The ANTARES Neutrino Telescope Mieke Bouwhuis 27032006 Broadband

The ANTARES Neutrino Telescope Mieke Bouwhuis 27/03/2006

Broadband light source 1’ radio 1’ 1’ 1’ 10 -8 e. V optical 10 e. V x rays 104 e. V gamma rays 1012 e. V The pulsar in the Crab nebula

The observed radiation g e- eg Synchrotron radiation Inverse Compton scattering But: for some sources no synchrotron radiation is seen…

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

e, g, p and n from cosmic accelerators

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

Indirect neutrino detection median scattering angle (degrees) Neutrino interaction (ne, nm, nt): Scattering angle neutrino energy (Ge. V)

Neutrino cross section (cm 2) Mean free path: ~108 m at 1 Te. V neutrino energy (Ge. V) Very large volume needed

The ANTARES neutrino telescope Mediterranean Sea, near Toulon

Detection volume and medium § sea + earth = large volume Instrumented volume Effective volume = 0. 02 km 3 = 0. 2 km 3 (at 10 Te. V) =1 km 3 (at 10 Pe. V) § water for production of Cherenkov light § water is transparent § depth of 2. 5 km for shielding against atmospheric background

Detection principle c(tj - t 0) = lj + dj tan(qc) water properties dx = 20 cm dt = 1 ns dq = 0. 2°

Signals in the detector

Signals in the detector 100 k. Hz n crosses the detector in 2 ms

Different types of background proton atmospheric m atmospheric n Earth sea atmosphere proton cosmic n random background 100, 000 hits/s per phototube atmospheric m ~300/s atmospheric n ~10 -3/s

ANTARES data processing system • • • m all raw data 10 Gb/s finds all correlated data real time data reduction by factor 104 high efficiency (50%) high purity (90%) low threshold: En > 200 Ge. V finds cosmic neutrinos filter PC 1 Mb/s shore station physics data analysis

Angular resolution

February 14, 2006

March 2, 2006

Line 1: data taking Physics data taking LED beacon calibration

LED beacon for time calibration Line 1 MILOM ~70 m

Event Display – LED beacon

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

Event Display Physics event 17267 in run 21241 Physics event found by filter: 4 ms space-time correlated hits “snapshot” hit : hits used by the fit

Event Display Physics event 17267 in run 21241 zenith angle q = 179°

Event Display zenith angle q = 146°

Event Display zenith angle q = 80° Upgoing!

Zenith angle distribution 1394 events after 14 hours of data taking

Gamma-ray bursts (GRB) § short and intense flashes of Me. V 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 GRB warning systems GRB features Specific ANTARES features • All-data-to-shore concept filter PC GRB duration (s) Combine into the “GRB method” • Data processing farm • Software filters

Data taking after a GRB alert

Delays and buffering

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

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