Related papers: The Evolution of the BL Lacertae Objects
Evolution characteristics of a Kerr black hole (BH) are investigated by considering coexistence of disc accretion with the Blandford-Znajek process (the BZ process). (i) The rate of extracting energy from the rotating BH in the BZ process…
We propose a sequence (the Blazar main sequence, BMS) that links the two main components of the Blazar class, namely, the Flat Spectrum Radio Quasars and the BL Lacertae objects, and yields all their distinctive features in a correlated…
The Blandford-Znajek (BZ) mechanism in stellar-mass black hole (BH) hyperaccretion systems is generally considered to power gamma-ray bursts (GRBs). Based on observational GRB data, we use the BZ mechanism driven by the BH hyperaccretion…
We discuss the features that mark the Flat Spectrum Radio Quasars from the BL Lacertae objects. We propose that FSRQs exceeding L = 10^{46} erg/s are powered by black hole accreting at rates dm/dt = 1 - 10; their power is dominated by the…
BL Lac objects are active nuclei, hosted in massive elliptical galaxies, the emission of which is dominated by a relativistic jet closely aligned with the line of sight. This implies the existence of a parent population of sources with a…
A discussion of the FSRQ -- BL Lac unification. All distinctive features marking these two Blazar subclasses find an unifying explanation if the sources are powered by central engines constituted by similar Kerr holes, but fueled at high…
The Blandford-Znajek (BZ) process powers energetic jets by extracting the rotating energy of a Kerr black hole. It is important to understand this process in non-Kerr black hole spacetimes. In this study, we conduct two-dimensional and…
Blazar subclasses ranging from flat-spectrum radio quasars (FSRQs) through low-frequency-peaked BL Lac objects (LBLs) to high-frequency-peaked BL Lac objects (HBLs) exhibit a sequence of increasing spectral hardness with decreasing…
Black hole - accretion disc systems are the central engines of relativistic jets from stellar to galactic scales. We numerically quantify the unsteady outgoing Poynting flux through the horizon of a rapidly spinning black hole endowed with…
BL Lac objects are an elusive and rare class of active galactic nuclei. For years their evolutionary behavior has appeared inconsistent with the trend observed in the population of AGN at large. The so-called ``negative'' evolution implies…
We have analysed optical spectra of BL Lacertae, the prototype of its class, to verify the presence and possible flux variations of its broad Ha line. We used the spectroscopic information also to investigate the question of its parent…
The limits on the mass of the black hole in 23 BL Lac objects are obtained from their luminosities of the broad emission line H\beta on the assumption that broad emission lines are emitted from clouds ionized by the radiation of the…
The classical diagrams of radio loudness and jet power as a function of mass and accretion rate of the central spacetime singularity in active galactic nuclei are reanalyzed by including the data of the recently discovered powerful…
Blandford-Znajek (BZ) mechanism has usually been studied in the literature for accretion with considerably high angular momentum leading either to the formation of a cold Keplerian disc, or a hot and geometrically thick sub-Keplerian flow…
The most extreme active galactic nuclei (AGN) are the radio active ones whose relativistic jet propagates close to our line of sight. These objects were first classified according to their emission line features into flat-spectrum radio…
An analytic model of the evolution of a rotating black hole (BH) is proposed by considering the coexistence of disk accretion with the Blandford-Znajek process. The evolutionary characteristics of the BH are described in terms of three…
We derive quantitative predictions of the optical and X-ray luminosity functions (LF) for QSs in the redshift range $z<3$. Based on BH paradigm, we investigate how the accretion is controlled by the surrounding structures, as these grow…
We investigate the luminosity evolution of the host galaxies of radio-loud AGN through Hubble Space Telescope imaging of 72 BL Lac objects, including new STIS imaging of nine z > 0.6 BL Lacs. With their intrinsically low accretion rates and…
The effect of an accretion disk on the Blandford-Znajek process and the evolution of a black hole are discussed using a simplified system for the black hole - accretion disk in which the accretion rate is supposed to be dominated by the…
The BL Lacertae (BL Lac) object OJ 287 is one of the most dynamic blazars across the directly accessible observational windows: spectral, timing, polarization, and imaging. Apart from behaviors considered characteristics of blazars, it…