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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

1

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