Searching for PeV neutrinos from photomeson interactions in magnetars

Abstract

In this paper we estimate the flux of PeV neutrinos and gamma-rays from magnetar polar caps, assuming that ions/protons are injected, and accelerated in these regions and interact with the radiative background. The present study takes into account the effect of the photon splitting mechanisms that should modify the radiative background, and enhance the neutrino and gamma-ray fluxes at PeV energies, with a view to explain the PeV neutrino events detected in IceCube. The results indicate that in near future, possibility of any significant excess of neutrino events from a magnetar in Milky Way is extremely low. Further, we suggest that the simultaneous observation of neutrinos and gamma-rays at Earth from expanded 'Gen2' IceCube detector and/or High Altitude Water Cherenkov Observatory would provide opportunities to explore the possible origin of very high energy neutrinos and gamma-rays.

Diffuse flux of PeV neutrinos from centrifugally accelerated protons in active galactic nuclei

“…( 7), each neutrino will carry an amount of energy, E ν ≈ ǫ p,17 4 (1+z) PeV from an AGN in the appropriate luminosity range. As the charge-unchanging decay mode of ∆ + is more frequent (doubled) than the other channel, each twin gamma-ray photon should therefore carry relatively higher energy compared to a neutrino from the proton via π 0 decay at least in the vicinity of production sites [8]. We do not calculate the diffuse gamma ray flux here because a large fraction of produced PeV gamma rays from the distant AGN in particular, couldn't reach the Earth due to absorption en route.…”

“…These PeV energy neutrinos have triggered a serious attention among researchers especially with regard to the exploration of their astrophysical origins. Usually, the hadronic interaction processes like pγ and pp are considered to be in action in different astrophysical sites for the production of these UHE neutrinos [2,[6][7][8]. The active galactic nuclei (AGN) with appropriate bolometric luminosities (BLs) are considered in the present work as probable sources of extragalactic PeV neutrinos.…”

The search for high-energy neutrinos coincident with fast radio bursts with the ANTARES neutrino telescope

“…It corresponds to the giant flares from magnetars or the SGR models. The second scenario is related to some highly magnetised (B ∼ 10 14 G) neutron stars which are born with a millisecond timescale period of rotation making them able to power the particle acceleration and the subsequent highenergy neutrino emission (Dey et al, 2016). In both neutron star scenarios, a very high magnetic field is required with at least B > 10 14 G. For a magnetar, the typical values for the stellar radius and the magnetic field used here are B = 10 15 G, R = 10 km.…”

“…The rotational period, P, can vary from hundreds of milliseconds for a very young neutron star to few seconds for slow rotating magnetars (with P > 2 s). Based on these magnetar properties, the models of Zhang et al (2003); Dey et al (2016) predict a high-energy neutrino luminosity in the range L ν,quiescent ∈ [10 32 ; 10 35 ] erg s −1 when the magnetar is in the quiescent state. For a giant flare like the one observed from SGR 1806-20 (Palmer et al, 2005), the luminosity of the x-ray/γ-ray background (with E γ = 20 − 30 keV Zhang et al (2000)) can increase by at least a factor 10 6 in less than a second compared to the quiescent periods of the magnetar (Thompson, 2000).…”

“…In this case, TeV-PeV neutrinos can be produced by photohadronic interactions. These hadronic processes may occur in the energetic outflow released during a cataclysmic FRB event (Falcke & Rezzolla, 2014) or in the vicinity of the FRB progenitor through the interaction of the outflow with the surrounding environment (Zhang et al, 2003;Li et al, 2014;Murase et al, 2016;Dey et al, 2016). Based on their high rate, R FRB , and under the assumption that a fraction of FRBs are indeed efficient accelerators of TeV-PeV hadrons, they may contribute significantly to the cosmic diffuse neutrino signal discovered by the IceCube Collaboration (Aartsen et al, 2013(Aartsen et al, , 2015a(Aartsen et al, ,b,c, 2016.…”