Summary WG4 – Neutrino Astronomy experimental part Mieke Bouwhuis: Results from ANTARES Georgio Riccobene: Results from NEMO and KM3NeT Dave Besson: Radio detection Doug Cowen: Tau neutrino detection in IceCube Ty de Young: Novel tau signatures in neutrino telescopes Julia Becker:AMANDA flux results and interpretation Elisa Resconi:IceCube: multiwavelength approach Lutz Köpke University of Mainz + many posters extend reach:(sky coverage, energy coverage, -id …) improve sensitivities: (stacking, -  correlation…)

ANTARES Mieke Bouwhuis reconstruction with one line full detector data taking 2007+

“typical” downgoing muons single muon probably muon bundle … also several upgoing muons

Zenith angle of atmospheric muons

Status of the NEMO Project Georgio Riccobene Capo Passero 3450 m Toulon 2400 m Pylos 3800:4000 m ANTARES NEMO NESTOR Advantages: Deep, low bioluminescence, weak currents, little sedimentation full tower 2007 TDR KM3NeT 2009 cost < 200 M€

NEMO-km 3 detector design study 20 m 40 m …similar number of PMT’s, towers as IceCube … 100 km from shore Modular, rigid structures with 4 PMTs that unfolds … Philosophy: reduce number of structures and underwater connections; operate by ROV

Radio detection Points of cautions: 1)presented upper limits can `float’ horizontally (no energy resolution), 2) different model parameters used for different modes, 3) 90% vs. 95% C.L. limits, 4) results depend on binning Future: Hybrid detectors (optical, radio, acoustic) David Besson

wild ideas florish … Europa radio antenna

Advantages of Tau Neutrinos  appreciable  flux at source e :  :  ::1:2:0  flux rate at detector e :  :  ::1:1:1  for E > ~1 TeV  low background for some topologies atmospheric neutrino oscillation and open charm negligible …  rich set of signatures …  4  acceptance at E(  ) < ~ eV due to  regeneration  very clean tag for cosmological neutrino origin ! …. but geometrically coarse detectors, low event rates, limited energy range,  branching ratio … D. Cowen & Ty de Young

 detection with IceCube   : 50 m/PeV νN interaction  decay “classic double bang” Learned & Pakvasa 1995 “Lollipop” – half of a double bang Beacom, Bell, Hooper, Pakvasa & Weiler relatively dim track

Tau topologies..look at green topologies ….a first look

Double Pulse topology fully simulated waveform 75 TeV  (~300 TeV  ):   cascade 1   cascade 2  sum  MC truth DOM Waveform  discrimination not always that obvious … Toy-MC: Looks encouraging needs full simulation!

l l l l l l γ e+e+ e-e- hadronic shower ( = μ,τ) l EM showers μ Energy loss mechanisms τ

Muons are brighter than  ’s τ μ → track suddenly brightens Can we see it? Sugar daddy topology track length sufficient Ty de Young, Cowen, Razzaque, astro-ph/ energy resolution

Search for single point sources 90% confidence level flux upper limits for the northern hemisphere in 0.5 deg bins (15% systematic error included) AMANDA: 4282 events in 5 years  no significant signal  limit map improvement due to stacking 6x GeV cm -2 s -1 Source stacking (model-dependent!!) allows for <O(10) sensitivity improvement … preliminary Julia Becker

Nr of  Time d  atm (t)/dt = 1 / year 3 o sky-bin 1  / day sky-bin ~ How can we discriminate these events ? What can we learn from photon photon observations? Photon Rate (counts/sec) Time correlation studies Elisa Resconi

Careful! Very low statistics!  test well defined hypotheses, do blind analyses, define statistical interpretation beforehand! sample, time periods determined a priori in the time periods / atmospheric expected  intelligently select sources to monitor  obtain/analyze/interpret photonic data (x-ray, gamma) x-ray monitoring continuous TeV-gamma sporadic …. “orphans”: TeV-gamma but no x-ray  define and “code” definition of a flare  reconstruct neutrino online To turn neutrino detector to a all-sky 24/24 monitor and trigger: 3 month test AMANDA/Magic this year…

Elisa Resconi All-Sky-Monitor, Maximum-Likelihood-Blocks, Characteristic level zoom Mkn 421 Characteristic level (band) Depends on: source + detector Elevated levels or flares : ~ 15 % + 3  R char TeV-  curves very sporadic, historical light curves: under construction

AMANDA Diffuse limits AMANDA 4 year limit assuming E -2 : Hill et al., Neutrino 2006 Nellen,Mannheim & Biermann 1993 Stecker & Salamon 1996 (x-ray) Differential limits difficult to obtain  limits depend on assumed spectral index …exclude Stecker&Salomon 96 AGN flux, but not Stecker 2005 Stecker 2005 (  -ray)

Diffuse flux of TeV Blazars conservative estimate: Both,  visible (x < 0.3) only visible (1 < x < 10) x diffuse flux flux sources up to redshift zmax absorption factor

Maximum contribution from TeV blazars astro-ph/ Test specific models!

Experimental summary(summary) of WG4 Extend reach: –Northern hemisphere detectors (Antares 2007+, TDR km3NET 2009) –Further extend energy range (radio, acoustics ….) –Ideas to identify  -neutrinos in many topologies Extend sensitivities: –stacking techniques (assume analogous behaviour,  - correlation) –Correlation with x-ray or TeV  flares; -telescope triggers? –Investigate specific models