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The High Energy Neutrino Sky as seen by Antares. Dorothea Samtleben Leiden University / NIKHEF, Amsterdam. Astrophysics Neutrinos are valuable cosmic messengers coming undeflected from cosmic sources Multimessenger approach exploited together with
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The High Energy Neutrino Sky as seen by Antares Dorothea Samtleben Leiden University / NIKHEF, Amsterdam
Astrophysics Neutrinos arevaluablecosmicmessengers comingundeflectedfromcosmicsources Multimessenger approachexploitedtogetherwith detectorsforelectromagneticradiationandgravitationalwaves New windowstotheUniversevia high energyneutrinos ParticlePhysics Atmosphereactsas ‘beam dump‘ forcosmicrays => Studies for - Prompt production (high energies) - Neutrino oscillations (lowenergies) Dark Matter WIMPs accumulate in massive objects (Sun, Earth) => possiblyannihilationsignals observable,
Gamma Ray Bursts Microquasars Supernova remnants Artist‘sview Neutrino sources Artist‘sview SN1006 Optical, radio, X-rays Highlyenergeticparticle accelerationneededtoexplain observedcosmicrayenergyspectrum - g from inverse Compton scattering - gfromsynchrotronradiationofelectrons - gfrompiondecay Neutrino fluxescanbederivedfromgemissionbyassumingpiondecayasoriginofg gg • Atmospheric neutrino flux ~ E-3 • Neutrino flux from cosmic sources ~ E-2
2p downward sensitivity assumed Mediterranean Field of View > 25% > 75%
The ANTARES Collaboration • University of Erlangen • Bamberg Observatory • Univ. of Wurzeburg • NIKHEF, • Amsterdam • Leiden • Utrecht • KVI Groningen • NIOZ Texel • ITEP,Moscow • MoscowStateUniv • IFIC, Valencia • UPV, Valencia • UPC, Barcelona • ISS, Bucarest 8 countries 34 institutes ~150 scientists+engineers CPPM, Marseille DSM/IRFU/CEA, Saclay APC, Paris LPC, Clermont-Ferrand IPHC, Strasbourg Univ. de H.-A., Mulhouse LAM, Marseille COM, Marseille GeoAzurVillefranche INSU-DivisionTechnique • LPRM, Oujda Univ./INFN of Bari Univ./INFN of Bologna Univ./INFN of Catania LNS-Catania Univ. Napoli Univ./INFN of Pisa Univ./INFN of Rome Univ./INFN of Genova 5
3D PMTarray Cherenkov light from m 42° Sea floor m nm interaction p, a nm p m nm nm Cosmicraysinteractwithatmosphere => showers, muons, neutrinos Neutrinos arrivefromcosmicsources Muonneutrinointeraction in Earth => Muonpassesdetector Also showersreconstructable => sensitive also tone,nt
12 lines mounted on the sea floor (2475m deep) • 25 storeys / line • 3 Photomultipliers / storey ANTARES detector PMT PMT 40 km to shore
~105atmosphericmuons per day ~5 atmosphericneutrinos per day Maximum likelihood fit usinghitpositionsandtimes (nanosecondresolution) Track reconstruction Quality of track fit can be used to decrease misreconstruction => Use likelihood value and angular error estimate
Track reconstruction Track resolution degrees In pointsourceanalysis
Analysis 2007-2010 data (813 days), 4 108events, 3058 neutrinocandidates Skymapof p-values in equatorialcoordinates Point sourceanalysis Most significantcluster, p-value=0.026 (α, δ) = (−46.5◦, −65.0◦) 5(9) eventsarewithin 1(3) degreess (2.2s) Ap J 760:53 (2012)
Study for 51 potential neutrinosources: • Nosignificantexcess => upperlimits • Best limitsford<-30 Fluxlimit
Diffuse neutrinoflux Distribution of R in data in comparisonto MC expectations Simulation ofenergyestimator R Data 2007-2009, corresponding to 335 active days Distinctionof diffuse fluxfromatmosphericneutrinosbyenergy (harderspectrumexpectedfromsources) Energyestimator R based on hitmultiplicity on Photomultipliers Prompt neutrinos (RPQM) E-2 flux at limit
Diffuse neutrinoflux E2F(E)90%= 5.3 10-8GeV cm-2 s-1 sr-1 20 TeV<E<2.5 PeV 90% upper limit assuming E-2 flux spectrum Physics Letters B 696 (2011) 16
