Post on 30-Jan-2016
description
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IceCube: Multiwavelength Approach to Transient Neutrino Point Source Candidates
TeV Particle Astrophysics II 28-31 August 2006. Madison, WI
Elisa Resconi, for the IceCube coll. (Max-Planck-Institute for Nuclear Physics, Heidelberg)
http://icecube.wisc.edu
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IceCube event IceCube eventElisa Resconi
1. Construction of the Neutrino Sample
l
106 : 1
3
Cosmic ray showers in the Earth’s atmosphere:- , K decay
E-3.7
20% uncertainty
“diffuse” flux: CR interaction with interstellar gas.
“point-like”:galactic sources
E-2 ?
“diffuse” flux: p decay from p interaction with 2.7oK cosmic radiation
“point-like”:extra-galactic sources
E-2 ?
2. Extraction of Astronomical Information
atmgalacticextra- galactic
TeV-Blazar discussed here
See also at this conference: “Implications of neutrino flux limits” J. Becker for IceCube, talk “Search for a Diffuse Flux of TeV to PeV Muon Neutrinos with AMANDA-II” J. Hodges for IceCube, poster
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AMANDA-II preliminary: 2000-2004 (1001 live days),
4282from northern hemisphere
No significant excess found
galacticextra-galacticpoint-like sources
Elisa Resconi
= 00-04On-Source
Off-Source
Blind analysis strategy
Ref. M. Ackermann, “The multimessenger approach ..”, Barcelona, 07.06
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2000 2001 2002 2003
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Nr of
Time
datm(t)/dt = 1 / year 3o sky-bin
1 / day sky-bin ~ 310 -3
How can we discriminate these events ?
What can we learn from photonphoton observations?
Synthetic light curvePhoton Rate (counts/sec)
Multi-wavelength approach: photon light curves used for the improvement in identifypossible neutrinos emitted by astronomical sources
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1. The photon-neutrino link
2. Access to photon data
3. Analysis of photon data
3. Transient Point Sources
Selection of neutrino “proxy” waveband
Availability / calibration / dead-time correction …..
WHAT IS A FLARE ?
Elisa Resconi
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e,
e, γ synchr
γ synchr.
pγ γ synchr.
3.1 The photon – neutrino link: HBL (LBL)
P.Giommi et al.,A&A 445, 843-855 (2006)
γX
proton (highly magnetized environment) electron
Synchrotron proton blazar model (ref. A. Mücke et al, Astroparticle Phy, 18 (2003) 593-613)
Elisa Resconi
,
γ γ synchr
casc. (e±) γ synchr
casc. (e±) γ synchr
HBL
LBL
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γ- ray bandX- ray band
Interpretation primary electron AND secondary electron (casc.)
Data huge amount of data, monitor + high sensitivity
Strategy
Elisa Resconi
only p, if only synchrotron (no )
sporadic, no monitor,difficult to combine
collect all the data available,improve definition of “flare”
Light curve interpretationdefine “flares”define periods of high activity
HBL emission emissionX- AND γ-rayX- AND γ-ray
CORRELATION
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3.3 Photon data: WHAT IS A FLARE ?
Light Curve Interpretation:
characteristic flux level(s)
impulsive events (flares)
statistical studies on the timescales of variability
correlated activities across wavebands
periods of HE neutrino emission:
Construction of an hypothesis test
Maximum Likelihood Blocks applied to X- and -ray light curves
[E. Resconi, L. Costamante, D. Franco, E. Flaccomio, A. Gross, icecube/200608002]
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X-ray: an example All-Sky-Monitor (RXTE), Mkn 421All-Sky-Monitor, RXTE, 10 years X-ray monitor zoom Mkn 421
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All-Sky-Monitor, Maximum-Likelihood-Blocks zoom Mkn 421
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All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421
Rchar
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Characteristic level (band)Depends on: source + detector
Elevated levels or flares : ~ 15 %
+ 3
All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421
Rchar
Hypothesis test: need to be blind! 1. sample determined a priori 2. Time periods selected a priori 3. in the time periods / atmospheric expected
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TeV -ray: preliminary
The light curves are very sporadic
Compilation of historical light curves: under construction
Mkn 421, Whipple public data, Maximum Likelihood Blocks
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Multi-wavelength: X- vs -ray
“Orphan” region
“Anti-orphan” region
Correlated corridor
-ra
y flu
x
X-ray flux, PCA (MLB blocks)
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Future: … transition to a ‘multi-messengers’ approach
Elisa Resconi
- IceCube as a ( half ) – All-Sky-Monitor in neutrino:
- Filed of view: northern sky - High duty cycle
- Idea: use neutrinos in order to trigger gamma-ray telescopes(see E. Bernardini, “The multimessenger approach..” Barcelona, 07.06)
- Critical points under discussion:- selection of the sources: the phenomenology is limited- statistical interpretation of possible coincidences: -ray flare rate, catalogue … - blindness of the data:
minimal impact with off-line analysis
- Status: TEST run between AMANDA and Magic of 3 months approved.
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Summary
Looking in the right direction and in the right moment is a good idea!
From existing models: selection of proxy wavebands (HBL discussed)
Photon light curves under compilation
Photon light curve analysis with a global method (MLB)
Selection of periods of possible neutrino emission: global & non arbitrary
Next: test on the data
Elisa Resconi