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Kara Hoffman, the University of Maryland. the Antarctic Muon and Neutrino Array.

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Presentation on theme: "Kara Hoffman, the University of Maryland. the Antarctic Muon and Neutrino Array."— Presentation transcript:

1 Kara Hoffman, the University of Maryland

2 the Antarctic Muon and Neutrino Array

3 IceTop InIce Air shower detetor threshold ~ 300 TeV 70-80 Strings, 60 Optical Modules 17 m between Modules 125 m between Strings 2005-2006: 8 strings AMANDA 19 Strings 677 Modules 2006-2007: 13 strings 2007-2008: 18 strings 2008-2009: 19 strings 59 out of 86 strings operating 2004-2005: 1 string DeepCore 6 additional strings, 60 Optical Modules 7 or 10 m between Modules 72 m between Strings

4 Neutrino flavor Log(ENERGY/eV) 1218 15 6 21 9 e e   supernovae Full flavor ID Showers vs tracks IceCube flavor ID, direction, energy IceCube triggered, partial reconstruction TeV PeV

5 Very clear ice Dust concentration E reco = 500 TeV

6 Median angular resolution: (zenith angle averaged) MPE SPE E-1.5 ν – spectrum: 1.2° 2.4° E-2 ν – spectrum: 1.3° 1.7° Filter level- 40 string configuration Angular resolution improves with detector size. More sophisticated filtering includes a single iteration of a likelihood. Improved techniques improve angular resolution at high energies.

7 Existence of the moon confirmed!  deficit of events from direction of moon in the IceCube 40-string detector (3 months of data) confirms pointing accuracy. Validates pointing capabilities: Angular resolution: – IceCube 22 < 1.5° – IceCube 80 < 1°

8 e+e-e+e-    pair-creation bremsstrahlung photo-nuclear New variables are a stronger function of energy. Use information contained in the waveform instead of simply counting the number of hit phototubes.

9 Sky map with first 22 strings of the IceCube detector Hottest spot found at r.a. 153º, dec. 11º pre-trial p-value: 7x 10 -7 (4.8  ) est. nSrcEvents = 7.7 est.  = 1.65 Accounting for all trials, p-value for analysis is 1.34% (2.2  ). At this significance level, consistent with fluctuation of background. galactic plane 5114 neutrino candidates in 276 days livetime! new unbinned search method energy variables used

10 3.8 yr livetime 95% of RA-randomized skymaps have maximum significance > 3.38 σ → Not significant Significance 3yr max significance: 3.73   1.5  Max Significance  =54 o,  =11.4h 3.38  5yr max significance: 3.74   2.8  arXiv:0809.1646 6595 candidate events

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12 Earth becomes neutrino absorbing at high energies. High flux from atmospheric muons inhibits search above horizon. Background from atmospheric neutrinos irreducible over all sky. Use energy related variables to discriminate against softer atmospheric spectrum.

13 search in 2.5 degree bins background calculation from same declination band large irreducible background just below the horizon Coordinates: Dec. 1.00°, RA 103.5° (6.9 h) P-value: 2.9x10 -5 (pre-trial prob.) Bin content: 8 events with 1.2 expected (109 in dec. band) The trial-corrected probability for a random excess of the same or larger value anywhere in the sky from 390,000 scrambled maps: 37.4 %, i.e. not significant.

14 Down-going (sin(δ)<0 ) 90% energy interval: 50 TeV – 300 PeV Up-going ( sin(δ)>0 ) 90% energy interval: 8 TeV – 5 PeV Down-going (sin(δ)<0 ) 90% energy interval: 790 TeV – 5 EeV Up-going (sin(δ)>0 ) 90% energy interval: 32 TeV – 0.8 EeV E -2 E -1.5 In the PeV regime, point source searches can be extended above the horizon! Energy dependent variables invaluable!

15 Look for spatial and temporal coincidences with satellite observations- low background search New satellites, Swift, GLAST, improve observations cascade searches (triggered and rolling) yield flux limits that are 1-2 orders of magnitude higher Cascade (Trig & Roll) Cascade (Rolling)  search WB03 MN06 R03b R03a 400 bursts

16 IceCube will be sensitive to Waxman Bahcall fluxes within 1 year of full detector operation (~70 bursts)! 22 string detector configuration gains come from inclusion of energy variables and grb weighting

17 Detector was running in test mode (9 out of 22 strings taking data) Expect 0.1 events for Γ = 300 No neutrino candidate near GRB coordinates ➞ 90% upper flux limit Would expect ~1 event from similar burst in IceCube 80- strings GRB080319B March 19, 06:12:49 UT (duration ~70 s) Position: RA = 217.9°, Dec = +36.3° Brightest (optical) GRB ever observed z = 0.94 (DA = 1.6 Gpc)

18 Coincident triggers are selected for further CPU intensive reconstructions. If coming from same direction in the sky, an alert is sent to the ROTSE array. Quality cuts, time and space windows are set to allow ~30 random coincidences per year. 4 o angular window 100 ns time window 1.85 o x1.85 o ROTSE fov well matched to IC psf Increased sensitivity to transients Supernova (id: rising lightcurve) Gamma-Ray Burst (id: afterglow) Gamma-Dark Bursts (id: orphan afterglows)

19 search for neutrinos from unresolved point sources Energy related variables help distinguish atmospheric background from harder astrophysical flux.

