1. Search for Neutrinos from GRBs with AMANDA and IceCube Alexander Kappes University Wisconsin-Madison For the IceCube Collaboration 6 th International Workshop on New Worlds in Astroparticle Physics 6. – 8. September 2007, Faro Portugal

2. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20072 Outline of Talk The AMANDA and IceCube detectors (see talk of D. Bertrand) Gamma-Ray Bursts and models of neutrino production Search for GRBs with neutrino telescopes Latest results from AMANDA IceCube and GRBs

3. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20073 Gamma-Ray Bursts Very intense, short (0.1–1000 s) g-ray flashes Known since late 1960s (discovered by US Vela nuclear test detection satellite)‏ Major progress in 1990s with BATSE and Beppo Sax (two categories, isotropic distribution, distance measurement)‏ 2 Vela satellites BATSE on CGRO short long

4. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20074 Gamma-Ray Bursts Additional observations: Long GRBs (LGRBs, T > 2 s): Occur mainly in star forming regions Often optical supernova (SN) observed Interpreted as core collapse SNe Short GRBs (SGRBs, T < 2 s): Occur mainly in outer regions of older galaxies By factor ~10 lower luminosity than LGRBs Interpreted as accreting Black Holes in merging binary systems But also GRBs with “mixed” features observed (e.g., GRB060624)

5. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20075 Development of Long GRBs Progenator star with > 10 M Sun and Fe core ~2 M Sun Formation of black hole after collapse Accretion of envelope material on black hole creates relativistic jet along rotation axis Jet propagates through envelop (O 100 s)‏ Jet emerges from progenitor envelop and produces gamma-ray signal Artist's view of a GRB Collapses to highly magnetized pulsars may also produce jets Emerging jet (Zhang & Woosley)‏

6. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20076 Models of Neutrino Production in (Long) GRBs Fireball model p + p/g p + X p ± n m + m m n m + n e + e n oscillations: (n e,n m,n t ) = (1 : 1 : 1) Precursor ~-100 sT0T0 Precursor (Dt~100 s): Jet collides with star envelop TeV neutrinos (Not visible in g-rays)‏ [Meszaros & Waxman, 2001] ~100 s> 1000 s Main burst (Dt~100 s): Internal shocks in jet 100 TeV – PeV neutrinos [Waxman & Bahcall, 1997] [Razzaque et al. 2003] [Murase & Nagataki 2006] Afterglow (Dt > 1000 s): Flares ⇒ PeV neutrinos [Dermer 2001] Collision with interstellar medium ⇒ EeV neutrinos [Waxman & Bahcall 2000]

7. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20077 Neutrino Flux Predictions main burst afterglow precursor Neutrinos from GRBs (all flavors)‏ failed GRBs Waxman & Bahcall Murase & Nagataki Meszaros & Waxman Razzaque et al Waxman multiplied with E 2 ! flavor ratio at Earth (1 : 1 : 1)‏ successfull GRBs Only average fluxes → large burst-to-burst fluctuations ! Purely electromagnetic models (Poynting-flux) ⇒ no neutrinos (Lyutikov and Blandford 2003)‏

8. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20078 GRB Detection in Neutrino Telescopes Two basic “channels”: Muons: track of hits ⇒ good angular resolution (IceCube ~1° for E n > 1 TeV)‏ Cascades (all flavors): concentric hits ⇒ no direction information but low atm. background Neutrino effective area rises strongly with energy cross section increases light output increases n m :muon range grows; 14 km @1 PeV ! ⇒ Interesting E range TeV – PeV (afterglow flux probably very low) IceCube 80 strings @ trigger level (preliminary)‏ muon neutrinos electron neutrinos

9. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 20079 Event Rates in Neutrino Telescopes GRB neutrinos in short time window ( ~ 50 s) assuming 670 bursts per year ⇒ GRB neutrinos during burst ~10 -3 Hz from specific position in sky (1° x 1° search window) ⇒ atm. muons ~10 -2 Hz, atm. neutrinos ~10 -7 Hz southern hemisphere northern hemisphere Triggered in IceCube with 22 strings: atmospheric muons (500 Hz)‏ atmospheric neutrinos (10 -2 Hz)‏ GRB muon neutrinos (WB, integrated) (10 -6 Hz)‏ very clean signal for northern hemisphere reduced sensitivity for southern hemisphere

10. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200710 Search Strategies GCN triggered searches (cascades, muon): profit from known time (and direction)‏ Untriggered “sliding window” searches (cascades): large fraction of GRBs not observed by satellites possible large population of “choked GRBs” not visible in g-rays (jet doesn't emerge from progenitor envelop ⇒ only precursor neutrinos)‏ sliding window: 1h on-time (T90)‏ precursor noff-time always blind T GRB 10 min time events 3 evts 2 evts 1 evt

11. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200711 Latest Results from AMANDA II Muon channel: Model Years# Bursts Satellite(s)bkg (exp)obs. main burst1997–2003 419BATSE+IPN 1.7 0 precursor2001–2003 60 IPN 0.2 0 Note: 0.8 events for Waxman-Bahcall GRB (main burst) flux expected A. Achterberg etal, ApJ in press (astro-ph/0705.1186)‏ Cascade channel: Method Years# Bursts Satellite(s)bkg (exp)obs. triggered 2000 73 BATSE 0.03 0 rolling2001–2003 – – – – two window sizes: 1 and 100 s number of triplets and doublets compatible with background A. Achterberg etal, ApJ 664:397, 2007 (astro-ph/0702265)‏

12. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200712 All Flavor GRB Limits from AMANDA II Limits from triggered searches assume ~700 bursts per year AMANDA starts to exclude flux models! Cascade search in IceCube much more competitive (factor 70 in instrumented vol.) Eff. volume (cascades) grows faster than eff. area (muon)! Cascade searches (trig + roll)‏ only rolling Muon searches (only trig)‏

13. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200713 GRB Detection in the IceCube Era GCN: Network of satellite and ground based observatories Satellites send GRB alerts to ground stations for follow up observations Swift currently workhorse (~100 GRBs per year) Burst Alert Monitor: FoV=1.4 sr; E range 15–150 keV GLAST (satellite): Launch planned Jan. 2008; science from March '08!? GBM (Burst Alert Monitor): FoV = 9.5 sr; E range: 8 keV–25 MeV LAT (Large Area Telescope): FoV = 2.4 sr; E range: 20 MeV–300 GeV ! Expected to observe ~200 GRBs per year GCN network GLAST

14. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200714 ANTARES Design Study KM3NeT? Accumulated exposure @ 100 TeV AMANDA onlyIceCube muon eff. area (km 2 yr)‏ IceCube: Status and Further Construction 2007:22 strings; already 6 times larger than AMANDA 2008:36+ (40) strings; 2011:80 strings (full detector)‏ AMANDA IceCube-22

15. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200715 IceCube: The GRB Filter Only limited satellite bandwidth for data transfer (~30 GB per day) ⇒ triggered data has to be filtered (all data written to tape) ⇒ reduce atm. muons by zenith cut (typical > 70°) ⇒ no sensitivity to GRBs in southern sky Dedicated GRB filter writes out all data ±1 h around GCN trigger Trigger Buffer (2 d)‏ GRB Buffer (90 d)‏ GCN GRB South Pole Computer e-mail (Iridium, 24/7)‏ 2 h per GRB Online proces- ing planned TDRSS satellite Data Warehouse (North) In operation since June 2007

16. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200716 Sensitivity of IceCube to GRBs IceCube-80 more than a magnitude more sensitive than AMANDA larger effective area + better angular resolution signal efficiency for AMANDA 25–75% 3s sensitivity for Waxman-Bahcall GRB flux with ~100 (~300) detected bursts in muon (cascade) channel (GLAST ~200 bursts per year, 4 p)‏ IceCube is looking both in the northern and the southern sky AMANDA IceCube-22 IceCube-40 IceCube-80

17. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200717 Optical Follow-up Observations Potentially many choked GRBs (all SNe?) (not visible in X-rays) Increase chance to detect GRB by optical observation of afterglow/SN Look for neutrino doublets within spatial (~3°) and time (~100 s) window ⇒ pointing resolution ~0.5° ⇒ ~30 evts/yr from background Optical follow-up observations: 80% of IceCube PSF covert by telescope with 2° x 2° FoV many fully automatic telescopes exist worldwide ROTSE III: 4 x 0.45 m FoV: 2 O x 2 O  rapid follow-up Others: RoboNet, Stella … Preliminary Feasibility currently under study

18. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200718 Summary AMANDA started to exclude GRB neutrino flux models with integrated exposure of 0.1 km 2yr (420 bursts)‏ IceCube's integrated exposure will reach 1(3) km 2yr in 2009 (2011) Full IceCube detector reaches 3 s sensitivity for Waxman-Bahcall GRB flux with ~100 triggered bursts (from 2008 on GLAST + Swift will detect ~200 GRBs per year)‏ IceCube will be able to observe current GRB model neutrino fluxes within a few years There are exciting times ahead!

19. Alexander Kappes, UW-MadisonAstro 2007, Faro Portugal, 6. - 8. Sept. 200719 Cascade searches (trig + roll)‏ only rolling Muon searches (only trig)‏