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Rezo Shanidze

KM3NeT sensitivity to neutrino bursts from galactic supernovae. Rezo Shanidze. VLVnT08 - Toulon, Var, France 22-24 April 2008. Introduction. Is a n -burst from a core collapse of a massive star (Supernova type-II) in Galaxy detectable with KM3NeT ?

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Rezo Shanidze

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  1. KM3NeT sensitivity to neutrino bursts from galactic supernovae Rezo Shanidze VLVnT08 - Toulon, Var, France 22-24 April 2008

  2. Introduction • Is a n-burst from a core collapse of a massive star (Supernova type-II) in Galaxy detectable with KM3NeT ? • Layout of the talk: - Supernova neutrinos - The SNEWS project - SN-n in the neutrino telescopes - Studies for ANTARES - Estimations for KM3NeT - Summary and outlook ? The “Grand unified” neutrino spectrum from ASPERA Roadmap (phase I). Status and Perspectives of Astropartile Physics in Europe www.aspera-eu.org R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  3. Neutrinos from the core collapse • A. Burrows, • Annu. Rev. Nucl. Part. Sci, 40 (1990), 181 The neutrino luminosity (Ln) vs. time. Calculations of Myra&Burrows for 13 Mʘ progenitor star and 1.17 Mʘ iron core The time integrated neutrino number spectra vs. n-energy R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  4. SN neutrino interactions ne+p gn+ e+ (1) ne + 37Cl g37Ar + e- (4) ne + e-gne + e- (2) ne + 16O g16F + e- (5) nm,t+e-g nm,t+e- (3) ne + 16O g16N + e+(6) nl + 16O g16O* + nl(7) • The neutrino interaction cross-sections on the different targets vs. energy. • From A.Burrows, D.Klein, R.Gandhi, PR D45(1992), 3361 R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  5. Neutrinos from SN1987A K-II: K. Hirata et al, PRL 58(1987), 1490 IMB: R. M. Bionta el al, PRL 58(1987), 1494 Baksan: E.N. Alexeyev et al. PL B205(1988), 209 The neutrinos from SN1987A detected by Kamiokande-II, IMB and Baksan detectors. 23 Feb. 1987, 7:35:35 UT 18 h prior to the first optical sighting Exp. n-Events DT(sec.) E (MeV) K-II: 12 13 7.5 - 36 IMB: 8 6 20 - 40 Baksan: 5 9 12 - 23 R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  6. The SN Early Warning System http://snews.bnl.gov/ Expected SN rate in our Galaxy ~1-3 / century Important not to miss ! The goal of SNEWS is to provide the astronomical community with a prompt alert of the occurrence of a Galactic core collapse event. Technical description of the SNEWS: New J. Phys. 6(2004),114 [ astrpo-ph/0406214] The SN prompt alert g International network of n-experiments: Super-K, LVD, IceCube/AMANDA ( SNO until 2006) False alert rate of SNEWS < 1 century: Minimum acceptable level for 10s coincidence: 2 experiments, each with a false alarm rate ≤1 per week. R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  7. SN1987A signal in K-II The SN neutrinos in a neutrino telescope • First suggested for AMANDA: • F. Halzen, J. E. Jacobsen and E. Zas • Phys. Rev. D49(1994), 1758, • Ultratransparent Antarctic ice • as a supernova detector Predicted excess of N(p.e.) in a with NOM (10s): 11 - events in Kamiokande-II 2.14kton – target mass of Kamiokande-II 52 kpc - distance to SN1987A • J. Ahrens et al., (AMANDA Collaboaration), • Astropart. Phys. 16(2002), 345 • 302 OMs, 215 day (1997-1998) R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  8. AMANDA-II AMANDA-B10 IceCube 30 kpc IceCube sensitivity to the Galactic supernovae IceCube is sensitive to SN1987A type neutrino burst signal from a distance dSN < 30 kpc. (For 6s signal) Number of the fake SN alerts in IceCube < 15 y-1 The distribution of progenitor stars in the Milky Way, located within a distance r(kpc) from the Earth. ( Astropart. Phys.,16(2002), 345) R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  9. Supernova neutrinos in the undersea telescopes The main difference from other water/ice Cherenkov detectors: a complex sea environment - 40K, bioluminescence, currents, … ANTARES data: From Dec.2007 data taking with 10 lines (from 12). Constant monitoring of the deep sea environment. 