Search for neutrino point sources with IceCube 22-strings

TL;DR

This paper reports on the search for extraterrestrial neutrino point sources using IceCube's 22-string configuration data, employing multiple analysis methods, but finds no significant sources, setting new sensitivity limits.

Contribution

It introduces and compares binned and unbinned likelihood methods for neutrino source detection with IceCube data, achieving improved sensitivity limits.

Findings

No neutrino point sources detected.

Achieved the best sensitivity limits to date.

Limits improved by a factor of two over previous detectors.

Abstract

The IceCube detector took data in its 22-string configuration in 2007-2008. This data has been analyzed to search for extraterrestrial point sources of neutrinos using several methods. Two main methods are discussed and compared here: the binned and the unbinned maximum likelihood method. The best sky-averaged sensitivity (90% C.L.) is E^2 Phi_nu_mu=1.3 10^-11 TeVcm^-2s^-1 to a generic E^-2 flux of nu_mu over the energy range from 3 TeV to 3 PeV. No neutrino point sources are found from the individual directions of a pre-selected catalogue nor in a search extended to the northern sky. Limits are improved by a factor of two compared to the total statistics collected with the AMANDA-II detector and represent the best results to date.