2008-2011 data used Two different energy estimators: - dE/dx as evaluatedfrom charge collected in the detector - Combined likelihood for hit/no-hit for all OMs L: length e: efficiency Atmosphericneutrinospectrum Atmospheric energy spectrum by unfolding measured spectrum New diffuse limit using dE/dx estimator E2F(E)90%= 3.2 10-8GeV cm-2 s-1 sr-1 45 TeV<E<6.3 PeV 90% upper limit assuming E-2 flux spectrum PRELIMINARY
Fermi Bubbles: • Excess of ɣ-rays seen in Fermi data in extended distinct regions • (each ~ 25000 light-years) • Homogenous intensity • Sharp edges • Flat E-2 spectrum • (between 1 and 100 GeV) Neutrinos from Fermi Bubble Galactic coordinates • Background estimated from • average of 3 equivalent regions • Event selection optimized for best model rejection factor Good visibility for ANTARES
Upper limits ANTARES preliminary 50 TeV cutoff 100 TeV cutoff 500 TeV cutoff No cutoff Data 2008-2011 Fermi Bubbles zone: Nobs = 16 Excluding Bubbles zone: <Nbg> = 11 = (9+12+12)/3 No significant excess → set upper limits PRELIMINARY Solid: 90% CL limits Dotted: model prediction Dotted: different models Upper limits with respect to different models
c rc <sv> Searchfor Dark Matter n m • Dark Matter WIMPs accumulate in heavy objects (Sun, Galactic Center, Earth) • Capture/Annihilation in equilibrium at the Sun core • Annihilation e.g. in bb/tt/WW -> n+.. • Model-independent event simulation using WIMPSIM • Interactions in the Sun and flavor oscillation, regeneration of t in the Sun taken into account
c rc <sv> Searchfor Dark Matter n m Neutrino candidates in the direction towards the sun (angular distance y) Angular resolution (median) c2 based track reconstruction efficient for low energies Different detector configurations kinematics
Spin-independent cross-section limit for ANTARES 2007-2008 in CMSSM Dark Matter limitsfromthesun For CMSSM: Branchingratios = 1 (for WW, bb, ττ) (Large variationof branchingratiosover parameterspace) PRELIMINARY
Spin-dependentcross-section limit for ANTARES 2007-2008 in CMSSM Dark Matter limitsfromthesun For CMSSM: Branchingratios = 1 (for WW, bb, ττ) (Large variationof branchingratiosover parameterspace) PRELIMINARY
Neutrino oscillation Simulation of reconstructedneutrinos Single Line • Low energyatmosphericneutrinosimportant • Baseline L fromzenith angle q • Energyestimatefromtracklength • Different trackreconstructionusing multi-lineand single-lineevents (onlyzenithreconstructed) Multi Line Dashed: withoscillation
Data Best Fit No oscillations For maximal mixing m2=(3.1±0.9) 10-3 eV2 Antares, K2K, Minos, SuperK PhysLettB 714, 224 (2012)
First Funding already available to allow start of construction 2013-15 Building/Deployment of first batch of detectors 2015++ Completion of Detector Deep Sea Research Infrastructure in the Mediterranean Sea hosting a multi cubic kilometer neutrino telescope Locations of the three pilot projects: ANTARES: Toulon NEMO: Capo Passero NESTOR: Pylos KM3NeT
1 building block 800 m Configuration Multiple building blocks 640 strings (in total) 20 storeys/string => 12800 DOMs 860m New detectorconcept: Spherewith 31 PMTs - gooddirectionality - singlephotoncounting Track resolution 0.1deg @ TeV
First light of sphere with 31 PMTs in Antares Rate histogram for multiplicity of coincidences -> seeing first muons! Configuration Multiple building blocks 640 strings (in total) 20 storeys/string => 12800 DOMs 860m New detectorconcept: Spherewith 31 PMTs - gooddirectionality - singlephotoncounting Track resolution 0.1deg @ TeV
Neutrino telescope in seawatersuccessfullyestablishedwith high angular resolution Varietyofphysicsanalysesunderway, firstresultspublished Large severalcubickilometerarray Km3NeT planned in theMediterraneanSea Constructionoffirst KM3NeT detectionunitsunderway First light withnewopticalmodule in Antares! => NEW WINDOW TO THE UNIVERSE BECOMES AVAILABLE