Related papers: High-Energy Neutrino Emission from Blazars
Blazars constitute the vast majority of extragalactic $\gamma$-ray sources. They can also contribute a sizable fraction of the diffuse astrophysical neutrinos detected by IceCube. In the past few years, the real-time alert system of IceCube…
With infrared luminosities $L_{\mathrm{IR}} \geq 10^{12} L_{\odot}$, Ultra-Luminous Infrared Galaxies (ULIRGs) are the most luminous objects in the infrared sky. They are predominantly powered by starburst regions with star-formation rates…
We review and clarify the assumptions of our basic model for neutrino production in the cores of quasars, as well as those modifications to the model subsequently made by other workers. We also present a revised estimate of the neutrino…
Blazars are the most extreme subclass of active galactic nuclei with relativistic jets emerging from a super-massive black hole and forming a small angle with respect to our line of sight. Blazars are also known to be related to flaring…
Gamma-ray bursts (GRBs) are sources of energetic, highly variable fluxes of gamma rays, which demonstrates that they are powerful particle accelerators. Besides relativistic electrons, GRBs should also accelerate high-energy hadrons, some…
While observations in the radio band are providing essential information on the innermost structures of relativistic jets in active galactic nuclei (AGN), the recent detection by Fermi of gamma-ray emission from many hundreds of blazars…
The measured spectral energy distribution and variability time scale are used to determine the radiation and magnetic-field energy densities in the relativistic plasma that forms the gamma-ray emitting jet in the blazar 3C 279. Assuming…
Active galactic nuclei (AGNs) can power relativistic jets, which are called blazars when pointed close to our line of sight. Depending on the presence or absence of emission lines in their optical spectra, blazars are categorized into flat…
Three independent predictions follow from postulating the existence of protons co-accelerated with electrons in extragalactic jets (i) multi-TeV gamma ray emission from nearby blazars, (ii) extragalactic cosmic ray protons up to 10^20 eV,…
Astrophysical neutrinos can be produced in proton interactions of charged cosmic rays with ambient photon or baryonic fields. Cosmic rays are observed in balloon, satellite and air shower experiments every day, from below 1e9 eV up to…
The observation of high-energy neutrinos from the direction of the nearby active galaxy, NGC 1068, was a major step in identifying the origin of high-energy cosmic neutrinos. The multimessenger data imply that high-energy neutrinos…
The sources responsible for the emission of high-energy ($\gtrsim$ 100 TeV) neutrinos detected by IceCube are still unknown. Among the possible candidates, active galactic nuclei with relativistic jets are often examined, since the…
Blazars are sources whose jet is pointing to us. Since their jets are relativistic, the flux is greatly amplified in the direction of motion, making blazars the most powerful persistent objects in the Universe. This is true at all…
High-energy neutrinos present the ultimate signature for a cosmic ray accelerator. Galactic sources responsible for acceleration of cosmic ray up to the knee in cosmic ray spectrum will provide a guaranteed, albeit subdominant, contribution…
I describe a model of energetic gamma ray and neutrino emission in blazars which is consistent with most of the gamma-ray observations, and use this model to estimate the diffuse intensity of high energy neutrinos from blazars.
Relativistic jets from Active Galactic Nuclei (AGN) are highly energetic and emit radiation across a wide range of frequencies. Despite several observational studies, their particle composition still remains a key open question. The…
Eight years after the first detection of high-energy astrophysical neutrinos by IceCube we are still almost clueless as regards to their origin, although the case for blazars being neutrino sources is getting stronger. After the first…
Considering shock-accelerated protons in addition to electrons in a synchrotron radio jet naturally produces the observed X- through gamma ray continuum emission of flat-spectrum radio-loud AGN, whereas the corresponding shock-accelerated…
Blazars are a highly-variable, radio-loud subclass of active galactic nuclei (AGN). In order to better understand such objects we must be able to easily identify candidate blazars from the growing population of unidentified sources. Working…
The detection of high-energy neutrinos from NGC 1068 and TXS-0506+56 suggests that active galactic nuclei (AGN) may contribute significantly to the the diffuse neutrino flux measured by IceCube. Using 10 years of publicly available IceCube…