The ANTARES Neutrino Telescope Mieke Bouwhuis 27/03/2006

Broadband light source 1’ radio eV optical 10 eVx rays 10 4 eV gamma rays10 12 eV The pulsar in the Crab nebula

The observed radiation e-e-   e-e- Synchrotron radiationInverse Compton scattering But: for some sources no synchrotron radiation is seen…

All particle cosmic ray spectrum energy (eV) relative particle flux (logarithmic units) No point sources found yet

e, , p and from cosmic accelerators

Neutrinos from high-energy sources  Neutral  point back  Weak interaction  no absorption Active Galactic Nucleus (AGN) Supernova Remnant (SNR) Gamma-ray Burst (GRB) Pulsar Microquasar

Indirect neutrino detection Neutrino interaction ( e, ,  ): median scattering angle (degrees) neutrino energy (GeV) Scattering angle

Neutrino cross section neutrino energy (GeV) cross section (cm 2 ) Mean free path: ~10 8 m at 1 TeV Very large volume needed

The ANTARES neutrino telescope Mediterranean Sea, near Toulon

Detection volume and medium  sea + earth = large volume Instrumented volume= 0.02 km 3 Effective volume = 0.2 km 3 (at 10 TeV) = 1 km 3 (at 10 PeV)  water for production of Cherenkov light  water is transparent  depth of 2.5 km for shielding against atmospheric background

c(t j - t 0 ) = l j + d j tan(  c )  = 0.2°  x = 20 cm  t = 1 ns Detection principle water properties

Signals in the detector

crosses the detector in 2  s 100 kHz

Different types of background atmosphere sea Earth proton cosmic atmospheric atmospheric  random background100,000 hits/s per phototube atmospheric  ~300/s atmospheric ~10 -3 /s

ANTARES data processing system filter PC physics data all raw data 10 Gb/s 1 Mb/s analysis  shore station finds all correlated data real time data reduction by factor 10 4 high efficiency (50%) high purity (90%) low threshold: E > 200 GeV finds cosmic neutrinos

Angular resolution

February 14, 2006

March 2, 2006

Line 1: data taking LED beacon calibration Physics data taking

LED beacon for time calibration MILOM Line 1 ~70 m

Event Display – LED beacon

Muon trigger rate rate (Hz) number of correlated hits real data Monte Carlo Physics event found by filter: space-time correlated hits “snapshot” hit 4  s

Event Display Physics event found by filter: space-time correlated hits “snapshot” hit 4  s : hits used by the fit Physics event in run 21241

Event Display zenith angle  = 179° Physics event in run 21241

Event Display zenith angle  = 146°

Event Display zenith angle  = 80° Upgoing!

Zenith angle distribution 1394 events after 14 hours of data taking

Gamma-ray bursts (GRB)  short and intense flashes of MeV gamma rays  happen unexpectedly, and take place at random locations in the sky  detected by satellites  most information from the observation of the ‘afterglow’  mechanism:

GRB warning systems

Detection of neutrinos from GRBs filter PC All-data-to-shore concept Data processing farm Software filters Specific ANTARES featuresGRB warning systemsGRB features GRB duration (s) Combine into the “GRB method”

Data taking after a GRB alert

Delays and buffering

Gain in sensitivity for GRBs neutrino energy (GeV) ratio of effective volumes standard GRB method

Conclusions  Composition of jets → e versus p  Origin of UHE cosmic rays  Line 1 operational, 12 lines end of 2007  Measured time resolution of ~1 ns  Expected angular resolution 0.2°  GRB method increases the sensitivity