相关论文: A model for periodic blazars

The spin precession of binary black holes (BBHs) that originate from isolated high-mass binary stars is determined by the interplay of phenomena such as tides, winds, accretion, common-envelope evolution, natal kicks, and stellar…

Recently the IceCube collaboration detected very high energy (VHE) neutrinos and associated them with the blazar \txs{}, raising a possible association of VHE neutrinos with this and other individual blazars. Very Long Baseline…

Aims. We wish to clarify the origin of the multiple jet features emanating from the binary protostar SVS 13A (= VLA4A/VLA4B). Methods. We used the Plateau de Bure Interferometer to map at 0.3-0.8" (~70-190 au) dust emission at 1.4 mm,…

We have not identified for sure what is the mechanism launching, accelerating and collimating relativistic jets. The two most likely possibilities are the gravitational energy of the accreting matter or the rotational energy of a spinning…

We present an investigation of the compact structure of the AGN 2021+317 based on multi-epoch Very Long Baseline Interferometry (VLBI) observations at 15, 22, and 43 GHz in the period from 2013 through 2024. The VLBI images show a core-jet…

In this paper we develop the extended jet model of Potter & Cotter to model the simultaneous multi-wavelength spectra of six Compton-dominant blazars. We include an accelerating parabolic base transitioning to a slowly decelerating conical…

The dissipation of energy flux in blazar jets plays a key role in the acceleration of relativistic particles. Two possibilities are commonly considered for the dissipation processes, magnetic reconnection -- possibly triggered by…

One of the most intriguing scenarios proposed to explain how active galactic nuclei are triggered involves the existence of a supermassive binary black hole system in their cores. Here we present an observational evidence for the first…

We examine the fundamental plane of 91 Blazars which include FSRQs and BL Lacs with known X-ray luminosity ($L_{R}$), radio luminosity ($L_X$), and black hole mass measurements ($M$) to reflect the relationship between jet and accretion for…

We fit the spectral energy distributions (SEDs) of members of a large sample of Fermi 2LAC blazars to synchrotron and inverse Compton (IC) models. Our main results are as follows. (i) As suggested by previous works, the correlation between…

Black hole jets represent one of the most extreme manifestations of astrophysical processes, linking accretion physics, relativistic magnetohydrodynamics, and large-scale feedback in galaxies and clusters. Despite decades of observational…

We compare the rise and decay timescales of $\sim$200 long-term ($\sim$weeks-months) GeV and R-band outbursts and $\sim$25 short-term ($\sim$hr-day) GeV flares in a sample of 10 blazars using light curves from the Fermi-LAT and the…

We present a unified picture to explain the spectral states of BH binaries based on the two-flow model. In our view, the central regions have a multi-flow configuration consisting in (1) an outer standard accretion disc (SAD) down to a…

Supermassive black holes at the centre of active galactic nuclei power some of the most luminous objects in the Universe. Typically, very long baseline interferometric (VLBI) observations of blazars have revealed only funnel-like…

Relativistic jets are thought to play a crucial role in the formation and evolution of massive galaxies and supermassive black holes. Blazars, which are quasars with jets aligned along our line of sight, provide insights into the jetted…

An electron-positron cascade in the magnetospheres of Kerr Black Holes (BH) is a fundamental ingredient to fueling the relativistic $\gamma$-ray jets seen at the polar regions of galactic supermassive BHs (SMBH). This leptonic cascade…

Three energy mechanisms invoking large-scale magnetic fields are incorporated in a model to interpret jet production in black hole (BH) systems, i.e., the Blandford-Znajek (BZ), the magnetic coupling (MC) and Blandford-Payne (BP) processes.…

PG1553+113 has drawn significant attention for its quasi-periodic oscillation (QPO) in gamma-ray variability, though the origin of its variability remains uncertain. In this study, we propose a physical mechanism to explain the observed…

Recent observations in the TeV band challenge the simplest models developed to describe the overall emission of blazars and radiogalaxies. In particular, the observation of variable TeV emission from M87 and the fast variability shown by…

Blazars are a class of active galactic nuclei which host relativistic jets oriented close to the observer's line of sight. Blazars have very complex variability properties. Flares, namely flux variations around the mean value with a…