1 / 18

Imaging the Neutrino Universe with AMANDA and IceCube

Imaging the Neutrino Universe with AMANDA and IceCube. Motivations for neutrino astronomy Selected AMANDA results IceCube: Status and Plans. David Hardtke University of California, Berkeley. Lake Louise Winter Institute February 2005. Neutrino Astronomy. Neutrino Production and Detection.

lilika
Download Presentation

Imaging the Neutrino Universe with AMANDA and IceCube

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Imaging the Neutrino Universe with AMANDA and IceCube Motivations for neutrino astronomy Selected AMANDA results IceCube: Status and Plans David Hardtke University of California, Berkeley Lake Louise Winter Institute February 2005

  2. Neutrino Astronomy

  3. Neutrino Production and Detection • Candidate astrophysical accelerators for high energy cosmic rays: • Active Galactic Nuclei • Gamma-Ray Bursts • Neutrino production at source: p+ or p+p collisions • Neutrino astronomy requires large detectors • Low extra-terrestrial neutrino fluxes • Small cross-sections dN/dEE-2 dN/dEE-3.7

  4. South Pole Dome road to work AMANDA Summer camp 1500 m Amundsen-Scott South Pole station 2000 m [not to scale]

  5. Neutrino Detection in Polar Ice South Pole ice: event reconstruction by Cherenkov light timing O(km) long muon tracks ~15 m cascades Longer absorption length  larger effective volume

  6. Atmospheric Neutrinos Muon Neutrino Flux Maximum E-2 contribution PRELIMINARY • AMANDA test beam(s): atmospheric  (and ): • Neural Net Energy Reconstruction (upgoing ) • “Unfold” to get neutrino Energy Spectrum E2(E) < 2.6·10–7 GeV cm-2 s-1 sr-1 Limit on diffuse E-2flux (100-300 TeV):

  7. Diffuse Extra-terrestrial Neutrino Search After optimized cuts: Nobs = 1 event Natm  = 0.90 Natm  = 0.06 ± 25%norm +0.69 -0.43 +0.09 -0.04 Astroparticle Physics 22, 127 (2004) “Cascade” search: 4  coverage Signal Background

  8. Diffuse PeV-EeV neutrino search m tracks • Earth opaque to PeV neutrinos  look horizontally • Look for superbright events (large number of Optical Modules with hits) • Train neural network on dN/dE  E-2 signal Simulated UHE event Nobserved = 5 Nbackground = 4.6  1.2 Astroparticle Physics 22, 339 (2005)

  9. Summary of Diffuse Flux Limits All-flavor Flux Limits vs. Model Predictions Cascades Unfolded Atmospheric (x3) Horizontal UHE Models Excluded: S91 (Stecker et al) AGN Core S96 (Stecker et al) AGN Core (updated) P97 (Protheroe) AGN Jet Barely Alive: M 95 (Mannheim) AGN Jet

  10. Neutrino Point Source Search • Four Year (2000-2003) analysis • Optimize cuts in each declination band assuming E-2 spectrum • 3329 upgoing  events • < 5% fake events

  11. “Hot spot” search Significance Map: Largest excess is 3.35  Assess statistical significance using random skymaps. No statistically significant hot spots !

  12. Round Up the Usual Suspects • Search for high energy neutrino excess from known gamma emitting sources: TeV Blazars GeV Blazars Supernova Remnant No Statistically Significant Excess from 33 Targeted Objects

  13. IceCube • 80 strings with 60 optical modules (OMs) on each • Effective Volume ≈ 1 km3 • Size required to see “guaranteed” neutrino sources • Surface Array (IceTop) • PMT signal digitization in ice.

  14. IceCube Sensitivity

  15. IceCube Status January 2005: First String Deployed!

  16. Conclusions • No Extra-terrestrial neutrino signal observed • Diffuse flux searches (TeV - EeV) • Point source searches • No statistically significant hotspots • No evidence for high-energy neutrino emission from gamma emitting objects • IceCube under construction • 2-3 order of magnitude improvement in sensitivity

  17. IceCube Simulated Events Eµ=10 TeV ~300m for PeV t e  e E = 375 TeV

  18. How large is IceCube? AMANDAII 300 m Super K 1500 m 50 m 2500 m

More Related