Implications ofFermi-LAT observations on the origin of IceCube neutrinos

Abstract

The IceCube (IC) collaboration recently reported the detection of TeV-PeV extraterrestrial neutrinos whose origin is yet unknown. By the photon-neutrino connection in pp and pγ interactions, we use the Fermi-LAT observations to constrain the origin of the IC detected neutrinos. We find that Galactic origins, i.e., the diffuse Galactic neutrinos due to cosmic ray (CR) propagation in the Milky Way, and the neutrinos from the Galactic point sources, may not produce the IC neutrino flux, thus these neutrinos should be of extragalactic origin. Moreover, the extragalactic gamma-ray bursts (GRBs) may not account for the IC neutrino flux, the jets of active galactic nuclei may not produce the IC neutrino spectrum, but the starburst galaxies (SBGs) may be promising sources. As suggested by the consistency between the IC detected neutrino flux and the Waxman-Bahcall bound, GRBs in SBGs may be the sources of both the ultrahigh energy, 10 19 eV, CRs and the 1 − 100 PeV CRs that produce the IC detected TeV-PeV neutrinos.

Can FSRQs produce the IceCube detected diffuse neutrino emission?

“…The sky distribution of the neutrino events is consistent with being isotropic (Aartsen et al 2014a) and hence of extragalactic origin, but the low statistics so far cannot make any solid conclusion. There are many models proposed to explain these diffuse neutrinos, e.g., produced by Galactic cosmic ray (CR) propagation or Galactic point sources (Gupta 2013;Neronov et al 2013;Ahlers and Murase 2014;Razzaque 2013;Lunardini et al 2013;Joshi et al 2014;Guo et al 2013;Taylor et al 2014), by extragalactic sources such as gamma-ray bursts (GRBs) (Waxman & Bahcall 1997;Murase & Ioka 2013;Cholis & Hooper 2013;, active galactic nuclei (AGN) jets (Murase et al 2014;Dermer et al 2014;Padovani & Resconi 2014;Mücke et al 2003) or cores (Stecker 2013), star forming galaxies He et al 2013;Anchordoqui et al 2014a;Tamborra et al 2014) and starbutrst galaxies (Loeb & Waxman 2006;Wang et al 2014), and by cosmogenic neutrinos from ultrahigh energy CR interactions with cosmic microwave background (CMB) (Kalashev et al 2013;Laha et al 2013;Roulet et al 2013). By using the Fermi-LAT observations and considering the gamma-ray and neutrino flux correlation, Wang et al (2014) suggested that only starburst galaxies and AGN jets in the above mentioned scenarios may produce the neutrino flux detected by IceCube.…”

Constraints on cosmic ray and PeV neutrino production in blazars

“…The arrival directions of the IceCube detected neutrinos are consistent with isotropic distribution [3]. The gammaray observations of diffuse Galactic emission and individual Galactic point sources by Fermi-LAT suggest that Galactic neutrino flux cannot account for the total flux IceCube detects [7]. These hint that the IceCube neutrinos are extragalactic origin, although some fraction could be Galactic origin [e.g .…”

高能中微子天文观测进展

“…河外起源的解释包括河外的点源, 例如伽玛 射线暴 [42,43] 、活动星系核 [44,45] 和恒星形成或星暴 星系 [46][47][48] , 也包括来自极高能宇宙线传播过程产生 的 GZK 中微子等 [49,50] . [51,52] , 结果发现以上提到的多种 中微子产生模型, 除了星暴星系之外都不被支持. 我们依据 Waxman 的观点 [53] 作一个较为宽泛 的讨论.…”