Angular correlation between IceCube high-energy starting events and starburst sources

作者：Moharana Reetanjali; Razzaque Soebur

来源：Journal of Cosmology and Astroparticle Physics, 2016, 2016(12): 021.

DOI：10.1088/1475-7516/2016/12/021

• neutrino astronomy
• ultra high energy photons and neutrinos

Starburst galaxies and star-forming regions in the Milkyway, with high rate of supernova activities, are candidate sources of high-energy neutrinos. Using a gamma-ray selected sample of these sources we perform statistical analysis of their angular correlation with the four-year sample of high-energy starting events (HESE), detected by the IceCube Neutrino Observatory. We find that the two samples (starburst galaxies and local starforming regions) are correlated with cosmic neutrinos at similar to(2 3) sigma(pre-trial) significance level, when the full HESE sample with deposited energy greater than or similar to 20TeV is considered. However when we consider the HESE sample with deposited energy greater than or similar to 60TeV, which is almost free of atmospheric neutrino and muon backgrounds, the significance of correlation decreased drastically. We perform a similar study for Galactic sources in the 2nd Catalog of Hard Fermi-LAT Sources (2FHL, > 50 GeV) catalog as well, obtaining similar to (2 3) sigma (pre-trial) correlation, however the significance of correlation increases with higher cut off energy in the HESE sample for this case. We also fit available gamma-ray data from these sources using a pp interaction model and calculate expected neutrino fluxes. We find that the expected neutrino fluxes for most of the sources are at least an order of magnitude lower than the fluxes required to produce the HESE neutrinos from these sources. This puts the starburst sources being the origin of the IceCube HESE neutrinos in question.

• 出版日期2016-12