Presentation on theme: "UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Neutrino Astrophysics with IceCube KAEL HANSON UNIVERSITÉ LIBRE DE BRUXELLES 12 TH MARCEL GROSSMANN MEETING."— Presentation transcript:
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Neutrino Astrophysics with IceCube KAEL HANSON UNIVERSITÉ LIBRE DE BRUXELLES 12 TH MARCEL GROSSMANN MEETING 13 – 18 JULY 2009 PARIS
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Connecting Neutrinos and Gravity CR acceleration in compact objects – accelerators are essentially all gravity- powered. Low interaction cross-section of neutrinos makes them excellent probes deep inside massive objects without reprocessing in or around object. Supernova explosions Neutrinos play important role in cosmology and JULY 2009 MG XIISLIDE 2
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Two-minute IceCube quiz JULY 2009 MG XII SLIDE 3 Easy Question: Is IceCube a TeV-scale neutrino observatory? Answer: Yes, of course. IceCube was designed to optimize the response to ν-induced µ in energy range between 1-100 TeV (A eff,ν 10 m 2 at 10 TeV). Muon energy loss related to E µ above 1 TeV. Angular resolution of 1°. Harder Question: Is IceCube a GeV-scale neutrino observatory? Answer: Also yes. With the addition of the DeepCore detector, the threshold energy is lowered from 100 GeV to 10 GeV. In addition, 4π solid angle acceptance possible due to shielding power of surrounding detector. Trick Question: Is IceCube an MeV-scale neutrino observatory? Answer: Yes and no. By turning the array into a simple photon counting system, it is possible to detect bursts of low-energy neutrinos emitted by supernova explosions. Discrete events are lost – you are left with a rate-vs-time. However, the effective volume is extremely large and with the resulting high statistics quite a bit of information can be extracted.
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Motivation: why the supernova connection? Only a handful of confirmed astrophysical sources of neutrinos – Neutrinos from the Sun – Atmospheric neutrinos – Neutrinos from 1987A supernova explosion Measurement of temporal profile of neutrino burst from SNe in our galaxy would be invaluable data for explosion models. Realtime monitoring into worldwide burst alert network can give hours of advance warning to optical observers. Finally, de gustibus non est disputandum JULY 2009 MG XIISLIDE 4
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE The IceCube Collaboration JULY 2009 MG XII SLIDE 5 R. Abbasi 24, Y. Abdou 18, T. Abu-Zayyad 29, J. Adams 13, J. A. Aguilar 24, M. Ahlers 28, K. Andeen 24, J. Auffenberg 35, X. Bai 27, M. Baker 24, S. W. Barwick 20, R. Bay 7, J. L. Bazo Alba 36, K. Beattie 8, J. J. Beatty 15,16, S. Bechet 10, J. K. Becker 17, K.-H. Becker 35, M. L. Benabderrahmane 36, J. Berdermann 36, P. Berghaus 24, D. Berley 14, E. Bernardini 36, D. Bertrand 10, D. Z. Besson 22, M. Bissok 1, E. Blaufuss 14, D. J. Boersma 24, C. Bohm 30, J. Bolmont 36, O. Botner 33, L. Bradley 32, J. Braun 24, D. Breder 35, T. Castermans 26, D. Chirkin 24, B. Christy 14, J. Clem 27, S. Cohen 21, D. F. Cowen 32,31, M. V. D'Agostino 7, M. Danninger 30, C. T. Day 8, C. De Clercq 11, L. Demirörs 21, O. Depaepe 11, F. Descamps 18, P. Desiati 24, G. de