1. Search for neutrinos from gamma-ray bursts with the ANTARES telescope D. Dornic for the ANTARES Collaboration

2. D. Dornic – Rencontres de Moriond 2009 Neutrinos from GRBs GRBs : powerful cosmic particle accelerators producing a highly variable flux of high energy gamma-rays. Under the assumption of hadronic acceleration in jets  a copious flux of neutrinos expected Among the possible astrophysical sources, GRBs offer one of the most promising perspectives for the detection of cosmic neutrinos thanks to an almost background free search.

3. D. Dornic – Rencontres de Moriond 2009 Neutrinos from GRBs  ~ 100  ~ 10 The Fireball model tells us how GRBs operate, but: - Which processes generate the energetic ultra-relativistic flows? - How is the shock-acceleration realized ? High energy neutrinos expected by photonuclear interactions of the observed gamma-rays with the protons accelerated by the internal shocks (typical energy above ~10 TeV)

4. D. Dornic – Rencontres de Moriond 2009 GRB search techniques Detection in conjunction with accurate timing and positional information provided by an external source Triggered search Rolling search Searching for multiplets of neutrino events from the same direction and within a short time window

5. D. Dornic – Rencontres de Moriond 2009 Triggered search method Special DAQ strategy ANTARES is a client of the GCN http://gcn.gsfc.nasa.gov/

6. D. Dornic – Rencontres de Moriond 2009 Triggered search method ANTARES SWIFT, INTEGRAL, Fermi alerts reception GRB data storage during 2 minutes without filtering Standard acquisition +

7. D. Dornic – Rencontres de Moriond 2009 Triggered search method Response time to satellite triggers October 2006 – December 2008 Response time (s) Number of satellite triggers Fermi Swift (2008 only)

8. D. Dornic – Rencontres de Moriond 2009 number of satellite triggers satellite triggers satellite triggered data taking date Triggered search method Blinded data ANTARES GRB data taking: oct 06 – jan09 24 alerts from INTEGRAL 244 alerts from Swift 56 Alerts from Fermi ANTARES data for 324 alerts 29 during line 1-2 period 120 during line 1-5 period 57 during line 1-10 period 118 during line 1-12 period

9. D. Dornic – Rencontres de Moriond 2009 Triggered search method Advantage: The nature and the location of the source is known Very low background rate Low energy threshold Disadvantages: Depend on external sources SWIFT (1.4 sr fov) → only ~1 / 9 GRB is detected no external trigger for choked GRBs)

10. D. Dornic – Rencontres de Moriond 2009 GRB search techniques Detection in conjunction with accurate timing and positional information provided by an external source Triggered search Rolling search Searching for multiplets of neutrino events from the same direction and within a short time window

11. D. Dornic – Rencontres de Moriond 2009 Rolling search method Search for “special” neutrino events on-line Advantage: Large sky coverage ~100 % efficient No assumption on the nature of the source Disadvantages: the nature of the source is unknown → need a follow-up program to confirm detection (nature, redshift…) → need a very fast analysis with a good angular resolution

12. D. Dornic – Rencontres de Moriond 2009 Rolling search method Multiplet of neutrino events (burst) Cuts are tuned to give around 1 or 2 alerts per month Single neutrino event with HE ΔΩ = 2° x 2° Δt = 10 min 2 events coincidence rate:Application to ANTARES: Above ~20 à 50 TeV, the background rate begins to be negligible

13. D. Dornic – Rencontres de Moriond 2009 sin(θ) Rolling search method On-line reconstruction for the 10 lines detector Elevation Data : 307 MC : 271 MC  : 7 Angular resolution

14. D. Dornic – Rencontres de Moriond 2009 Rolling search method Collaboration with the TAROT telescopes array TAROT: two 25 cm telescopes located at Calern (South France) and La Silla (Chile) - fov 1.86° x 1.86° - Magnitude V<17 (10s) V<19 (100s) - ~ 10s repositioning after the alert reception Limit: difficult association with a source in the galactic plane TAROT La Silla

15. D. Dornic – Rencontres de Moriond 2009 Rolling search method Telescope TAROT ν Neutrino telescope Trigger: multiple / HE single Reconstruction “on-line” (<10ms) Alert message Real time Principle Observation strategy: Real time (T 0 ) 6 images of 3 minutes T0+1 day, +3 days, +9 days and +27 days

16. D. Dornic – Rencontres de Moriond 2009 Rolling search method First alert Time: 2009-01-16 11:15:53.00 Zenith = 70.16 azimuth = 61.89 Representation

17. D. Dornic – Rencontres de Moriond 2009 Summary and perspectives Special data without filtering for ~324 GRB alerts Analysis is ready & unblinding requested Rolling search method By complementing neutrino telescopes with an optical follow-up, one gains significant sensitivity for transient sources. The system is operational with TAROT since one week. We are waiting for alerts. Interesting to extend technique to other wavelength (X-ray, radio). Triggered search method