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Kara Hoffman, the University of Maryland
the Antarctic Muon and Neutrino Array
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 string2004-2005: 1 string
DeepCore6 additional strings ,
60 Optical Modules
7 or 10 m between Modules
72 m between Strings
Neutrino flavor
Log(ENERGY/eV)
12 18156 219
e
e
supernovaeFull flavor ID
Showers vs tracks
IceCube flavor ID,direction, energy
IceCube triggered,partial reconstruction
TeV PeV
Veryclearice
Dust concentration
Ereco= 500 TeV
Median angular resolution:(zenith angle averaged) MPE SPEE-1.5 ν – spectrum: 1.2° 2.4°E-2 ν – spectrum: 1.3° 1.7°
Filter level- 40 string configurationFilter 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.
Existence of the moon confirmed!
deficit of events from direction of moon in the IceCube 40-stringdetector (3 months of data) confirms pointing accuracy.
Validates pointing capabilities:
Angular resolution:– IceCube 22 < 1.5°– IceCube 80 < 1°
e+e-
pair-creationbremsstrahlung
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.
Sky map with first 22 strings of the IceCube detector
Hottest spot found at r.a. 153º , dec. 11ºpre-trial p-value: 7x 10-7 (4.8 )
est. nSrcEvents = 7.7 est. = 1.65Accounting 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 methodnew unbinned search method
energy variables usedenergy variables used
• 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 Significanceδ=54o, α=11.4h 3.38
5yr max significance: 3.74 2.8
arXiv:0809.1646
6595 candidate events6595 candidate events
•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.
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 valueanywhere in the sky from 390,000 scrambled maps: 37.4 %, i.e. not significant.
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-2E-2
E-1.5E-1.5
In the PeV regime, point source searches can be extended above the horizon!Energy dependent variables invaluable!
•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
WB03
MN06
MN06
R03bR03b
R03aR03a 400 bursts400 bursts
•IceCube will be sensitive to Waxman Bahcall fluxes within 1 year of full detector operation (~70 bursts)!
•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
•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
GRB080319BGRB080319B
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)
•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.
•4o angular window•100 ns time window•1.85ox1.85o 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)
search for neutrinos from unresolved point sources
Energy related variables help distinguish atmospheric background from harder astrophysical flux.
bb
WW
•annihilating in the gravity well of the Sun•indirect detection
HZW
ll
,,
~~
±
→→→ χχ L
•Sun sinks maximally 23o
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
bbWW
•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*: δc/c < 1.9 10-27 (90%CL)
• This analysis: δc/c < 2.8 10-27 (90%CL)
• IceCube: sensitivity of δc/c ~ 10-28
Up to 700K atmospheric in 10 years
• SuperK+K2K limit*: δc/c < 1.9 10-27 (90%CL)
• This analysis: δc/c < 2.8 10-27 (90%CL)
• IceCube: sensitivity of δc/c ~ 10-28
Up to 700K atmospheric in 10 years
Limits on Violation of Lorentz Invariance assuming maximal mixing:
€
λ >> l
€
l 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
instrumented depth:•80 m - 500 mper 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 ceramiccoated 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
250m1 low f channel
250m
250m
1400m
1400m1 low f channel
1400mTx 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
time
time
time
time
radio frequency
•2008-2009 season successful with the addition of 19 new IceCube 2008-2009 season successful with the addition of 19 new IceCube strings bringing the total to 59.strings bringing the total to 59.
•Many analyses of the 22 string configuration complete, thanks to data Many analyses of the 22 string configuration complete, thanks to data filtering at the Pole and subsequent satellite transmission. Analyses filtering at the Pole and subsequent satellite transmission. Analyses using 40 strings will be available shortly.using 40 strings will be available shortly.
•Analysis techniques are continually refined as we gain operational Analysis techniques are continually refined as we gain operational knowledge- improved analysis sensitivity.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 Efforts are underway to develop the technology to build a GZK scale neutrino detector after IceCube is complete.neutrino detector after IceCube is complete.
•See talk by Doug Cowen about a low energy enhancement that is See talk by Doug Cowen about a low energy enhancement that is already being implemented.already being implemented.
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 Canterbury33 institutions, ~250 members
http://icecube.wisc.edu
Netherlands: Utrecht University
Switzerland: EPFL
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