CPPM : M. Ageron, I. Al Samarai, V. Bertin, J. Brunner, J. Busto, D. Dornic, S. Escoffier
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Transcript of CPPM : M. Ageron, I. Al Samarai, V. Bertin, J. Brunner, J. Busto, D. Dornic, S. Escoffier
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)
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 : SN1987A
Microquasar luminosity vs time
Scientific motivations
Some of the most interesting:
GRBs:- Highly energetic gamma bursts (~1051 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?
Rate of local GRBs << SN rate
The GRBs/SNe Connection
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
In « failed GRBs »:• No gamma counterpart• Still, protons are acceleratedp-p interaction MesonsMesons 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
In « failed GRBs »:• No gamma counterpart• Still, protons are acceleratedp-p interaction MesonsMesons 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
•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
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
Keys of success:1. High performance of the online reconstruction2. Good event selection
GCN alert
Triggers:Multiplet of neutrinosSingle 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)
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
Trigger: Doublet of neutrinos
A detection would be have 3 significance
1atm yrR 300
1
ΔΩ = 3° x 3°Δt = 15 min
1atm yrR 0.007
2
Background estimation: High energy eventsBackground: 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 projectKeys of success (2/2)
Event selection
High energy eventsBackground: 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 projectKeys of success (2/2)
Event selection
Number of hits used in track fit
Total amplitude
2008 data
2008 data
z
t
Example of HE neutrinoRepresentation 2D (height/time) Representation 3D
GR
B
aft
erg
low
F ~ t-1.2
10 Minutes
Core
-colla
pse
S
Ne
Two promising source classes for this detection:
TAROT observation strategy after alert reception:Real time (T0) : 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
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
Exam
ple
Increasing luminosityDecreasing luminosityBadly substracted
Tuning a tool originally used for SNe identification
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 detectors (Rotse, Swift, ATA…)