Vries-Uiterweerd 18, T. DeYoung 32, J. C. Diaz-Velez 24, J. Dreyer 17, J. P. Dumm 24, M. R. Duvoort 34, W. R. Edwards 8, R. Ehrlich 14, J. Eisch 24, R. W. Ellsworth 14, O. Engdegård 33, S. Euler 1, P. A. Evenson 27, O. Fadiran 4, A. R. Fazely 6, T. Feusels 18, K. Filimonov 7, C. Finley 24, M. M. Foerster 32, B. D. Fox 32, A. Franckowiak 9, R. Franke 36, T. K. Gaisser 27, J. Gallagher 23, R. Ganugapati 24, L. Gerhardt 8,7, L. Gladstone 24, A. Goldschmidt 8, J. A. Goodman 14, R. Gozzini 25, D. Grant 32, T. Griesel 25, A. Groß 13,19, S. Grullon 24, R. M. Gunasingha 6, M. Gurtner 35, C. Ha 32, A. Hallgren 33, F. Halzen 24, K. Han 13, K. Hanson 24, Y. Hasegawa 12, J. Heise 34, K. Helbing 35, P. Herquet 26, S. Hickford 13, G. C. Hill 24, K. D. Hoffman 14, K. Hoshina 24, D. Hubert 11, W. Huelsnitz 14, J.-P. Hülß 1, P. O. Hulth 30, K. Hultqvist 30, S. Hussain 27, R. L. Imlay 6, M. Inaba 12, A. Ishihara 12, J. Jacobsen 24, G. S. Japaridze 4, H. Johansson 30, J. M. Joseph 8, K.-H. Kampert 35, A. Kappes 24,a, T. Karg 35, A. Karle 24, J. L. Kelley 24, P. Kenny 22, J. Kiryluk 8,7, F. Kislat 36, S. R. Klein 8,7, S. Knops 1, G. Kohnen 26, H. Kolanoski 9, L. Köpke 25, M. Kowalski 9, T. Kowarik 25, M. Krasberg 24, K. Kuehn 15, T. Kuwabara 27, M. Labare 10, S. Lafebre 32, K. Laihem 1, H. Landsman 24, R. Lauer 36, D. Lennarz 1, A. Lucke 9, J. Lundberg 33, J. Lünemann 25, J. Madsen 29, P. Majumdar 36, R. Maruyama 24, K. Mase 12, H. S. Matis 8, C. P. McParland 8, K. Meagher 14, M. Merck 24, P. Mészáros 31,32, E. Middell 36, N. Milke 17, H. Miyamoto 12, A. Mohr 9, T. Montaruli 24,b, R. Morse 24, S. M. Movit 31, R. Nahnhauer 36, J. W. Nam 20, P. Nießen 27, D. R. Nygren 8,30, S. Odrowski 19, A. Olivas 14, M. Olivo 33, M. Ono 12, S. Panknin 9, S. Patton 8, C. Pérez de los Heros 33, J. Petrovic 10, A. Piegsa 25, D. Pieloth 17, A. C. Pohl 33,c, R. Porrata 7, N. Potthoff 35, P. B. Price 7, M. Prikockis 32, G. T. Przybylski 8, K. Rawlins 3, P. Redl 14, E. Resconi 19, W. Rhode 17, M. Ribordy 21, A. Rizzo 11, J. P. Rodrigues 24, P. Roth 14, F. Rothmaier 25, C. Rott 15, C. Roucelle 19, D. Rutledge 32, D. Ryckbosch 18, H.-G. Sander 25, S. Sarkar 28, S. Schlenstedt 36, T. Schmidt 14, D. Schneider 24, A. Schukraft 1, O. Schulz 19, M. Schunck 1, D. Seckel 27, B. Semburg 35, S. H. Seo 30, Y. Sestayo 19, S. Seunarine 13, A. Silvestri 20, A. Slipak 32, G. M. Spiczak 29, C. Spiering 36, M. Stamatikos 15, T. Stanev 27, G. Stephens 32, T. Stezelberger 8, R. G. Stokstad 8, M. C. Stoufer 8, S. Stoyanov 27, E. A. Strahler 24, T. Straszheim 14, K.- H. Sulanke 36, G. W. Sullivan 14, Q. Swillens 10, I. Taboada 5, A. Tamburro 29, O. Tarasova 36, A. Tepe 35, S. Ter-Antonyan 6, C. Terranova 21, S. Tilav 27, P. A. Toale 32, J. Tooker 5, D. Tosi 36, D. Turčan 14, N. van Eijndhoven 34, J. Vandenbroucke 7, A. Van Overloop 18, B. Voigt 36, C. Walck 30, T. Waldenmaier 9, M. Walter 36, C. Wendt 24, S. Westerhoff 24, N. Whitehorn 24, C. H. Wiebusch 1, A. Wiedemann 17, G. Wikström 30, D. R. Williams 2, R. Wischnewski 36, H. Wissing 1,14, K. Woschnagg 7, X. W. Xu 6, G. Yodh 20, S. Yoshida 12 1.RWTH Aachen University 2.University of Alabama 3.University of Alaska Anchorage 4.Clark-Atlanta University 5.Georgia Institute of Technology 6.Southern University 7.University of California, Berkeley 8.Lawrence Berkeley National Lab 9.Humboldt-Universität zu Berlin 10.Université Libre de Bruxelles 11.Vrije Universiteit Brussel 12.Chiba University 13.University of Canterbury 14.University of Maryland 15.Ohio State University 16.Ohio State University 17.TU Dortmund University 18.University of Ghent 19.Max-Planck-Institut für Kernphysik 20.University of California, Irvine 21.