dumm_thesis.pdf

 The IceCube Neutrino Observatory is the first 1 km3 neutrino telescope. Data

were collected using the partially-completed IceCube detector in the 40-string configuration

recorded between 2008 April 5 and 2009 May 20, totaling 375.5 days livetime.

An unbinned maximum likelihood ratio method is used to search for astrophysical signals.

The data sample contains 36,900 events: 14,121 from the northern sky, mostly

muons induced by atmospheric neutrinos and 22,779 from the southern sky, mostly

high energy atmospheric muons. The analysis includes time-integrated searches for

individual point sources and targeted searches for specific stacked source classes and

spatially extended sources. While this analysis is sensitive to TeV–PeV energy neutrinos

in the northern sky, it is primarily sensitive to neutrinos with energy greater

than about 1 PeV in the southern sky. No evidence for a signal is found in any of

the searches. A number of searches are performed and significances (given as p-values,

the chance probability to occur with only background present) calculated: (1) a scan

of the entire sky for point sources (p=18%), (2) a predefined list of 39 interesting

source candidates (p=62%), (3) stacking 16 sources of TeV gamma rays observed by

Milagro and Fermi, along with an unconfirmed hot spot (p=32%), (4) stacking 127

starburst galaxies (p=100%), and (5) stacking five nearby galaxy clusters, testing

four different models for the CR distribution (p=78%). Limits are set for neutrino

fluxes from astrophysical sources over the entire sky and compared to predictions.

The sensitivity is at least a factor of two better than previous searches (depending

on declination), with 90% confidence level muon neutrino flux upper limits being between

E2dN/dE ∼ 2 − 200 Å~ 10−12 TeVcm−2 s−1 in the northern sky and between 3−700Å~10−12 TeVcm−2 s−1 in the southern sky. The stacked source searches provide

the best limits to specific source classes. For the case of supernova remnants, we are

just a factor of three from ruling out realistic predictions. The full IceCube detector

is expected to improve the sensitivity to E−2 sources by another factor of two in the

first year of operation.

• The data sample contains 36,900 events: 14,121 from the northern sky, mostly muons induced by atmospheric neutrinos and 22,779 from the southern sky, mostly high energy atmospheric muons.
• The analysis includes time-integrated searches for individual point sources and targeted searches for specific stacked source classes and spatially extended sources.
• While this analysis is sensitive to TeV�PeV energy neutrinos in the northern sky, it is primarily sensitive to neutrinos with energy greater than about 1 PeV in the southern sky.
• Limits are set for neutrino fluxes from astrophysical sources over the entire sky and compared to predictions.
• Teresa Montaruli (Adviser) i Abstract The IceCube...