Ice Cube Multiwavelength Approach to Transient Neutrino Point
Ice. Cube: Multiwavelength Approach to Transient Neutrino Point Source Candidates Elisa Resconi, for the Ice. Cube coll. (Max-Planck-Institute for Nuclear Physics, Heidelberg) http: //icecube. wisc. edu Te. V Particle Astrophysics II 28 -31 August 2006. Madison, WI 1
1. Construction of the Neutrino Sample 106 : 1 l F (E, W) Ice. Cube event Elisa Resconi 2
2. Extraction of Astronomical Information F (E, W) = Fatm + Fgalactic + Fextra- galactic Cosmic ray showers in the Earth’s atmosphere: - , K decay E-3. 7 20% uncertainty “diffuse” flux: CR interaction with interstellar gas. “diffuse” flux: p decay from p interaction with 2. 7 o. K cosmic radiation “point-like”: galactic sources “point-like”: extra-galactic sources Te. V-Blazar E-2 ? discussed here E-2 ? See also at this conference: “Implications of neutrino flux limits” J. Becker for Ice. Cube, talk 3 “Search for a Diffuse Flux of Te. V to Pe. V Muon Neutrinos with AMANDA-II” J. Hodges for Ice. Cube, poster
Fgalactic(E, W), Fextra-galactic(E, W) point-like sources Ref. M. Ackermann, “The multimessenger approach. . ”, Barcelona, 07. 06 On-Source = 00 -04 Off-Source AMANDA-II preliminary: 2000 -2004 (1001 live days), 4282 from northern hemisphere No. Blind significant analysis excess strategy found Elisa Resconi 4
Multi-wavelength approach: photon light curves used for the improvement in identify possible neutrinos emitted by astronomical sources Synthetic light curve Photon Rate (counts/sec) Nr of d. Fatm(t)/dt = 1 / year 3 o sky-bin 1 / day sky-bin ~ 3 10 -3 1 2000 2001 How can we discriminate these events ? 2002 2003 Time What can we learn from 5 photon observations?
3. Transient Point Sources 1. The photon-neutrino link Selection of neutrino “proxy” waveband 2. Access to photon data Availability / calibration / dead-time correction …. . 3. Analysis of photon data WHAT IS A FLARE ? Elisa Resconi 6
3. 1 The photon – neutrino link: HBL (LBL) Synchrotron proton blazar model (ref. A. Mücke et al, Astroparticle Phy, 18 (2003) 593 -613) proton pγ (highly magnetized environment) , γ γ synchr e, γ synchr casc. (e±) γ synchr e, electron γ synchr. X γ γ synchr. casc. (e±) γ synchr LBL HBL P. Giommi et al. , A&A 445, 843 -855 (2006) Elisa Resconi 7
X- AND γ-ray HBL γ- ray band X- ray band Interpretation primary electron AND secondary electron (casc. ) Data huge amount of data, monitor + high sensitivity Strategy Light curve interpretation define “flares” define periods of high activity Elisa Resconi emission C O R R E L A T I O N only p, if only synchrotron (no ) sporadic, no monitor, difficult to combine collect all the data available, improve definition of “flare” 8
3. 3 Photon data: WHAT IS A FLARE ? Light Curve Interpretation: ü characteristic flux level(s) ü impulsive events (flares) ü statistical studies on the timescales of variability ü correlated activities across wavebands Ø periods of HE neutrino emission: ØConstruction 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] 9
X-ray: an example All-Sky-Monitor (RXTE), Mkn 421 All-Sky-Monitor, RXTE, 10 years X-ray monitor Elisa Resconi zoom Mkn 421 10
All-Sky-Monitor, Maximum-Likelihood-Blocks Elisa Resconi zoom Mkn 421 11
All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421 Rchar Elisa Resconi 12
Hypothesis test: need to be blind! 1. sample determined a priori 2. Time periods selected a priori 3. in the time periods / atmospheric expected All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421 Elevated levels or flares : ~ 15 % + 3 Rchar Characteristic level (band) Depends on: source + detector Elisa Resconi 13
Te. V -ray: preliminary Ø The light curves are very sporadic Ø Compilation of historical light curves: under construction Mkn 421, Whipple public data, Maximum Likelihood Blocks Elisa Resconi 14
-ray flux Multi-wavelength: X- vs -ray “Orphan” region Correlated corridor “Anti-orphan” region X-ray flux, PCA (MLB blocks) Elisa Resconi 15
Future: … transition to a ‘multi-messengers’ approach - Ice. Cube 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. Elisa Resconi 16
Summary þ Looking in the right direction and in the right moment is a good idea! þ From existing models: selection of proxy wavebands (HBL discussed) þ Photon light curves under compilation þ Photon light curve analysis with a global method (MLB) þ Selection of periods of possible neutrino emission: þ global & þ non arbitrary q Next: test on the data Elisa Resconi 17
- Slides: 17