Searches for Time Dependent Neutrino Sources with IceCube Data from 2008 to 2012

TL;DR

This study used four years of IceCube data to search for time-dependent astrophysical neutrino sources, focusing on flaring and periodic signals, but found no significant sources and set upper flux limits.

Contribution

It introduces time-dependent analysis methods for neutrino source detection and extends previous searches with more data from IceCube.

Findings

No significant time-dependent neutrino sources detected.

Upper limits set on neutrino flux from candidate sources.

Analysis covers four years of IceCube data.

Abstract

In this paper searches for flaring astrophysical neutrino sources and sources with periodic emission with the IceCube neutrino telescope are presented. In contrast to time integrated searches, where steady emission is assumed, the analyses presented here look for a time dependent signal of neutrinos using the information from the neutrino arrival times to enhance the discovery potential. A search was performed for correlations between neutrino arrival times and directions as well as neutrino emission following time dependent lightcurves, sporadic emission or periodicities of candidate sources. These include active galactic nuclei, soft $\gamma$-ray repeaters, supernova remnants hosting pulsars, micro-quasars and X-ray binaries. The work presented here updates and extends previously published results to a longer period that covers four years of data from 2008 April 5 to 2012 May 16 including the first year of operation of the completed 86-string detector. The analyses did not find any significant time dependent point sources of neutrinos and the results were used to set upper limits on the neutrino flux from source candidates.