arXiv subjects
Publications and source records attributed to A. Turcati.
The Pacific Ocean Neutrino Experiment (P-ONE) is a new initiative with a vision towards constructing a multi-cubic kilometre neutrino telescope, to expand our observable window of the Universe to highest energies, installed within the deep Pacific Ocean underwater infrastructure of Ocean Networks Canada.
The association of two IceCube detections, the IceCube-170922A event and a neutrino flare, with the blazar TXS0506+056, has paved the way for the multimessenger quest for cosmic accelerators. IceCube has observed many other neutrinos but their origin remains unknown. To better understand the reason for the apparent lack of neutrino counterparts we have extended the comprehensive dissection of the sky area performed for the IceCube-170922A event to all the 70 public IceCube high-energy neutrinos that are well reconstructed and off the Galactic plane. Using the multi-frequency data available through the Open Universe platform, we have identified numerous candidate counterparts of IceCube events. We report here the classification of all the gamma-ray blazars found and the results of subsequent statistical tests. In addition, we have checked the 4LAC, 3FHL and 3HSP catalogues for potential counterparts. Following the dissection of all areas associated with IceCube neutrinos, we evaluate the data using a likelihood-ratio test and find a 3.23 sigma (post-trial) excess of HBLs and IBLs with a best-fit of 15 +/- 3.6 signal sources. This result, together with previous findings, consistently points to a growing evidence for a connection between IceCube neutrinos and blazars, the most energetic particle accelerators known in the Universe.
We test the recently proposed idea that outflows associated with Active Galactic Nuclei (AGN) could be neutrino emitters in two complementary ways. First, we cross-correlate a list of 94 "bona fide" AGN outflows with the most complete and updated repository of IceCube neutrinos currently publicly available, assembled by us for this purpose. It turns out that AGN with outflows matched to an IceCube neutrino have outflow and kinetic energy rates, and bolometric powers larger than those of AGN with outflows not matched to neutrinos. Second, we carry out a statistical analysis on a catalogue of O III 5007 line profiles using a sample of 23,264 AGN at z < 0.4, a sub-sample of which includes mostly possible outflows sources. We find no significant evidence of an association between the AGN and the IceCube events, although we get the smallest p-values (~ 6 and 18 per cent respectively, pre-trial) for relatively high velocities and luminosities. Our results are consistent with a scenario where AGN outflows are neutrino emitters but at present do not provide a significant signal. This can be tested with better statistics and source stacking. A predominant role of AGN outflows in explaining the IceCube data appears in any case to be ruled out.