![]() Similar work is performed by Troitsky (2015), where the arrival directions of high-energy neutrinos are discussed, focusing on the possibility that neutrinos are not only extragalactic but they also can be produced in the halo or in the disk of our Galaxy. The analysis is repeated with different angular bins and the significance is never less than 3σ. In Neronov & Semikoz (2016), the angular distribution of the events observed by IceCube was analyzed, showing a significant excess of events on the galactic plane. This is the main reason why it is assumed that, in the first approximation, the (supposedly extragalactic) high-energy neutrinos seen by IceCube should be isotropically distributed (but note incidentally that also certain hypothetical sources in the Galaxy, such as the halo, might lead to a similar distribution). However, a common feature of these objects is to have an almost isotropic angular distribution in the sky, making a possible exception for the brightest among them, which could stand out. They differ greatly in physical and observable characteristics. 2014) of extreme stellar objects such as gamma-ray bursts (GRB Becker et al. 2016) of peculiar galaxies, such as starburst-galaxies (Loeb & Waxman 2006 Stecker 2007 Tamborra et al. ![]() ![]() The list of the candidate extragalactic sources of ultra-high-energy neutrinos comprises several disparate astrophysical objects, including various classes of active galactic nuclei (AGNs Stecker 2005, 2013) such as BL Lacertae objects (Padovani & Resconi 2014 Tavecchio et al. In this section we proceed to a critical assessment of the single-power-law model for high-energy neutrino emission, which, in view of its popularity and of the almost general acceptance at present, can be considered as the null hypothesis adopted for data analysis. A brief summary is contained in Section 5. In Section 4 we illustrate the predictions of our model for existing and future neutrino telescopes and the implications for gamma astronomy at the highest energy. In that section, we also quantify the relative intensity and discuss the spectra. In Section 3 we motivate and present the new hypothesis that includes two components: one due to extragalactic neutrinos and the other one due to galactic neutrinos. In Section 2 we examine the single-component hypothesis for high-energy neutrinos, stressing its shortcoming. The structure of this paper is as follows. Neutrino plus apk download latest version ![]() A particular very well-known implementation was the one developed in Waxman & Bahcall (1999). Before IceCube, the most popular expectations regarding ultra-high-energy neutrinos, typically adopted in sensitivity studies, were that (1) most of them have an extragalactic origin, as motivated by the existence of many extreme astrophysical objects and of extragalactic cosmic rays, and (2) their spectrum is distributed as E_\nu ^-2, as motivated by the expectations for cosmic rays at the sources and by Fermi's acceleration mechanism. ![]()
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