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Search for neutrinos from gamma-ray bursts
with the ANTARES telescope
D. Dornic for the ANTARES Collaboration
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.
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)
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
D. Dornic – Rencontres de Moriond 2009
Triggered search method
Special DAQ strategy
ANTARES is a client of
the GCN
http://gcn.gsfc.nasa.gov/
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
+
D. Dornic – Rencontres de Moriond 2009
Triggered search methodResponse time to satellite triggers
October 2006 – December 2008
Response time (s)
Num
ber
of s
atel
lite
trig
gers
Fermi
Swift (2008 only)
D. Dornic – Rencontres de Moriond 2009
num
ber
of s
atel
lite
trig
gers
satellite triggers
satellite triggered data taking
date
Triggered search method
Blinded data
ANTARES GRB data taking: oct 06 – jan09
24 alerts from INTEGRAL244 alerts from Swift56 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
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)
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
D. Dornic – Rencontres de Moriond 2009
Rolling search methodSearch for “special” neutrino events on-line
Advantage: Large sky coverage
~100 % efficientNo 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
D. Dornic – Rencontres de Moriond 2009
Rolling search methodMultiplet of neutrino events (burst)
Cuts are tuned to give around 1 or 2 alerts per month
Single neutrino event with HE
212 22 atmatm RtR
11 1500 yrR atm
ΔΩ = 2° x 2°
Δt = 10 min
12 01.0 yrR atm
2 events coincidence rate: Application to ANTARES:
Above ~20 à 50 TeV, the background rate begins to be
negligible
D. Dornic – Rencontres de Moriond 2009
sin(θ)
Rolling search method
On-line reconstruction for the 10 lines detector
Elevation
Data : 307MC : 271MC : 7
Angular resolution
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 receptionLimit: difficult association with a source in the galactic plane
TAROT La Silla
D. Dornic – Rencontres de Moriond 2009
Rolling search method
Telescope TAROTν
Neutrino telescope
Trigger: multiple / HE single Reconstruction “on-line” (<10ms)Alert message
Real time
Principle
Observation strategy:Real time (T0) 6 images of 3 minutes
T0+1 day, +3 days, +9 days and +27 days
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
D. Dornic – Rencontres de Moriond 2009
Summary and perspectives
Special data without filtering for ~324 GRB alertsAnalysis 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