École Polytechnique Fédérale 22.University of Kansas 23.University of Wisconsin, Madison 24.University of Wisconsin, Madison 25.University of Mainz 26.University of Mons-Hainaut 27.Bartol Research Institute 28.University of Oxford 29.University of Wisconsin, River Falls 30.Stockholm University 31.Penn State University 32.Penn State University 33.Uppsala University 34.Utrecht University 35.University of Wuppertal 36.DESY Zeuthen
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE The IceCube Detector When complete 2012 – 80 in-ice strings – 6 deep core strings – 160 surface airshower tanks 2009 IC59 status – 58 normal in-ice strings – 1 DeepCore string – 118 surface tanks – 3730 channels in the DAQ – 1.8 kHz trigger rate (CR µ) – 15 MB/sec raw data to tape – 50 GB per day filtered data over satellite link from Pole – 300 atmospheric neutrinos per day at trigger level 2008 IC40 run complete now analyzing data from this period (5/08 – 5/09) JULY 2009 MG XIISLIDE 6
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE IceCube DeepCore Increase in detector eff. at 10 – 100 GeV IceCube strings form veto shield around core for 4π acceptance Ice extremely clear at depth (λ att > 150 m) Low-energy topics – Atmospheric neutrinos – Neutrino mass hierarchy – Dark matter – Low energy astrophysical fluxes JULY 2009 MG XIISLIDE 7
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Drilling and deployment JULY 2009 MG XII SLIDE 8
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Digital Optical Module technology JULY 2009 MG XII SLIDE 9 DOM Optical Large Area Photocathode 10 (500 cm 2 ) Hamamatsu R7081-02 bialkali PMT (peak QE 24% @ 420 nm); High QE variant (peak QE 35% @ 420 nm) used in DeepCore DOMs Low noise < 300 Hz background counting rate in-ice (with artificial deadtime - see later) Glass / Gel Improvements Better transmission in 330 - 400 nm relative to AMANDA OM Optical calibration Each DOM is calibrated ε(λ) in the lab to about 7%; in-situ flasher board additionally permits in-ice measurements DOM Electronics Smart sensor digital technology Versatile FPGA design with option to expand / change programming at any point in lifecycle. Core of supernova DAQ resides inside DOM itself. Array Timing Handled in DOM logic - DOM-to-DOM timing good to 2-3 ns using RAPCal method. Low power - 3.75 W / DOM 15 of 3776 DOMs are useless, 35 more have serious problems. As of June 2009 all DOMs have been produced.
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE TEV NEUTRINO ASTRO-PARTICLE PHYSICS WITH ICECUBE Part II JULY 2009 MG XII SLIDE 10
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Cosmic ray acceleration JULY 2009 MG XII SLIDE 11 Model of CR acceleration in shocks of SN remnants fits observation but not confirmed. TeV γ emission now established for many sources but could be from EM processes. Neutrino emission would be smoking gun for hadronic acceleration in these sources.