20 bb WW annihilating in the gravity well of the Sun indirect detection Sun sinks maximally 23 o below the horizon at the South Pole-horizontal events very important Deep core enhancement under construction will greatly enhance sensitivity- see talk by Doug Cowen. 104 days livetime with 22 string configuration bb WW

21 atmospheric neutrino measurement important as background for other analyses look for nonstandard neutrino oscillations survival probability depends on energy and length of chord in the Earth VLI introduces velocity eigenstates distinct from mass and flavor new mixing angle  and phase  SuperK+K2K limit*:  c/c < 1.9  10 -27 (90%CL) This analysis:  c/c < 2.8  10 -27 (90%CL) IceCube: sensitivity of  c/c ~ 10 -28 Up to 700K atmospheric  in 10 years SuperK+K2K limit*:  c/c < 1.9  10 -27 (90%CL) This analysis:  c/c < 2.8  10 -27 (90%CL) IceCube: sensitivity of  c/c ~ 10 -28 Up to 700K atmospheric  in 10 years Limits on Violation of Lorentz Invariance assuming maximal mixing:

22 is the length of the bunch Add coherently! power proportional to the square of the shower energy Ongoing R&D for a future GZK energy neutrino detector focuses on radio Askaryan and acoustic detection. Propagation of sound and RF in cold ice are being studied using in situ measurements. Optimal technologies and array configurations under investigation. pressure v. time

23 instrumented depth: 80 m - 500 m per string: 7 sensors 7 transmitters Retrofit hardware developed for RICE, IceCube, and ANITA reuse IceCube hardware for time stamping, communications use ANITA digitization four antennas placed vertically along a string provide for up/down discrimination deployments at 250m and 1400m Transmitter: ring shaped piezo ceramic coated in resin HV generator Cold ice is the only medium in which acoustic, radio, and optical detection methods may be used simultaneously! Sensor: 3 channels / sensor pre-amplifier analogue signal transmission steel pressure housing

24 250m 1 low f channel 250m 1400m 1 low f channel 1400m Tx only Clusters consist of 4 receivers and 1 transmitter unless otherwise indicated Deployed in 06-07 and 08-09 austral summers Retrofit hardware developed for RICE, IceCube, and ANITA RICE array Radio Acoustic 3 clusters installed 06-07 austral summer 1 string with improved hardware installed 07-08 austral summer

25 time radio frequency

26 2008-2009 season successful with the addition of 19 new IceCube strings bringing the total to 59.2008-2009 season successful with the addition of 19 new IceCube strings bringing the total to 59. Many analyses of the 22 string configuration complete, thanks to data filtering at the Pole and subsequent satellite transmission. Analyses using 40 strings will be available shortly. Many analyses of the 22 string configuration complete, thanks to data filtering at the Pole and subsequent satellite transmission. Analyses using 40 strings will be available shortly. Analysis techniques are continually refined as we gain operational knowledge- improved analysis sensitivity.Analysis techniques are continually refined as we gain operational knowledge- improved analysis sensitivity. 1 cubic kilometer (80 strings) will be instrumented by 2011.1 cubic kilometer (80 strings) will be instrumented by 2011. Efforts are underway to develop the technology to build a GZK scale neutrino detector after IceCube is complete.Efforts are underway to develop the technology to build a GZK scale neutrino detector after IceCube is complete. See talk by Doug Cowen about a low energy enhancement that is already being implemented.See talk by Doug Cowen about a low energy enhancement that is already being implemented.

27 USA: Bartol Research Institute, Delaware University of California, Berkeley University of California, Irvine Pennsylvania State University Clark-Atlanta University Ohio State University Georgia Tech University of Maryland University of Alabama, Tuscaloosa University of Wisconsin-Madison University of Wisconsin-River Falls Lawrence Berkeley National Lab. University of Kansas Southern University and A&M College, Baton Rouge University of Alaska, Anchorage Sweden: Uppsala Universitet Stockholm Universitet UK: Oxford University Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut Germany: DESY-Zeuthen Universität Mainz Universität Dortmund Universität Wuppertal Humboldt Universität MPI Heidelberg RWTH Aachen Japan: Chiba University New Zealand: University of Canterbury 33 institutions, ~250 members http://icecube.wisc.edu Netherlands: Utrecht University Switzerland: EPFL

28 P (E i |  =2) P (E i |  =3) P atm (E i )


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