Flavor composition and energy spectrum of astrophysical neutrinos

Context. The well known radiogalaxy Cen A has been recently detected as a source of very high energy (VHE) γ-rays by the HESS experiment just before Fermi/LAT detected it at high energies (HE). The detection, together with that of M 87, established radiogalaxies as VHE γ-ray emitters. Aims. The aim of this work is to present a lepto-hadronic model for the VHE emission from the relativistic jets in FR I radiogalaxies. Methods. We consider that protons and electrons are accelerated in a compact region near the base of the jet, and they cool emitting multi wavelength radiation as propagating along the jet. The proton and electron distributions are obtained through steady-state transport equation taking into account acceleration, radiative and non-radiative cooling processes, as well as particle transport by convection. Results. Considering the effects of photon absorption at different wavelengths, we calculate the radiation emitted by the primary protons and electrons, as well as the contribution of secondaries particles (e ± , πs and μs). The expected high-energy neutrino signal is also obtained and the possibility of detections with KM3NeT and IceCube is discussed. Conclusions. The spectral energy distribution obtained in our model with an appropriate set of parameters for an extended emission zone can account for much of the observed spectra for both AGNs.

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“…2 × 10 −6 s, and μ 3,4 = μ −,+ R (see Lipari et al 2007). The differential neutrino flux can be computed using a expression analogous to Eq.…”

Section: Neutrino Emissionmentioning

confidence: 99%

“…For muon injection, we proceed as (Lipari et al 2007) and we consider the production of left handed and right handed muons separately, which have different decay spectra:…”

Section: Particle Distributions In the Jetmentioning

confidence: 99%

A lepto-hadronic model for high-energy emission from FR I radiogalaxies

Reynoso

Medina

Romero

2011

A&A

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“…The injection of muons is calculated Table 1. using the expressions from Lipari et al (2007). The target fields are those of the corona in the case of matter, and the coronaplus-disk for photons.…”

Section: Particle Acceleration and Lossesmentioning

confidence: 99%

Non-thermal processes around accreting galactic black holes

Romero

Vieyro²,

Vila³

2010

A&A

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Context. Accreting black holes in galactic X-ray sources are surrounded by hot plasma. The innermost part of these systems is likely a corona with different temperatures for ions and electrons. In the so-called low-hard state, hot electrons Comptonize soft X-ray photons from the disk that partially penetrates the corona, producing emission up to ∼150 keV, well beyond the expectations for an optically thick disk of maximum temperature ∼10 7 K. However, sources such as Cygnus X-1 produce steady emission up to a few MeV, which is indicative of a non-thermal contribution to the spectral energy distribution. Aims. We study the radiative output produced by the injection of non-thermal (both electron and proton) particles in a magnetized corona around a black hole. Methods. Energy losses and maximum energies are estimated for all types of particles in a variety of models, characterized by different kinds of advection and relativistic proton content. Transport equations are solved for primary and secondary particles, and spectral energy distributions are determined and corrected by internal absorption. Results. We show that a local injection of non-thermal particles can account for the high energy excess observed in some sources, and we predict the existence of a high-energy bump at energies above 1 TeV, and typical luminosities of ∼10 33 erg s −1 . Conclusions. High-energy instruments such as the future Cherenkov Telescope Array (CTA) can be used to probe the relativistic particle content of the coronae around galactic black holes.

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“…The injection of muons is treated following Lipari et al (2007), considering left-handed and right-handed muons separately with their decay spectra:…”

Section: Muonsmentioning

confidence: 99%

A two-zone approach to neutrino production in gamma-ray bursts

Reynoso

2014

A&A

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Context. Gamma-ray bursts (GRB) are the most powerful events in the universe. They are capable of accelerating particles to very high energies, so are strong candidates as sources of detectable astrophysical neutrinos. Aims. We study the effects of particle acceleration and escape by implementing a two-zone model in order to assess the production of high-energy neutrinos in GRBs associated with their prompt emission. Methods. Both primary relativistic electrons and protons are injected in a zone where an acceleration mechanism operates and dominates over the losses. The escaping particles are re-injected in a cooling zone that propagates downstream. The synchrotron photons emitted by the accelerated electrons are taken as targets for pγ interactions, which generate pions along with the pp collisions with cold protons in the flow. The distribution of these secondary pions and the decaying muons are also computed in both zones, from which the neutrino output is obtained. Results. We find that for escape rates lower than the acceleration rate, the synchrotron emission from electrons in the acceleration zone can account for the GRB emission, and the production of neutrinos via pγ interactions in this zone becomes dominant for E ν > 10 5 GeV. For illustration, we compute the corresponding diffuse neutrino flux under different assumptions and show that it can reach the level of the signal recently detected by IceCube.

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Flavor composition and energy spectrum of astrophysical neutrinos

Cited by 218 publications

References 70 publications

A lepto-hadronic model for high-energy emission from FR I radiogalaxies

A lepto-hadronic model for high-energy emission from FR I radiogalaxies

Non-thermal processes around accreting galactic black holes

A two-zone approach to neutrino production in gamma-ray bursts

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