  Triggered hits  Hits used in fit  Snapshot hits t [ns] z [m] + Result of Fit Antares preliminary  /   = 101 o  P(  2,ndf) = 0.88  /   = 172 o  P(  2,ndf) = 0.94 Antares preliminary  /   = 72 o  P(  2,ndf) = 0.37 Antares preliminary  Run / Event  Zenith angle  Fit probability

Francisco Salesa25 Atmospheric Muon Bundles MontecarloReconstruction  t [ns] Number of events [arbitrary units] Time residuals  = 7.8 ns Antares preliminary Number of events [arbitrary units] Antares preliminary P(  2,ndf)  t [ns] Number of events [arbitrary units] P(  2,ndf) Antares preliminary Time residuals  = 7.8 ns

Francisco Salesa26 Line 1 calibration MILOM LED Optical Beacon Line 1 ~70 m ~150 m  = 0.7 ns  = 2.6 ns  t [ns] Number of events [arbitrary units]

Francisco Salesa27 Future: KM3NeT  A km 3 (or larger) is the desirable volume for a neutrino telescope.  The KM3NeT Design Study has been approved by the European Union.  The three Mediterranean experiments collaborate in this study: ANTARES+NEMO+NESTOR.  Complementary to IceCube at the South Pole in order to cover the whole sky.  Technical Design Report early 2009.

Francisco Salesa28 Conclusions  The deployment of Line 1 and the on-going data taking is a great success.  Currently ANTARES is operating with the MILOM and Line 1 simultaneously.  2nd line deployment this summer, the whole detector will by finished by end  Atmospheric muons have been reconstructed. Presently working on angular distributions.  ANTARES will cover the South sky with an expected angular accuracy of 0.3º thanks to the optical properties of water and the good detector performances (electronics, calibration, etc).