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE The neutrino sky JULY 2009 MG XII SLIDE 12
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE LINEAR TRACKSCASCADESDOUBLE-BANG Detecting TeV ν in IceCube JULY 2009 MG XII SLIDE 13 Neutrino undergoes CC or NC interaction with nuclear material, produces charged particles which emit Cherenkov radiation CC NC ν μ (or UHE ν τ ) produces μ or τ via CC scatter. which can travel for many kilometers along linear track radiating Cherenkov photons in conical wavefront about track. The extended range of taus and muons means vertex can lie far outside detector volume – detector effective area is key performance parameter. Angular resolution of 1° is achievable with sophisticated maximum likelihood track reconstruction. ν e CC or ν X NC nuclear interactions produce either EM or hadronic cascades. These produce enormous amounts of Cherenkov photons (10 8 photons per TeV) radiated over 4π. The extent of the cascade is ~10 m longer at UHE due to LPM. Detector effective volume is operational parameter for cascades. Good energy resolution – ice is caloric medium. Poor angular resolution VHE ν τ interacting inside the detector produces the primary recoil cascade and a τ which can propagate many 100s of m at HE. τ decay produces a secondary cascade – leaving a very distinct event. Other topologies as well: lollipop and sugar daddy. τ channel has no ATM background. UHE ν τ fluxes can regenerate and are not absorbed by passage through Earth.
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE 900 PeV cosmic ray event JULY 2009 MG XII SLIDE 14
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Atmospheric Neutrinos JULY 2009 MG XII SLIDE 15 Energy and baseline of atmospheric neutrinos: able to probe regions of parameter space for Lorentz violation and quantum decoherence completely inaccessible New techniques developed for unfolding the energy spectrum of atmospheric neutrinos – here from IC22 data. D. C HIRKIN ICRC 2009 H EULSNITZ & K ELLEY ICRC 2009
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Point Sources JULY 2009 MG XII SLIDE 16 Dumm ICRC 2009 ½ year of IC40 data – 175.5 d live time 17777 evts – 6796 up, 10981 down I CE C UBE P RELIMINARY
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Diffuse Neutrinos (IC22) Extraterrestrial neutrino flux harder than atmospheric neutrinos – look for HE excess of events Tricky analysis – very sensitive to systematics in Monte Carlo simulation IC22 diffuse results are just now being released (Hoshina 2009 ICRC) Use 3 simple energy estimators – N ch : # of hit channels – N pe : integral of reconstructed Q from DOM waveforms – µ dE/dX : muon energy loss from photon tables N ch and N pe showing significant excess at high multiplicity while µ dE/dX is consistent with atmopheric neutrino background (Continuing) investigation of systematics associated with very primitive channel, charge counting Limit from dE/dX analysis: JULY 2009 MG XIISLIDE 17
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Neutrinos from Gamma-Ray Bursts JULY 2009 MG XII SLIDE 18 Search for high-energy muon neutrinos from the naked-eye GRB080319B with the IceCube neutrino telescope arXiV:0902.0131 accepted by ApJarXiV:0902.0131 Right after deployment of the 40 strings last year the theoretically-visible-to-the-naked- eye GRB 080319B went off. Unfortunately IceCube was in maintenance mode at the time and only 9 strings were active. GRB fireball model predicts HE neutrinos from pγ interactions in GRB jet. Satellite-triggers (Fermi/SWIFT) used to pinpoint the burst search windows and reduce background (looser cuts possible)
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Neutrino-triggered optical follow-up IceCube trigger to optical network (ROTSE) on neutrino multiplet: 2 or more neutrino events inside 100 s and 4° space angle (25 accidentals / year for M=2) Motivation: GRBs, gamma-poor bursts, SNe with jets and TeV neutrino emission Program initiated end of 2008 JULY 2009 MG XIISLIDE 19
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Dark Matter JULY 2009 MG XII SLIDE 20
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE MEV NEUTRINO ASTRO-PARTICLE PHYSICS WITH ICECUBE Part III JULY 2009 MG XII SLIDE 21
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Supernovae JULY 2009 MG XII SLIDE 22 For star of mass > 8 M it is possible to develop Fe core ~ 1.4 M. Burning of Fe not exothermic – core collapses under its own gravity. Almost all (99%) of gravitational energy of collapsing core is radiated away as neutrinos – approx 10 53 erg. Not all supernovae are core collapse supernovae. Also Type Ia (used as standard candles in redshift measurements) which do not produce strong neutrino emission. Core collapse are Type Ib/c and Type II
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Observation of neutrinos from SN1987A JULY 2009 MG XII SLIDE 23
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Detection of MeV νs from SNe JULY 2009 MG XII SLIDE 24 Primary detection channel is inverse βdecay Note this is only sensitive to the electron anti- neutrinos. Electron neutrinos (in particular those from the de-leptonization burst) detected primarily from or The weak Cherenkov signal from any particular neutrino-nucleus interaction for IceCube-scale detector seen by at most one PMT. However, for sufficiently intense burst of finite duration, the counting rates of many such interactions recorded in many PMTs may be combined in manner to discriminate from background count rate.