3D virtual picture F.Montanet, CNRS/IN2P3 for Antares • The sources of “environmental photons” in ANTARES: • Steady, isotropic radiation from radioactive potassium 40K :~ 350 photons/cm2s. • Continuous bioluminescence ( from bacteria) • Localized bioluminescence bursts ( connected to the macroscopic organisms) R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  10. ANTARES environmental data Constant on-line monitoring of the sea environment is ANTARES: The values of current mean speed/ direction recorded in ANTARES. R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  11. Studies for the ANTARES telescope [1]S. Basa, ANTARES-PHYS-1998-03 [2]Y. Becherini, G. Ramadori, M. Spurio, ANTARES-PHYS-2002-002 • - GEANT 3 simulation of the cherenkov photons produced from positrons • in the inverse beta reaction from of the electron anti-n. • ANTARES configuration [2]: 900 OM/PMTs (10 line detector) • Different signals studied : 1, 2, 3 p.e hit rates, coincidence rates (c2) • SN (SN1987A type) • at D=10 kpc (GC) • Maximal sensitivity for • 1 p.e. signals • Above 3 s limit for • Dt< 1 s • negligible signal from • electron neutrinos 25 ms 100ms 10 s 1, 2, 3 - p.e. signal; 4,5 – C2 coincidence R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  12. The KM3NeT configuration For SN study: KM3NeT is a collection of OMs/PMTs. CDR options: 1) Standard: 10” Hamamatsu R7081 2) Directional 10” OM 3) Small: 3” Photonis XP53X2 ( for Multi-PMT (Flykt) OM ) 4) X-HPD based OM 4 3 2 The “reference detector”: 8325 Multi-PMT OM (15 x 15 x 37) R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  13. Possible SN signal in the KM3NeT telescope The KM3NeT detector performance evaluated for the reference detector. ANTARES g KM3NeT 5 s significance: < 1 event/ week 900 OM (10” PMT) 8325 OM (21 x 3” PMT) • Constant background from the K40 decays: • ~ 100 Hz cm-2/PMT : • ~ 40 kHz for 10” PMT/OM (ANTARES) • ~ 80 kHzfor Flykt-OM (21x0.09 = 1,8OMANTARES) KM3NeT 0.025 S=N/s ratio 0.050 0.5 • The S=N/s ratio for ANTARES and • KM3NeT vs time. in sec. • KM3NeT data is obtained by rescaling • the number of OMs: • 1) Same type of OM (▪) • 2) “Flykt-OM” () 0.1 10.0 20.0 ANTARES Time [ sec.] R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  14. Possible improvements • Time evolution of the SN signal (N/s ratio): • For example 2 trigger windows Dt1 and Dt2 and a correlation from the • time evolution of the SN signal can significantly increase the sensitivity • of KM3NeT to the n-bursts from the Galactic supernovae. Dt1 Dt2 OM with new PMTs ~ 1.7 x QE R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  15. ANTRES/ KM3NeT data model All data to shore concept: • Fast front-end electronics • High bandwidth • Software Trigger M. de Jong, KM3NeT CDR meeting. • “Supernova online trigger” • can be implemented on a • “on-shore” data, which • could run in parallel to • other triggers: • m - trigger • GC - trigger • GRB - trigger GRB trigger: All ANTARES hits (L0) detected in 120s are stored on a disk for GCN alert (~ 23 GB/trigger ) Same date can be used for “SN trigger” study in ANTARES. R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

  16. Summary and Outlook • First study indicates, that the KM3NeT neutrino telescope can • detect a supernova neutrino burst as a significant excess of OM • rates ( > 5s) in a short time interval (~10 s) , for a SN1987A type • supernova explosion at a distance < 10 kpc. • Constant monitoring of the sea environment will be necessary to keep • a “false supernova trigger” rate below a level acceptable by the • SNEWS network ( ≤ 1/week). • After the selection of KM3NeT neutrino telescope configuration, • the optical modules and the site, sensitivity to the neutrino bursts • from the supernovae can be studied with dedicated MC (GEANT4) • simulations. • The “ supernova neutrino trigger” can be designed and tested for • the ANTARES neutrino telescope, with an aim of providing the rate • below 1 trigger/week. R.Shanidze, VLVnT08 - Toulon, var, France, 22-34 April, 2008

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