1. CPPM: M. Ageron, I. Al Samarai, V. Bertin, J. Brunner, J. Busto, D. Dornic, S. Escoffier IRFU: B. Vallage LAM: S. Basa, B. Gendre, A. Mazure TAROT: M. Boer, A. Le Van Suu (OHP), A. Klotz (CESR)

2. Scientific motivations Detection of transient sources such as: - Gamma Ray Bursts - Core Collapse Sne - AGNs - Microquasars - …  Observed in many wavelengths (X, visible…)  Potential neutrino emitters  So far, only 1 detection of extrasolar neutrinos) Microquasar luminosity vs time

3. Scientific motivations One of the most interesting: GRBs: - Highly energetic gamma bursts (~10 51 ergs) - Observed at a rate <1 per day with gamma satellites - Other detections are triggered by a satellite alert (Optical telescopes, neutrino telescopes…) Failed GRBs: - Not visible in gamma but potentially neutrino emitters - How to trigger a detection for such objects?

4.  Rate of local GRBs << SN rate The GRBs/SNe Connection

5.  Rate of local GRBs << SN rate  Core Collapse SNe : jets with different velocities:  Highly relativistic  GRBs (  )  Mildly relativistic  « Failed GRBs » (few%) (hidden in gamma) The GRBs/SNe Connection

6. In « failed GRBs »: No gamma counterpart Still, protons are accelerated  p-p interaction  Mesons  Mesons decay into neutrinos Ando & Beacom (PRL 95,061103(2005)) Razzaques, Meszaros,waxman (PRL 93,181101(2004)) (PRL 94, 109903(2005)) Expected neutrino flux from a FGRB in ANTARES

7. In « failed GRBs »: No gamma counterpart Still, protons are accelerated  p-p interaction  Mesons  Mesons decay into neutrinos Antares threshold Ando & Beacom (PRL 95,061103(2005)) Razzaques, Meszaros,Waxman (PRL 93,181101(2004)) (PRL 94, 109903(2005)) Expected neutrino flux from a FGRB in ANTARES

8. For the Multiplet (>= 2 neutrinos) trigger:  Horizon at 10 Mpc When applying HE event conditions, For 1 HE neutrino:  Horizon at 1 Mpc For 1 SNe LE events  The Multiplet trigger can push the horizon of detection further than the HE event trigger does HE events

9. ANTARES: 900 PMTs - TAROT Sud (Chili) - FOV :2° x 2° - Fast repositioning (10s) - Good sensitivity (V<19)  Idea: Optical detection of transient sources triggered by ”special” neutrino events.  Main advantage: covers the full hemisphere

10. Keys of success: 1. High performance of the online reconstruction 2. Good event selection GCN alert Triggers: Multiplet of neutrinos Single HE neutrino  Alert On-line reconstruction Upward-going event ANTARES: 900 PMTs - TAROT Sud (Chili) - FOV :2° x 2° - Fast repositioning (10s) - Good sensitivity (V<19)

11. Median Angular resolution vs energy  Angular resolution as good as 0.5° for highest energetic events A very fast algorithm is needed  Reconstruction taking 10ms / event is implemented The better is the reconstruction angular resolution  the easier it is to find the source in the image analysis phase Reconstruction on at least 3 detector lines required to avoid mirror solutions

12.  Trigger: Doublet of neutrinos  A detection would be almost significant ΔΩ = 3° x 3° Δt = 15 min Background estimation:  High energy events Background: Dominated by atmospheric neutrinos Median Ang. Res.~ 0.75° E moy ~4 TeV After cuts on energy estimators: MC Seen on at least three detector lines The TaToO project Keys of success (2/2) Event selection

13.  High energy events Background: Dominated by atmospheric neutrinos Median Ang. Res.~ 0.75° E moy ~4 TeV After cuts on energy estimators: MC  Tuned actual cuts to send 1 to 2 alerts/ month to TAROT; mostly would be from HE trigger The TaToO project Keys of success (2/2) Event selection Number of hits used in track fit Total amplitude 2008 data

14. z t Example of HE neutrino Representation 2D (height/time) Representation 3D

15. GRB afterglow F ~ t -1.2 10 Minutes Core-collapse SNe Two promising source classes for this detection: TAROT observation strategy after alert reception: Real time (T 0 ) : 6 images of 3 minutes T0+1 day, +3 days, +9 days and +27 days  This detection strategy is appropriate to follow the main objects time profile and to allow a reasonable time for image analysis The Observation strategy

16. A standard image Subtraction result Still to be done: 1)Test the subtraction algorithm: some problems due to the very variable PSF (variable atmospheric conditions, image quality on the CCD edges) 2)Include the tool in an automatic system Example Increasing luminosity Decreasing luminosity Badly substracted Tuning a tool originally used for SNe identification

17.  TAToO is a promising detection tool of transient sources using neutrino telescopes as a trigger  This is the only method to detect satellites hidden sources as FGRBs  Several alerts sent already to Tarot  Image analysis tools are studied  In the future, this system is intended to be coupled with other detections (Rotse, Swift, ATA…)