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE IceCube DOM Effective Volume (MeV neutrinos) JULY 2009 MG XII SLIDE 25 Effective volume scales as photocathode area, attenuation length, and E 3, thus dependent on temperature of SNe. We compute in E- independent manner the single photon eff volume, V eff,γ (note PMT response already folded into this expression): = 0.185 m 3 SNe models give ~ 15 MeV One may easily derive approx photon yield from positrons: 2500 This gives per PMT, effective volume of 450 m 3 2 Mton target mass for IC86 500,000 counts above background expected for SN1987A at galactic center cf. rms noise fluctuation of 3700 S/N = 130 : 1
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Photon counting in IceCube PMT counts pulse crossing discriminator threshold of 0.25 pe DOM logic maintains virtual scalers: 4-bit counters with integration time 1.64 ms. Edges of bins defined in DOM clock frame – translation to global time via RAPCal method Introduction of artificial deadtime important to optimize S/N in presence of optical artifacts: PMT after-pulsing and other late light effects. The scalers from each channel collected and sent to assembly phase where they are chronologically sorted and then written to disk file (3 MB/sec) for – handoff to realtime supernova alert system – permanent storage JULY 2009 MG XIISLIDE 26
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Supernova detection in realtime JULY 2009 MG XII SLIDE 27 Internally we generate multiple triggers per day for monitoring purposes. Of these, high significance triggers sent to SNEWS via 24/7 Iridium satellite messaging system. SNEWS alert rate < 2 / week – average latency is approx. 10 min. Realtime supernova alert system at pole consumes data files emitted by DAQ system Merge and globally align scaler bins coming from DOMs Compute the following statistics to search for excess counts S IGNAL + ERROR B ACKGROUND ELIMINATION
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE SNe νs as probes of the supernova explosion mechanism JULY 2009 MG XII SLIDE 28 Various phases of evolution signaled by change in neutrino flux infall neutronization burst accretion cooling Theoretical models still have trouble producing explosion – neutrinos may be critical ingredient restarting the stalled shockwave For very massive stars > 25 M supernova explosion may be interrupted by formation of a black hole: optical burst not present – neutrino fluxes characterized by increase in temperature and eventual truncation.
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Particle physics with SN ν JULY 2009 MG XII SLIDE 29
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Conclusions Add these JULY 2009 MG XIISLIDE 30
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE SUPPLEMENTARY MATERIAL Backup please! JULY 2009 MG XII SLIDE 31
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE JULY 2009 MG XIISLIDE 32
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE RAPCal JULY 2009 MG XII SLIDE 33
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE RAPCal Analog Waveform JULY 2009 MG XII SLIDE 34
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Neutrino Effective Area JULY 2009 MG XII SLIDE 35
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE UHE Neutrino Cross Sections JULY 2009 MG XII SLIDE 36
UNIVERSITÉ LIBRE DE BRUXELLES, UNIVERSITÉ DEUROPE Tau neutrino events JULY 2009 MG XII SLIDE 37