In this paper, I present a qualitative discussion on the prospect of production of ultra-high
photons in blazars. The sources are a subclass of active galactic nuclei which host …

Bright blazars were found to be prominent neutrino sources, and a number of IceCube
events were associated with them. Evaluating high-energy photon emission of such blazars …

The evidence for joint gamma and neutrino emission from the blazar TXS 0506+ 056 has
renewed interest in blazars as neutrino sources. The detection of neutrinos from blazars can …

The possible association of the blazar TXS 0506+ 056 with a high-energy neutrino detected
by IceCube holds the tantalizing potential to answer three astrophysical questions: 1. Where …

Active galactic nuclei (AGN) with relativistic jets are the most powerful persistent
astrophysical sources of electromagnetic radiation in the Universe. Blazars are the most …

Various aspects of the high-energy emission from relativistic jets associated with compact
astrophysical systems are reviewed. The main leptonic and hadronic processes responsible …

An important radiation field for photomeson neutrino production in blazars is shown to be the
radiation field external to the jet. Assuming that protons are accelerated with the same power …

The radiation observed by blazars is believed to originate from the transformation of bulk
kinetic energy of relativistic jets into random energy. A simple way to achieve this is to have …

We present a strong hint of a connection between high-energy γ-ray emitting blazars, very
high energy neutrinos, and ultrahigh-energy cosmic rays. We first identify potential hadronic …

A neutrino with energy∼ 290 TeV, IceCube-170922A, was detected in coincidence with the
BL Lac object TXS 0506+ 056 during enhanced gamma-ray activity, with chance …