1. Alexander Kappes (E. Strahler, P. Roth) ECAP, Universität Erlangen-Nürnberg for the IceCube Collaboration 2009 Int. Cosmic Ray Conf., Łódź, 11.06.2009 Search for neutrinos from GRBs with IceCube 22-strings

2. Alexander Kappes, ICRC2009, Łódź July 2009 2 Detection of Cherenkov light from charged secondary particles Requires large transparent detector volumes → natural resources of ice/water Detection of high-energy neutrinos muon νμνμ nuclear reaction cascade

3. Alexander Kappes, ICRC2009, Łódź July 2009 3 The IceCube neutrino observatory IceTop air shower detector IceCube 80 strings (4800 PMTs) instrumented volume: 1 km 3 status: 58 strings installed DeepCore 6 additional strings more densely instrumented first string installed in 2008/09 Low-energy physics, E < 1 TeV (WIMPs,... ) 1450 m 2450 m

4. Alexander Kappes, ICRC2009, Łódź July 2009 4 Flash of gamma rays (E ~ MeV) → observed by satellites (e.g. Fermi, SWIFT) GRBs distributed isotropically → extra-Galactic Cosmological distances up to z = 8.6 (billions light years) Gamma-ray bursts Fireball model Precursor ~-100 sT0T0 ~100 s> 1000 s 10 12 eV neutrinos 10 15 eV neutrinos 10 18 eV neutrinos Prompt

5. Alexander Kappes, ICRC2009, Łódź July 2009 5 Satellite triggered searches (profit from known time + direction) Low number of events per burst expected ➞ burst stacking Off-time data used as background Search method On-time (blind)Off-time T0T0 prompt precursor (~100 s) wide window O (-1 h to +3 h) background

6. Alexander Kappes, ICRC2009, Łódź July 2009 6 Neutrino fluence: prompt phase Data period: June 2007 - April 2008 (IceCube 22 strings) 41 satellite-triggered northern bursts (mainly Swift) → for southern bursts see Paper ID515 Calculation of individual burst spectra (fireball model) preliminary

7. Alexander Kappes, ICRC2009, Łódź July 2009 7 Neutrino fluence: precursor and wide window Precursor: -100 s before prompt window -Interaction of protons with progenitor envelope (Razzaque, Meszaros & Waxman, Phys.Rev.D 68:628) Wide window: -model independent (E -2 assumed) Precursor neutrino flux pp pγ

8. Alexander Kappes, ICRC2009, Łódź July 2009 8 Two methods used -Unbinned likelihood method -Binned method → unbinned more sensitive Expected events -prompt: average WB ~0.7 individual spectra ~0.03 -precursor: ~0.5 No excess found in any of the three windows IceCube 22-strings: muon analyses Discovery potential prompt (unbinned method) preliminary

9. Alexander Kappes, ICRC2009, Łódź July 2009 9 IceCube 22-strings: upper limits precursorprompt Final AMANDA limits (Waxman & Bahcall, PRL 78, 2292) IceCube 22 strings Models: prompt: sum of individual spectra precursor: Razzaque, Meszaros & Waxman Phys.Rev.D 68:628 preliminary

10. Alexander Kappes, ICRC2009, Łódź July 2009 10 Perspectives with IceCube 80 strings Expect that IceCube 80-strings will be 3-4 times more sensitive than IceCube 22-strings With Fermi number of observed GRBs will be ~3 times larger (200-300 per year) IceCube will be able to detect Waxman-Bahcall or similar GRB fluxes within the next years

11. Alexander Kappes, ICRC2009, Łódź July 2009 11 Summary IceCube 70% completed (completion planned for 2011) Current IceCube GRB analyses: -Analysis of IceCube 22-string data finished (triggered prompt + precursor + wide-window searches) -No deviation from background detected With growing IceCube detector + Fermi/Swift good chances to identify first cosmic neutrinos