Could a plasma in quasi-thermal equilibrium be associated to the "orphan" TeV flares ?

TL;DR

This paper proposes a novel model involving a quasi-thermal plasma called Wein fireball at the base of blazar jets to explain 'orphan' TeV flares, linking gamma-ray, neutrino, and cosmic ray observations.

Contribution

It introduces a new mechanism involving a Wein fireball and proton-photon interactions to explain atypical blazar flares, extending beyond traditional models.

Findings

Successfully modeled 'orphan' TeV flares in specific blazars.

Predicted neutrino and UHECR fluxes consistent with current detector sensitivities.

Estimated thermal neutrino signals from the Wein fireball.

Abstract

TeV $\gamma$-ray detections in flaring states without activity in X-rays from blazars have attracted much attention due to the irregularity of these "orphan" flares. Although the synchrotron self-Compton model has been very successful in explaining the spectral energy distribution and spectral variability of these sources, it has not been able to describe these atypical flaring events. On the other hand, an electron-positron pair plasma at the base of the AGN jet was proposed as the mechanism of bulk acceleration of relativistic outflows. This plasma in quasi-themal equilibrium called Wein fireball emits radiation at MeV-peak energies serving as target of accelerated protons. In this work we describe the "orphan" TeV flares presented in blazars 1ES 1959+650 and Mrk421 assuming geometrical considerations in the jet and evoking the interactions of Fermi-accelerated protons and MeV-peak target photons coming from the Wein fireball. After describing successfully these "orphan" TeV flares, we correlate the TeV $\gamma$-ray, neutrino and UHECR fluxes through p$\gamma$ interactions and calculate the number of high-energy neutrinos and UHECRs expected in IceCube/AMANDA and TA experiment, respectively. In addition, thermal MeV neutrinos produced mainly through electron-positron annihilation at the Wein fireball will be able to propagate through it. By considering two- (solar, atmospheric and accelerator parameters) and three-neutrino mixing, we study the resonant oscillations and estimate the neutrino flavor ratios as well as the number of thermal neutrinos expected on Earth.